Содержание

FreeBSD is a free operating system derived from AT&T's UNIX operating system¹⁾. It runs on the following platforms:

• Computers based on the Intel i386 CPU architecture, including the 386, 486 and Pentium families of processors, and compatible CPUs from AMD and Cyrix.
• The Compaq/Digital Alpha processor.
• 64 bit SPARC machines from Sun Microsystems.
• In addition, significant development efforts are going towards porting FreeBSD to other hardware, notably the Intel 64 bit architecture and the IBM/Motorola PowerPC architecture.

This course describes the released versions of FreeBSD for Intel and Alpha processors. Current support for SPARC 64 processors is changing too fast for it to be practical to give details specific to this processor, but nearly everything in this course also applies to SPARC 64.

This course is intended for a number of different audiences. It attempts to present the material without too many forward references. It contains the following parts:

1. The first part, Chapters 1 to 6, tells you howtoinstall FreeBSD and what to do if things go wrong.
2. Chapters 7to15introduce you to life with FreeBSD, including setting up optional features and system administration.
3. Chapters 16 to 27 introduce you to FreeBSD's rich network support.
4. Finally, Chapters 28 to 33 look at system administration topics that build on all the preceding material.

In more detail, we'll discuss the following subjects:

• In the rest of this chapter, we’ll look at what FreeBSD is, what you need to run it, and what resources are available, including FreeBSD's features and history, how it compares to other free UNIX-like operating systems, other sources of information about FreeBSD, the world-wide FreeBSD community, and support for FreeBSD. In addition, we'll look at the BSD'sdaemon emblem.
• Chapter 2, Before you install, discusses the installation requirements and theoretical background of installing FreeBSD.
• Chapter 3, Quick installation, presents a quick overview of the installation process. If you're reasonably experienced, this may be all you need to install FreeBSD.
• In Chapter 4, Shared OS installation,we'll look at preparing to install FreeBSD on a system that already contains another operating system.
• In Chapter 5, Installing FreeBSD,we'll walk through a typical installation in detail.
• Chapter 6, Post-installation configuration,explains the configuration you need to do after installation to get a complete functional system.
• Chapter 7, The tools of the trade, presents a number of aspects of FreeBSD that are of interest to newcomers (particularly from a Microsoft environment). We'll look at setting up a desktop, the concept of users and file naming. We’ll also consider the basics of using the shell and editor, and how to shut down the machine.
• Chapter 8, Taking control, goes into more detail about the specifics of working with UNIX, such as processes, daemons, timekeeping and log files. We’ll also look at features unique to FreeBSD, including multiple processor support, removable I/O devices and emulating other systems.
• Chapter 9, The Ports Collection,describes the thousands of free software packages that you can optionally install on a FreeBSD system.
• Chapter 10, File systems and devices, contains information about the FreeBSD directory structure and device names. You'll find the section on device names (starting on page 195) interesting even if you're an experienced UNIX hacker.
• Chapter 11, Disks, describes how to format and integrate hard disks, and how to handle disk errors.
• Managing disks can be a complicated affair. Chapter 12, The Vinum Volume Manager, describes a way of managing disk storage.
• In Chapter 13, Writing CD-Rs, we'll look at how to use FreeBSD to write CD-Rs.
• FreeBSD provides professional, reliable data backup services as part of the base system. Don't ever let yourself lose data because of inadequate backup provisions. Read all about it in Chapter 14, Tapes, backups and floppy disks.
• Chapter 15, Printers, describes the BSD spooling system and how to use it both on local and networked systems.
• Starting at Chapter 16, Networks and the Internet, we’ll look at the Internet and the more important services.
• Chapter 17, Configuring the local network, describes how to set up local networking.
• Chapter 18, Connecting to the Internet, discusses the issues in selecting an Internet Service Provider (ISP) and establishing a presence on the Internet.
• Chapter 19, Serial communications, discusses serial hardware and the prerequisites for PPP and SLIP communications.
• In Chapter 20, Configuring PPP,welook at FreeBSD's two PPP implementations and what it takes to set them up.
• In Chapter 21, The Domain Name Service, we'll consider the use of names on the Internet.
• Security is an increasing problem on the Internet. In Chapter 22, Fire walls, IP aliasing and proxies,we'll look at some things we can do to improve it. We'll also look at IP aliasing, since it goes hand-in-hand with firewalls, and proxy servers.
• Networks sometimes become not works. In Chapter 23, Network debugging, we’ll see what we can do to solve net work problems.
• Chapter 24, Basic network access: clients,describes the client viewpoint of network access, including Web browsers, ssh, ftp, rsync and nfs clients for sharing file systems between networked computers.
• Network clients talk to network servers. We'll look at the corresponding server viewpoint in Chapter 25, Basic network access: servers.
• Despite the World Wide Web, traditional two-way personal communication is still very popular. We'll look at how to use mail clients in Chapter 26, Electronic mail: clients.
• Mail servers are an important enough topic that there's a separate Chapter 27, Electronic mail: servers.
• In Chapter 28, XFree86 in depth, we'll look at the theory behind getting X11 working.
• Chapter 29, Starting and stopping the system, describes how to start and stop a FreeBSD system and all the things you can do to customize it.
• In Chapter 30, FreeBSD configuration files, we'll look at the more common configuration files and what they should contain.
• In Chapter 31, Keeping up to date, we’ll discuss howtoensure that your system is always running the most appropriate version of FreeBSD.
• FreeBSD keeps changing. We'll look at some aspects of what that means to you in Chapter 32, Updating the system software.
• Chapter 33, Custom kernels, discusses optional kernel features.
• Appendix A, Bibliography,suggests some books for further reading.
• Appendix B, The evolution of FreeBSD, describes the changes that have taken place in FreeBSD since it was introduced nearly ten years ago.

FreeBSD is derived from Berkeley UNIX,the flavour of UNIX developed by the Computer Systems Research Group at the University of California at Berkeley and previously released as the Berkeley Software Distribution (BSD) of UNIX.

UNIX is a registered trademark of the Open Group, so legally; FreeBSD may not be called UNIX. The technical issues are different, of course; makeup your own mind as to how much difference this makes.

Like commercial UNIX, FreeBSD provides you with many advanced features, including:

• FreeBSD uses preemptive multitasking with dynamic priority adjustment to ensure smooth and fair sharing of the computer between applications and users.
• FreeBSD is a multi-user system:many people can use a FreeBSD system simultaneously for unrelated purposes. The system shares peripherals such as printers and tape drives properly between all users on the system.
• Don't get this confused with the multitasking offered by some commercial systems. FreeBSD is a true multi-user system that protects users from each other.
• FreeBSD is secure. Its track record is borne out by the reports of the CERT,the leading organization dealing with computer security. See http://www.cert.org for more information. The FreeBSD project has a team of security officers concerned with maintaining this lead.
• FreeBSD is reliable. It is used by ISPs around the world. FreeBSD systems regularly go several years without rebooting. FreeBSD can fail, of course, but the main causes of outages are power failures and catastrophic hardware failures.
• FreeBSD provides a complete TCP/IP networking implementation. This means that your FreeBSD machine can interoperate easily with other systems and also act as an enterprise server, providing vital functions such as NFS (remote file access) and electronic mail services, or putting your organization on the Internet with WWW, FTP, routing and firewall services. In addition, the Ports Collection includes software for communicating with proprietary protocols.
• Memory protection ensures that neither applications nor users can interfere with each other. If an application crashes, it cannot affect other running applications.
• FreeBSD includes the XFree86 implementation of theX11 graphical user interface.
• FreeBSD can run most programs built for versions of SCO UNIX and UnixWare, Solaris, BSD/OS, NetBSD, 386BSD and Linux on the same hardware platform.
• The FreeBSD Ports Collection includes thousands of ready-to-run applications.
• Thousands of additional and easy-to-port applications are available on the Internet. FreeBSD is source code compatible with most popular commercial UNIX systems and thus most applications require few, if any, changes to compile. Most freely available software was developed on BSD-like systems. As a result, FreeBSD is one of the easiest platforms you can port to.
• Demand paged virtual memory (VM)and "merged VM/buffer cache" design efficiently satisfies applications with large appetites for memory while still maintaining interactive response to other users.
• The base system contains a full complement of C, C++ and FORTRAN development tools. All commonly available programming languages, such as perl, python and ruby, are available. Many additional languages for advanced research and development are also available in the Ports Collection.
• FreeBSD provides the complete source code for the entire system, so you have the greatest degree of control overyour environment. The licensing terms are the freest that you will find anywhere ("Hey, use it, don't pretend you wrote it, don't complain to us if you have problems"). Those are just the licensing conditions, of course. As we'll see later in the chapter, there are plenty of people prepared to help if you run into trouble.
• Extensive online documentation, including traditional man pages and a hypertext-based online handbook.

FreeBSD is based on the 4.4BSD UNIX released by the Computer Systems Research Group (CSRG) at the University of California at Berkeley. The FreeBSD Project has spent many thousands of hours fine-tuning the system for maximum performance and reliability. FreeBSD's features, performance and reliability compare very favorably with those of commercial operating systems.

Since the source code is available, you can easily customize it for special applications or projects, in ways not generally possible with operating systems from commercial vendors. You can easily start out small with an inexpensive 386 class PC and upgrade as your needs grow. Here are a few of the applications in which people currently use FreeBSD:

• Internet Services: the Internet grew up around Berkeley UNIX. The original TCP/IP implementation, released in 1982, was based on 4.2BSD, and nearly every current TCP/IP implementation has borrowed from it. FreeBSD is a descendent of this implementation, which has been maintained and polished for decades. It is the most mature and reliable TCP/IP available at any price. This makes it an ideal platform for a variety of Internet services such as FTP servers, World Wide Web servers, electronic mail servers, USENET news servers, DNS name servers and firewalls. With the Samba suite, you can replace a Microsoft file server.
• Education: FreeBSD is an ideal way to learn about operating systems, computer architecture and networking. A number of freely available CAD, mathematical and graphic design packages also make it highly useful to those whose primary interest in a computer is to get other work done.
• Research: FreeBSD is an excellent platform for research in operating systems as well as other branches of computer science, since the source code for the entire system is available. FreeBSD's free availability also makes it possible for remote groups to collaborate on ideas or shared development without having to worry about special licensing agreements or limitations on what may be discussed in open forums.
• X Window workstation: FreeBSD makes an excellent choice for an inexpensive graphical desktop solution. UnlikeanXterminal, FreeBSD allows many applications to be run locally, if desired, thus relieving the burden on a central server. FreeBSD can even boot "diskless," making individual workstations even cheaper and easier to administer.
• Software Development: The basic FreeBSD system comes with a full complement of development tools including the renowned GNU C/C++ compiler and debugger.

As the name suggests, FreeBSD is free. You don't have to pay for the code, you can use it on as many computers as you want, and you can give away copies to your friends. There are some restrictions, however. Here's the BSD license as used for all new FreeBSD code:

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

This software is provided by the FreeBSD project "as is’ and any express or implied warranties, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose are disclaimed. In no event shall the FreeBSD project or contributors be liable for any direct, indirect, incidental, special, exemplary, or consequential damages (including, but not limited to, procurement of substitute goods or services; loss of use, data, or profits; or business interruption) however caused and on any theory of liability, whether in contract, strict liability, or tort (including negligence or otherwise) arising in anyway out of the use of this software, even if advised of the possibility of such damage.

The last paragraph is traditionally written in ALL CAPS, for reasons which don’t seem to have anything to do with the meaning. Older versions of the license also contained additional clauses relating to advertising.

FreeBSD is a labour of love: big commercial companies produce operating systems and charge lots of money for them; the FreeBSD project produces a professional-quality operating system and give sit away. That's not the only difference.

In 1981, when IBM introduced their Personal Computer, the microprocessor industry was still in its infancy. They entrusted Microsoft to supply the operating system. Microsoft already had their own version of UNIX, called XENIX, but the PC had a minimum of 16 kB and no disk. UNIX was not an appropriate match for this hardware. Microsoft went looking for something simpler. The "operating system "theychose was correspondingly primitive: 86/DOS, a clone of Digital Research’s successful CP/M operating system, written by Tim Paterson of Seattle Computer Products and originally called QDOS (Quick and Dirty Operating System). At the time, it seemed just the thing: it ran fine without a hard disk (in fact, the original PC didn't have a hard disk, not even as an option), and it didn't use up too much memory. The only thing that they really had to do was to change the name. IBM called its version PC-DOS, while Microsoft marketed its version under the name MS-DOS.

By this time, a little further down the US West Coast, the Computer Systems Research Group (CSRG) of the University of California at Berkeley had just modified AT&T's UNIX operating system to run on the new DEC VAX 11/780 machine, which sported virtual memory, and had turned their attention to implementing some new protocols for the ARPANET: the so-called Internet Protocols.The version of UNIX that they had developed was now sufficiently different from AT&T's system that it had been dubbed Berkeley UNIX.

As time went on, both MS-DOS and UNIX evolved. Before long, MS-DOS was modified to handle hard disks - not well, but it handled them, and for the PC users, it was so much better than what they had before that they ignored the inefficiencies. After all, the PC gave you your own hard disk on your desk, and you didn’t have to share it with all the other people in the department. Microsoft even tried to emulate the UNIX directory structure, but succeeded only in implementing the concept of nested directories. At Berkeley, they were developing a higher performance disk subsystem, the Fast File System, now known as the UNIX File System.

By the late 80s, it was evident that Microsoft no longer intended to substantially enhance MS-DOS. New processors with support for multitasking and virtual memory had replaced the old Intel 8088 processor of the IBM PC, but they still ran MS-DOS by emulating the 8088 processor, which was now completely obsolete. The 640 kB memory limit of the original PC, which once appeared bigger than anybody would ever need, became a serious problem. In addition, people wanted to do more than one thing at a time with their computers.

A solution to both problems was obvious: move to the 32 bit address mode of the new Intel 80386 processor and introduce real multitasking, which operating systems on larger machines had had for decades. Of course, these larger machines were only physically larger. The average PC of 1990 had more memory, more disk and more processing power than just about any of the large computers of the 70s. Nevertheless, Microsoft didn't solve these problems for its "Windows" platform until much later, and the solutions still leave a lot to be desired.

UNIX, on the other hand, was a relatively mature operating system at the time when the PC was introduced. As a result, Microsoft-based environments have had little influence on the development of UNIX. UNIX development was determined by other factors: changes in legal regulations in the USA between 1977 and 1984 enabled AT&T first to license UNIX to other vendors, noticeably Microsoft, who announced XENIX in 1981, and then to market its own version of UNIX. AT&T developed System III in 1982, and System V in 1983. The differences between XENIX and System V were initially small, but they grew: by the mid-80s, there were four different versions of UNIX: the Research Version, used almost only inside AT&T, which from the eighth edition on derived from 4.1cBSD, the Berkeley Software Distribution (BSD) from Berkeley, the commercial System V from AT&T, and XENIX, which no longer interested Microsoft, and was marketed by the company that had developed it, the Santa Cruz Operation, or SCO.

One casualty of UNIX’s maturity was the CSRG in Berkeley. UNIX was too mature to be considered an object of research, and the writing was on the wall: the CSRG would close down. Some people decided to port Berkeley UNIX to the PC—after all, SCO had ported its version of UNIX to the PC years earlier. In the Berkeley tradition, however, they wanted to give it away. The industry’s reaction was not friendly. In 1992, AT&T's subsidiary USL (UNIX Systems Laboratories)!! led a lawsuit against Berkeley Software Design, Inc. (BSDI), the manufacturer of the BSD/386 operating system, later called BSD/OS, a system very similar to FreeBSD. They alleged distribution of AT&T source code in violation of licence agreements. They subsequently extended the case to the University of California at Berkeley. The suit was settled out of court, and the exact conditions were not all disclosed. The only one that became public was that BSDI would migrate their source base to the newer 4.4BSD-Lite sources, a thing that they were preparing to do in any case. Although not involved in the litigation, it was suggested to FreeBSD that they should also move to 4.4 BSD-Lite, which was done with the release of FreeBSD release 2.0 in late 1994.

Now, in the early 21st century, FreeBSD is the best known of the BSD operating systems, one that many consider to follow in the tradition of the CSRG. I can think of no greater honour for the development team. It was developed on a shoestring budget, yet it manages to outperform commercial operating systems by an order of magnitude.

In the course of the FreeBSD project, a number of things have changed about UNIX. Sun Microsystems moved from a BSD base to a System V base in the late 80s, a move that convinced many people that BSD was dead and that System V was the future. Things turned out differently: in 1992, AT&T sold USL to Novell, Inc., who had introduced a product based on System V.4 called UnixWare. Although UnixWare has much better specifications than SCO's old System V3 UNIX, it was never success, and Novell finally sold their UNIX operation to SCO. SCO itself was then bought out by Caldera (which recently changed its name back to SCO), while the ownership of the UNIX trade mark has passed to the Open Group. System V UNIX is essentially dead: current commercial versions of UNIX have evolved so far since System V that they can't be considered the same system. By contrast, BSD is alive and healthy, and lives on in FreeBSD, NetBSD, OpenBSD and Apple's Mac OS X.

The importance of the AT&T code in the earlier versions of FreeBSD was certainly overemphasized in the lawsuit. All of the disputed code was over 10 years old at the time, and none of it was of great importance. In January 2002, Caldera released all "ancient" versions of UNIX under a BSD license. These specifically included all versions of UNIX from which BSD was derived: the first to seventh editions of Research UNIX and 32V, the predecessor to 3BSD. As a result, all versions of BSD, including those over which the lawsuit was conducted, are now freely available.

FreeBSD isn't the only free UNIX-like operating system available—it's not even the best-known one. The best-known free UNIX-like operating system is undoubtedly Linux, but there are also a number of other BSD-derived operating systems. We'll look at them first:

• 386/BSD was the original free BSD operating system, introduced by William F. Jolitz in 1992. It never progressed beyond a test stage: instead, two derivative operating systems arose, FreeBSD and NetBSD. 386/BSD has been obsolete for years.
• NetBSD is an operating system which, to the casual observer, is almost identical to FreeBSD. The main differences are that NetBSD concentrates on hardware independence, whereas FreeBSD concentrates on performance. FreeBSD also tries harder to be easy to understand for a beginner. You can find more information about NetBSD at http://www.NetBSD.org.
• Open BSD is a spin-off of NetBSD that focuses on security. It's also very similar to FreeBSD. You can find more information at http://www.OpenBSD.org.
• Apple computer introduced Version 10 (X) of its Mac OS in early 2001. It is a big deviation from previous versions of Mac OS: it is based on a Mach microkernel with a BSD environment. The base system (Darwin) is also free. FreeBSD and Darwin are compatible at the user source code level.

You could get the impression that there are lots of different, incompatible BSD versions. In fact, from a user viewpoint they're all very similar to each other, much more than the individual distributions of Linux, which we'll look at next.

In 1991, Linux Torvalds, then a student in Helsinki, Finland, decided he wanted to run UNIX on his home computer. Atthat time the BSD sources were not freely available, and so Linus wrote his own version of UNIX, which he called Linux.

Linux is a superb example of how a few dedicated; clever people can produce an operating system that is better than well-known commercial systems developed by a large number of trained software engineers. It is better even than a number of commercial UNIX systems.

Obviously, I prefer FreeBSD over Linux, or I wouldn't be writing this course , but the differences between FreeBSD and Linux are more a matter of philosophy rather than of concept. Here are a few contrasts:

FreeBSD comes with a considerable quantity of documentation which we'll look at in the following few pages:

• The FreeBSD Documentation Project maintains a collection of "books," documents in HTML or PDF format which can also be accessed online. They're installed in the directory hierarchy /usr/share/doc.
• The traditional UNIX document format is man pages, individual documents describing specific functionality. They’re short and to the point of being cryptic, but if you know what you're looking for, they have just the right amount of detail. They're not a good introduction.
• The GNU project introduced their own document format, GNU info. Some GNU programs have no other form of documentation.

You'll find a number of HTML documents in the directory /usr/share/doc/en/books:

• /usr/share/doc/en/books/faq/index.html contains the FreeBSD FAQ (Frequently Asked Questions). It's just what it says it is: a list of questions that people frequently ask about FreeBSD, with answers of course.
• /usr/share/doc/en/books/fdp-primer/index.html is a primer for the FreeBSD Documentation Project,
• /usr/share/doc/en/books/handbook/index.html is the FreeBSD online handbook. It contains a lot of information specifically about FreeBSD, including a deeper discussion of many topics in this course .
• /usr/share/doc/en/books/porters-handbook/index.html is a handbook for contributors to the FreeBSD Ports Collection, which we'll discuss in Chapter 9, The Ports Collection.
• /usr/share/doc/en/books/ppp-primer/index.html contains a somewhat dated document about setting up PPP. If you have trouble with Chapter 20, Configuring PPP, you may find it useful.

In addition to the directory /usr/share/doc/en/books, there's also a directory /usr/share/doc/en/articles with a number of shorter items of documentation.

Note the component en in the pathnames above. That stands for English.A number of these books are also installed in other languages: change en to de for a German version, to es for Spanish, to fr for French, to ja for Japanese, to ru for Russian, or to zh for Chinese. Translation efforts are continuing, so you may find documentation in other languages as well.

If you're running X, you can use a browser like mozilla to read the documents. If you don’t have Running yet, use lynx. Both of these programs are included in the CD-ROM distribution. To install them, use sysinstall, which is described on page 92.

lynx is not a complete substitute for complete web browsers such as mozilla:since it is text-only, it is not capable of displaying the large majority of web pages correctly. It's good enough for reading most of the FreeBSD online documentation, however.

In each case, you start the browser with the name of the document, for example:

$ lynx /usr/share/doc/en/books/handbook/index.html
$ mozilla /usr/share/doc/en/books/handbook/index.html &

Enter the & after the invocation of mozilla to free up the window in which you invoke it: mozilla opens its own window.

If you haven’t installed the documentation, you can still access it from the Live File system CD-ROM. Assuming the CD-ROM is mounted on /cdrom, choose the file /cdrom/usr/share/doc/en/books/handbook/index.html.

Alternatively, you can print out the handbook. This is a little more difficult, and of course you'll lose the hypertext references, but you may prefer it in this form. To format the handbook for printing, you'll need a PostScript printer or ghostscript. See page 271 for more details of how to print PostScript.

The printable version of the documentation doesn't usually come with the CD-ROM distribution. You can pick it up with ftp (see page 433) from ftp://ftp.FreeBSD.ORG/pub/FreeBSD/doc/,which has the same directory structure as described above. For example, you would download the handbook in PostScript form from ftp://ftp.FreeBSD.ORG/pub/FreeBSD/doc/en/books/handbook/book.ps.bz2.

The most comprehensive documentation on FreeBSD is the online manual, usually referred to as the man pages. Nearly every program, file, library function, device or interface on the system comes with a short reference manual explaining the basic operation and various arguments. If you were to print it out, it would run to well over 8,000 pages.

When online, you view the man pages with the command man. For example, to learn more about the command ls, type:

$ man ls
LS(1)   FreeBSD Reference Manual   LS(1)
NAME
   ls - list directory contents
SYNOPSIS
   ls [-ACFLRTacdfiloqrstu1][file ... ]
DESCRIPTION
   For each operand that names a file of a type other than directory, ls
   displays its name as well as any requested, associated information. For
   each operand that names a file of type directory, ls displays the names.
(etc)

In this particular example, with the exception of the first line, the text in constant width bold is not input, it's the way it appears on the screen.

The online manual is divided up into sections numbered:

1. User commands
2. System calls and error numbers
3. Functions in the C libraries
4. Device drivers
5. File formats
6. Games and other diversions
7. Miscellaneous information
8. System maintenance and operation commands
9. Kernel interface documentation

In some cases, the same topic may appear in more than one section of the online manual. For example, there is a user command chmod and a system call chmod(). In this case, you can tell the man command which you want by specifying the section number:

$ man 1 chmod 

This command displays the manual page for the user command chmod. References to a particular section of the online manual are traditionally placed in parentheses in written documentation. For example, chmod(l) refers to the user command chmod, and chmod(2) means the systcode call.

This is fine if you know the name of the command and forgot how to use it, but what if you can't recall the command name? You can use man to search for keywords in the command descriptions by using the -k option, or by starting the program apropos:

$ man -k mail $
apropos mail

Both of these commands do the same thing: they show the names of the man pages that have the keyword mail in their descriptions.

Alternatively, you may browse through the /usr/bin directory, which contains most of the system executables. You'll see lots of file names, but you don't have any idea what they do. To find out, enter one of the lines:

$ cd /usr/bin; man -f * 
$ cd /usr/bin; whatis *

Both of these commands do the same thing: they print out a one-line summary of the purpose of the program:

$ cd /usr/bin; man -f *
a2p(1)        - Awk to Perl translator
addftinfo(l)  - add information to troff font files for use with groff
apply(l)      - apply a command to a set of arguments
apropos(1)    - search the whatis database
...etc

If you prefer to have man pages in print, rather than on the screen, you can do this in two different ways:

• The simpler way is to redirect the output to the spooler:

  $ man ls | lpr

  This gives you a printed version that looks pretty much like the original on the screen, except that you may not get bold or underlined text.
• You can get typeset output with troff:

  $ man -t ls | lpr
  

  This gives you a properly typeset version of the man page, but it requires that your spooling system understand PostScript—see page 271 for more details of printing PostScript, even on printers that don't understand PostScript.

The Free Software Foundation has its own online hypertext browser called info. Many FSF programs come with either no man page at all, or with an excuse for a man page (gcc, for example). To read the online documentation, you need to browse the info files with the info program, or from Emacs with the info mode. To start info,simply type:

$ info

In Emacs, enter CTRL-h i or ALT-x info. Whichever way you start info, you can get brief introduction by typing h, and a quick command reference by typing ?.

FreeBSD users have access to probably more top-quality documentation than just about any other operating system. Remember that word UNIX is trademarked. Sure, the lawyers tell us that we can't refer to FreeBSD as UNIX, because UNIX belongs to the Open Group. That doesn't make the slightest difference to the fact that nearly every book on UNIX applies more directly to FreeBSD than any other flavour of UNIX. Why?

Commercial UNIX vendors have a problem, and FreeBSD doesn't help them: why should people buy their products when you can get it free from the FreeBSD Project (or, for that matter, from other free UNIX-like operating systems such as NetBSD, OpenBSD and Linux)? One obvious reason would be "value-added features." So they add features or fix weak points in the system, put a copyright on the changes, and help lock their customers in to their particular implementation. As long as the changes are really useful, this is legitimate, but it does make the operating system less compatible with "standard UNIX," and the books about standard UNIX are less applicable.

In addition, many books are written by people with an academic background. In the UNIX world, this means that they are more likely than the average user to have been exposed to BSD. Many general UNIX books handle primarily BSD, possibly with an additional chapter on the commercial System V version.

In Appendix A, Bibliography, you’ll find a list of books that I find worthwhile. I'd like to single out some that I find particularly good, and that I frequently use myself:

• UNIX Power 7oo/s, by Jeny Peek, Tim O'Reilly, and Mike Loukides, is a superb collection of interesting information, including a CD-ROM. Recommended for everybody, from beginners to experts.
• UNIX for the Impatient ,by Paul W. Abrahams and Bruce R. Larson, is more similar to this book, but it includes a lot more material on specific products, such as shells and the Emacs editor.
• The UNIX System Administration Handbook, by Evi Nemeth, Garth Snyder, Scott Seebass, and Trent R. Hein, is one of the best books on systems administration I have seen. It covers a number different UNIX systems, including an older version of FreeBSD.

There are also many active Internet groups that deal with FreeBSD. Read about them in the online handbook.

FreeBSD was developed by a world-wide group of developers. It could not have happened without the Internet. Many of the key players have never even met each other in person; the main means of communication is via the Internet. If you have any kind of Internet connection, you can participate as well. If you don't have an Internet connection, it's about time you got one. The connection doesn't have to be complete: if you can receive email, you can participate. On the other hand, FreeBSD includes all the software you need for a complete Internet connection, not the very limited subset that most PC-based "Internei" packages offer you.

As it says in the copyright, FreeBSD is supplied as-is, without any support liability. If you're on the Internet, you're not alone, however. Liability is one thing, but there are plenty of people prepared to help you, most for free, some for fee. A good place to start is with the mailing lists. There are a number of mailing lists that you can join. Some of the more interesting ones are:

• FreeBSD-questions@FreeBSD.org is the list to which you may send general questions, in particular on how to use FreeBSD. If you have difficulty understanding anything in this course , for example, this is the right place to ask. It's also the list to use if you're not sure which is the most appropriate.
• FreeBSD-questions@FreeBSD.org is a list for newcomers to FreeBSD. It's intended for people who feel a little daunted by the system and need a bit of reassurance. It's not the right place to ask any kind of technical question.
• FreeBSD-questions@FreeBSD.org is a technical discussion list.
• FreeBSD-questions@FreeBSD.org is an obligatory list for people who run the development version of FreeBSD, called FreeBSD-CURRENT.
• FreeBSD-questions@FreeBSD.org is a similar list for people who run the more recent stable version of FreeBSD, called FreeBSD-STABLE. We'll talk about these versions on page 582. Unlike the case for FreeBSD-CURRENT users, it's not obligatory for
• FreeBSD-STABLE users to subscribe to FreeBSD-stable.

You can find a complete list of FreeBSD mailing lists on the web site, currently at http://www.FreeBSD.org/doc/en_US.ISO8859-1/books/handbook/eresources.html. This address is part of the online handbook and may change when the handbook is modified; follow the link Mailing Lists from http://www.FreeBSD.org/ if it is no longer valid, or if you can't be bothered typing in the URI.

The mailing lists are run by mailman (in the Ports Collection). Join them via the web interface mentioned above. You will receive a mail message from mailman asking you to confirm your subscription by replying to the message. You don't need to put anything in the reply: the reply address is used once only, and you're the only person who will ever see it, so the system knows that it's you by the fact that you replied at all. You also have the option of confirming via a web interface with a specially generated URI. Similar considerations apply in this case.

FreeBSD mailing lists can have a very high volume of traffic. The FreeBSD-questions mailing list, for example, has thousands of subscribers, and many of them are themselves mailing lists. It receives over a hundred messages every day. That's about a million messages a day in total for just one mailing list, so when you sign up for a mailing list, be sure to read the charter. You can find the URI from the mailman confirmation message. It's also a good idea to "lurk" (listen, but not say anything) on the mailing list a while before posting anything: each list has its own traditions.

When submitting a question to FreeBSD-questions, consider the following points:

1. Remember that nobody gets paid for answering a FreeBSD question. They do it of their own free will. You can influence this free will positively by submitting a well-formulated question supplying as much relevant information as possible. You can influence this free will negatively by submitting an incomplete, illegible, or rude question. It's perfectly possible to send a message to FreeBSD-questions and not get an answer even if you follow these rules. It's much more possible to not get an answer if you don't.
2. Not everybody who answers FreeBSD questions reads every message: they look at the subject line and decide whether it interests them. Clearly, it's in your interest to specify a subject. "FreeBSD problem" or "Help" aren't enough. If you provide no subject at all, many people won’t bother reading it. If your subject isn'tspecific enough, the people who can answer it may not read it.
3. When sending a new message, well, send a new message. Don't just reply to some other message, erase the old content and change the subject line. That leaves an In-Reply-To: header which many mail readers use to thread messages, so your message shows up as a reply to some other message. People often delete messages a whole thread at a time, so apart from irritating people, you also run a chance of having the message deleted unread.
4. Format your message so that it is legible, and PLEASE DON'T SHOUT!!!!!. It's really painful to try to read a message written full of typos or without any line breaks. Alot of badly formatted messages come from bad mailers or badly configured mailers. The following mailers are known to send out badly formatted messages without you finding out about them:

   Eudora

   Exmh

   Microsoft Exchange

   Microsoft Internet Mail

   Microsoft Outlook

   Netscape

   As you can see, the mailers in the Microsoft world are frequent offenders. If at all possible, use a UNIX mailer. If you must use a mailer under Microsoft environments, make sure it is set up correctly. Try not to use MIME: a lot of people use mailers which don't get on very well with MIME.

   For further information on this subject, check out http://www.lemis.com/email.html.

5. Make sure your time and time zone are set correctly. This may seem a little silly, since your message still gets there, but many of the people you are trying to reach get several hundred messages a day.Theyfrequently sort the incoming messages by subject and by date, and if your message doesn't come before the first answer, they may assume they missed it and not bother to look.
6. Don’t include unrelated questions in the same message. Firstly, along message tends to scare people off, and secondly, it's more difficult to get all the people who can answer all the questions to read the message.
7. Specify as much information as possible. This is a difficult area: the information you need to submit depends on the problem. Here’s start:
   • If you get error messages, don't say "I get error messages", say (for example) "I get the error message No route to host".
   • If your system panics, don'tsay "My system panicked", say (for example) "my system panicked with the message free vnode isn't".
   • If you have difficulty installing FreeBSD, please tell us what hardware you have, particularly if you have something unusual.
   • If, for example, you have difficulty getting PPP to run, describe the configuration. Which version of PPP do you use? What kind of authentication do you have? Do you have a static or dynamic IP address? What kind of messages do you get in the log file? See Chapter 20, Configuring PPP, for more details in this particular case.
8. If you don't get an answer immediately, or if you don't even see your own message appear on the list immediately, don't resend the message. Wait at least 24 hours. The FreeBSD mailer offloads messages to a number of subordinate mailers around the world. Usually the messages come through in a matter of seconds, but sometimes it can take several hours for the mail to get through.
9. If you do all this, and you still don't get an answer, there could be other reasons. For example, the problem is so complicated that nobody knows the answer, or the person who does know the answer was offine. If you don't get an answer after, say, a week, it might help to re-send the message. If you don't get an answer to your second message, though, you're probably not going to get one from this forum. Resending the same message again and again will only make you unpopular.

Often you will want to send in additional information to a question you have already sent. The best way to do this is to reply to your original message. This has three advantages:

1. You include the original message text, so people will know what you're talking about. Don't forget to trim unnecessary text, though.
2. The text in the subject line stays the same (you did remember to put one in, didn't you?). Many mailers will sort messages by subject. This helps group messages together.
3. The message reference numbers in the header will refer to the previous message. Some mailers, such as mutt, can thread messages, showing the exact relationships between the messages.

There are more suggestions, in particular for answering questions, at http://www.lemis.com/questions.html. See also Chapter 26, Electronic mail: clients for more information about sending mail messages. You may also like to check out the FreeBSD web site at http://www.FreeBSD.org/ and the support page at http://www.FreeBSD.org/support.html.

In addition, a number of companies offer support for FreeBSD. See the web page http://www.FreeBSD.org/commercial/consulting_bycat.html for some possibilities.

There's a lot of traffic on the mailing lists, particularly on FreeBSD-questions. You may find you can't take it and want to get out again. Again, you unsubscribe from the list either via the web or via a special mail address, not by sending mail to the the list. Each message you get from the mailing lists finishes with the following text:

freebsd-questions@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-questions
To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"

Don't be one of those people who send the unsubscribe request to the mailing list instead.

But how about meeting FreeBSD users face to face? There are a number of user groups around the world. If you live in a big city, chances are that there's one near you. Check http://www.FreeBSD.org/support.html#user for a list. If you don't find one, consider taking the initiative and starting one.

In addition, USENIX holds an annual conference, the BSDCon, which deals with technical aspects of the BSD operating systems. It's also a great opportunity to get to know other users from around the world. If you're in Europe, there is also a BSDCon Europe, which at the time of writing was not run by USENIX. See http://www.eurobsdcon.org for more details.

If you find something wrong with FreeBSD, we want to know about it, so that we can fix it. To report a bug, use the send-pr program to send it as a mail message.

There used to be a web form at http://www.FreeBSD.org/send-pr.html, but it has been closed down due to abuse.

The little daemon at the right symbolizes BSD. It is included with kind permission of Marshall Kirk McKusick, one of the leading members of the former Computer Sciences Research Group at the University of California at Berkeley, and owner of the daemon's copyright. Kirk also wrote the foreword to this course .

The daemon has occasionally given rise to a certain amount of confusion. In fact, it's a joking reference to processes that run in the background—see Chapter 8, Taking control, page 150, for a description. The outside world occasionally sees things differently, as the following story indicates:

Newsgroups:   alt.humor.best-of-usenet
Subject:   [comp.org.usenix] A Great Daemon Story
From:   Rob Kolstad <kolstad@bsdi.com>
Newsgroups:   comp.org.usenix
Subject:   A Great Daemon Story

Linda Branagan is an expert on daemons. She has a T-shirt that sports the daemon in tennis shoes that appears on the cover of the 4.3BSD manuals and The Design and Implementation of the 4.3BSD UNIX Operating System by S. Leffler, M. McKusick, M. Karels, J. Quarterman, Addison Wesley Publishing Company, Reading, MA 1989.

She tells the following story about wearing the 4.3BSD daemon T-shirt:

Last week I walked into a local "home style cookin' restaurant/watering hole" in Texas to pick up a take-out order. I spoke briefly to the waitress behind the counter, who told me my order would be done in a few minutes.

So, while I was busy gazing at the farm implements hanging on the walls, I was approached by two "natives." These guys might just be the original Texas rednecks.

"Pardon us, ma'am. Mind if we ask you a question?"

Well, people keep telling me that Texans are real friendly, so I nodded.

"Are you a Satanist?"

Well, at least they didn't ask me if I liked to party.

"Uh, no, I can't say that I am."

"Gee, ma'am. Are you sure about that?" they asked.

I put on my biggest, brightest Dallas Cowboys cheerleader smile and said, "No, I'm positive. The closest I've ever come to Satanism is watching Geraldo."

"Hmmm. Interesting. See, we was just wondering why It is you have the lord of darkness on your chest there."

I was this close to slapping one of them and causing a scene—then I stopped and noticed the shirt I happened to be wearing that day. Sure enough, it had a picture of a small, devilish-looking creature that has for some time now been associated with a certain operating system. In this particular representation, the creature was wearing sneakers.

They continued: "See, ma'am, we don'texactly appreciate it when people showoff pictures of the devil. Especially when he'slookin' so friendly."

These idiots sounded terrifyingly serious.

Me: "Oh, well, see, this isn't really the devil, it's just, well, it's sort of a mascot.

Native: "And what kind of football team has the devil as a mascot?"

Me: "Oh, it's not a team. It's an operating—uh, a kind of computer."

I figured that an ATM machine was about as much technology as these guys could handle, and I knew that if I so much as uttered the word "UNIX" I would only make things worse.

Native: "Where does this satanical computer come from?"

Me: "California. And there's nothing satanical about it really."

Somewhere along the line here, the waitress noticed my predicament—but these guys probably outweighed her by 600 pounds, so all she did was look at me sympathetically and run off into the kitchen.

Native: "Ma'am, I think you're lying. And we'd appreciate it if you'd leave the premises now."

Fortunately, the waitress returned that very instant with my order, and they agreed that it would be okay for me to actually pay for my food before I left. While I was at the cash register, they am used themselves by talking to each other.

Native #1: "Do you think the police know about these devil computers?"

Native #2: "If they come from California, then the FBI oughta know about 'em."

Theye scorted me to the door. I tried one last time: "You're really blowing this all out of proportion. Alot of people use this 'kind of computers.' Universities, researchers, businesses. They're actually very useful."

Big, big, big mistake. I should have guessed at what came next.

Native:"Does the government use these devil computers?"

Me: "Yes."

Another big boo-boo.

Native:"And does the government pay for 'em? With our tax dollars?"

Idecided that it was time to jump ship.

Me: "No. Nope. Not at all. Your tax dollars never entered the picture at all. I promise. No sir, not a penny. Our good Christian congressmen would never let something like that happen. Nope. Never. Bye."

Texas. What acountry.

The daemon tradition goes back quite a way. Asrecently as 1996, after the publication of the first edition of this book, the following message went through the FreeBSD-chat mailing list:

To:   "Jonathan M. Bresler" <jmb@freefall.freebsd.org>
Cc:   obrien@antares.aero.org (Mike O'Brien),
    joerg_wunsch@uriah.heep.sax.de,
    chat@FreeBSD.org, juphoff@tarsier.cv.nrao.edu 
Date:   Tue, 07 May 1996 16:27:20 -0700
Sender:   owner-chat@FreeBSD.org
    >details and gifs PLEASE!
   If you insist. :-)
   Sherman, set the Wayback Machine for around 1976 or so (see Peter Salus' A 
Quarter Century of UNIX for details), when the first really national UNIX 
meeting was held in Urbana, Illinois. This would be after the "forty people 
in a Brooklyn classroom" meeting held by Mel Ferentz (yeah I was at that too) 
and the more-or-less simultaneous West Coast meeting(s) hosted by SRI, but before 
the UNIX Users Group was really incorporated as a going concern.
   I knew Ken Thompson and Dennis Ritchie would be there. I was living in Chicago 
at the time, and so was comic artist Phil Foglio, whose star was just beginning 
to rise. At that time I was a bonded locksmith. Phil's roommate had unexpectedly 
split town, and he was the only one who knew the combination to the wall safe in 
their apartment. This is the only apartment I've ever seen that had a wall safe, 
but it sure did have one, and Phil had some stuff locked in there. I didn't hold 
out much hope, since safes are far beyond where I was (and am) in my locks mithing 
sphere of competence, but I figured "no guts no glory" and told him I'd 
give it a whack. In return, I told him, he could do some T-shirt art for me. He readily agreed.
   Wonder of wonders, this safe was vulnerable to the same algorithm that Master 
locks used to be susceptible to. I opened it in about 15 minutes of manipulation. 
It was my greatest moment as a locksmith and Phil was overjoyed. I went down to my 
lab and shot some Polaroid snaps of the PDP-11 system I was running UNIX on at the 
time, and gave it to Phil with some descriptions of the visual puns I wanted: pipes, 
demons with forks running along the pipes, a "bit bucket" named /dev/null, all that.
   What Phil came up with is the artwork that graced the first decade's worth of 
"UNIX T-shirts," which were made by a Ma and Paoperation in a Chicago 
suburb. They turned out transfer art using a 3M color copier in their basement. 
Hence, the PDP-11 is reversed (the tape drives are backwards) but since Phil left off 
the front panel, this was hard to tell. His trademark signature was photo-reversed, 
but was recopied by the T-shirt people and "re-forwardized," which is why 
it looks a little funny compared to his real signature.
   Dozens and dozens of these shirts were produced. Bell Labs alone accounted for 
an order of something like 200 for a big picnic. However, only four (4) REAL 
originals were produced: these have a distinctive red collar and sleeve cuff. 
One went to Ken, one to Dennis, one to me, and one to my then-wife. I now possess 
the latter two shirts. Ken and Dennis were presented with their shirts at the Urbana conference.
People ordered these shirts direct from the Chicago couple. Many years later, 
when I was living in LA, I got a call from Armando Stettner, then at DEC, 
asking about that now-famous artwork. I told him I hadn't talked to the Illinois 
T-shirt makers in years. At his request I called them up. They'd folded the operation 
years ago and were within days of discarding all the old artwork. I requested its return, 
and duly received It back in the mail. It looked strange, seeing it again in its 
original form, a mirror image of the shirts with which I and everyone else were now familiar.
I sent the artwork to Armando, who wanted to give it to the Ultrix marketing people. 
   They came out with the Ultrix poster that showed a nice shiny Ultrix machine 
contrasted with the chewing-gum-and-string PDP-11 UNIX people were familiar with.
They still have the artwork, so far as I know.
   I no longer recall the exact contents of the letter I sent along with the artwork. 
I did say that as far as I knew, Phil had no residual rights to the art, 
since it was a 'work made for hire', though nothing was in writing 
(and note this was decades before the new copyright law). I do not now recall 
if I explicitly assigned all rights to DEC. What is certain is that John Lassiter's daemon, 
whether knowingly borrowed from the original, or created by parallel evolution, 
postdates the first horde of UNIX daemons by at least a decade and probably more. 
And if Lassiter's daemon looks a lot like a Phil Foglio creation, there's are a son.
   I have never scanned in Phil's artwork; I've hardly ever scanned in anything, 
so I have no GIFs to show. But I have some very very old UNIX T-shirts in 
startlingly good condition. Better condition than I am at any rate: 
I no longer fit into either of them.

Mike O'Brien
Creaky antique

Note the date of this message: it appeared since the first edition of this book. Since then, the daemon image has been scanned in, and you can find a version at http://www.mckusick.com/beastie/shirts/usenix.html

FreeBSD runs on just about any modern PC, Alpha or 64 bit SPARC machine. You can skip this chapter and the next and move to chapter 3, and you'll have a very good chance of success. Nevertheless, it makes things easier to know the contents of this chapter before you start. If you do run into trouble, it will give you the background information you need to solve the trouble quickly and simply.

FreeBSD also runs on most Intel-based laptops; in general the considerations above apply for laptops as well. In the course of the book we'll see examples of where laptops require special treatment.

Most of the information here applies primarily to Intel platforms. We'll look at the Compaq Alpha architecture on page 42. The first release of FreeBSD to support the SPARC 64 architecture is 5.0, and support is still a little patchy. At the time of going to press, it's not worth describing, since it will change rapidly. The instructions on the CD-ROM distribution are currently the best source of information on running FreeBSD on SPARC 64.

FreeBSD runs on all relatively recent machines. In addition, a lot of older hardware that is available for a nominal sum, or even for free, runs FreeBSD quite happily, though you may need to take more care in the installation.

FreeBSD does not support all PC hardware: the PC has been on the market for over 20 years, and it has changed a lot in that time. In particular:

• FreeBSD does not support 8 bit and 16 bit processors. These include the 8086 anв 8088, which were used in the IBM PC and PC-XT and clones, and the 80286, used in the IBM PC-AT and clones.
• The FreeBSD kernel no longer supports ST-506 and ESDI drives. You're unlikely to have any of these: they're now so old that most of them have failed. The wd driver still includes support for them, but it hasn't been tested, and if you want to use this kind of drive you might find it better to use FreeBSD Release 3. See page 32 to find out how to identify these drives. You can get Release 3 of FreeBSD from ftp://ftp.FreeBSD.org/pub/FreeBSD/releases/i386/3.x-STABLE. You'll have toper-form a network installation.
• Memory requirements for FreeBSD have increased significantly in the last few years, and you should consider 16 MB a minimum size, though nobody has recently checked whether it wouldn't install in, say,12MB. FreeBSD Release 3 still runs in 4 MB, though you need 5 MB for installation.

If you're planning to install FreeBSD on an old machine, consider the following to be an absolute minimum:

• PC with 80386 CPU, Alpha-based machine with SRM firmware.
• 16 MB memory (Intel) or 24 MB (Alpha).
• 80 MB free disk space (Intel). Nobody has tried an installation on an Alpha or SPARC machine with less than 500 MB, though you can probably reduce this value significantly.

You don't absolutely need a keyboard and display board: many FreeBSD machines run server tasks with neither keyboard nor display. Even then, though, you may find it convenient to put a display board in the machine to help in case you run into trouble.

When I say absolute minimum, I mean it. You can't do very much with such a minimal system, but for some purposes it might be adequate. You can improve the performance of such a minimal system significantly by adding memory. Before you go to the trouble to even try such a minimal installation, consider the cost of another 16 MB of memory. And you can pick up better machines than this second-hand for $50. Is the hassle worth it?

To get full benefits from a desktop or laptop FreeBSD system (but not from a machine used primarily as a server), you should be running the X Window system. This uses more memory. Consider 32 MB a usable minimum here, though thanks to FreeBSD's virtual memory system, this is not such a hard limit as it is with some other systems.

Any SPARC 64 machine runs FreeBSD acceptably, as the machines are relatively new. If you're running Intel or Alpha, consider the following the minimum for getting useful work done with FreeBSD and X:

• PC with 80486DX/2-66, or Alpha-based machine
• 32 MB memory (i386) or 64 MB (Alpha)
• SVGA display board with 2 MB memory, 1024x768
• Mouse
• 200 MB free disk space

Beyond this minimum, FreeBSD supports a large number of other hardware components.

The FreeBSD kernel is the only part of the system that can access the hardware. It includes device drivers, which control the function of peripheral devices such as disks, displays and network boards. When you install new hardware, you need a driver for it.

There are two ways to get a driver into the kernel: you can build a kernel that includes the driver code, or you can load a driver module (Kernel Loadable Module or kld) into the kernel at run time. Not all drivers are available as klds. If you need one of these drivers, and it's not included in the standard kernel, you have to build a new kernel. We look at building kernels in Chapter 33.

The kernel configuration supplied with FreeBSD distributions is called GENERIC after the name of the configuration file that describes it. It contains support for most common devices, though support for some older hardware is missing, usually because it conflicts with more modern drivers. For a full list of currently supported hardware, read the web page http://www.FreeBSD.org/releases/ and select the link Hardware Notes for the release you're interested in. This file is also available on installed FreeBSD systems as /usr/share/doc/en_US.ISO_8859-1/books/faq/hardware.html. It is also available in other languages; see the subdirectories of /usr/share/doc.

This section looks at the information you need to understand to install FreeBSD on the i386 architecture. In particular, in the next section we'll look at how FreeBSD detects hardware, and what to do if your hardware doesn't correspond to the system's expectations. On page 32 we'll see how FreeBSD and other PC operating systems handle disk space, and how to set up your disk for FreeBSD.

Some of this information also applies to the Alpha and SPARC 64 architectures. We'll look at the differences for the Alpha architecture on page 42. Currently the SPARC 64 implementation is changing too fast to describe it in a meaningful manner.

Since the original PC, a number of hardware standards have come, and some have gone:

• The original PC had an 8 bit bus. Very few of these cards are still available, but they are compatible with the ISA bus (see the next item).
• The PC AT, introduced in 1984, had a 16 bit 80286 processor. To support this processor, the bus was widened to 16 bits. This bus came to be known as the Industry Standard Architecture, or ISA.This standard is still not completely dead, and many new mother boards support it. Most older motherboards have a number of ISA slots.
• The ISA bus has a number of severe limitations, notably poor performance. This became a problem very early. In 1985, IBM introduced the PS/2 system, which addressed this issue with a new bus, the so-called Micro Channel Architecture or MCA. Although successful for IBM, MCA was not adopted by other manufacturers, and FreeBSD does not support it at all. IBM no longer produces products based on MCA
• In parallel to MCA, other manufacturers introduced a bus called the Extended Industry Standard Architecture, or EISA. As the name suggests, it is a higher-performance extension of ISA, and FreeBSD supports it. Like MCA, it is obsolete.
• EISA still proved to be not fast enough for good graphics performance. In the late 80s, a number of local bus solutions appeared. They had better performance, but some were very unreliable. FreeBSD supported most of them, but you can't rely on it. It's best to steer clear of them.
• Finally, in the early 1990s, Intel brought out a new bus called Peripheral Component Interconnect, or PCI. PCI is now the dominant bus on a number of architectures. Most modern PC add-on boards are PCI.
• Compared to earlier buses, PCI is much faster. Most boards have a 32bit wide data bus, but there is also a 64 bit PCI standard. PCI boards also contain enough intelligence to enable the system to configure them, which greatly simplifies installation of the system or of new boards.
• Modern motherboards also have an AGP (Accelerated Graphics Port) slot specifically designed to support exactly one graphic card. As the name implies, it's faster even than PCI, but its optimized for graphics only. FreeBSD supports it, of course otherwise it couldn't run on modern hardware.
• Most laptops have provision for external plug-in cards that conform to the PC Card (formerly called PCMCIA) or CardBus standards. These cards are designed to be inserted into and removed from a running system. FreeBSD has support for these cards; we'll look at them in more detail on page 30.
• More and more, the basic serial and parallel ports installed on early PCs are being replaced by a Universal Serial Bus or USB. We’ll look at it on page 31.

When the system starts, each driver in the kernel examines the system to find any hardware that it might be able to control. This examination is called probing. Depending on the driver and the nature of the hardware it supports, the probe may be clever enough to set up the hardware itself, or to recognize its hardware no matter how it has been set up, or it may expect the hardware to be set up in a specific manner in order to find it. In general, you can expect PCI drivers to be able to set up the card to work correctly. In the case of ISA or EISA cards, you may not be as lucky.

ISA cards are rapidly becoming obsolete, but sometimes they're still useful:

• ISA graphics cards are very slow in comparison with modern graphic cards, but if you just want a card for maintenance on a server machine that normally doesn't display anything, this is an economical alternative.
• Some ISA disk controllers can be useful, but they are sharply limited in performance.
• ISA Ethernet cards may be a choice for low-volume networking.
• Many ISA serial cards and built-in modems are still available.

Most ISA cards require some configuration. There are four main parameters that you may need to set for PC controller boards:

1. The port address is the address of the first of possibly several control registers that the driver uses to communicate with the board. It is normally specified in hexadecimal, for example 0x320
   If you come from a Microsoft background, you might be more used to the notation 320H. The notation 0x320 comes from the C programming language. You’ll see a lot of it in UNIX

   Each board needs its own address or range of addresses. The ISA architecture has a sharply limited address range, and one of the most frequent causes of problems when installing a board is that the port addresses overlap with those of another board

   Beware of boards with a large number of registers. Typical port addresses end in (hexadecimal) 0. Don't rely on being able to take any unoccupied address ending in 0, though: some boards, such as Novell NE2000 compatible Ethernet boards, occupy up to 32 registers—or example, from 0x320 to 0x33f. Note also that a number of addresses, such as the serial and parallel ports, often end in 8.

2. Boards use an Interrupt Request, also referred to as IRQ, to get the attention of the driver when a specific event happens. For example, when a serial interface reads a character it generates an interrupt to tell the driver to collect the character. Interrupt requests can sometimes be shared, depending on the driver and the hardware. There are even fewer interrupt requests than port addresses: a total of 15, of which a number are reserved by the motherboard. You can usually expect to be able to use IRQs 3, 4, 5, 7, 9, 10, 11 and 12. IRQ 2 is special: due to the design of the original IBM PC/AT, it is the same thing as IRQ 9. FreeBSD refers to this interrupt as IRQ 9

   As if the available interrupts weren't already restricted enough, ISA and PCI boards use the same set of interrupt lines. PCI cards can share interrupt lines between multiple boards, and in fact the PCI standard only supports four interrupts, called INTA, INTB, INTC and INTD. In the PC architecture they map to four of the 15 ISA interrupts. PCI cards are self-configuring, so all you need to do is to ensure that PCI and ISA interrupts don't conflict. You normally set this up in a BIOS setup menu.

3. Some high-speed devices perform Direct Memory Access, also known as DMA, to transfer data to or from memory without CPU intervention. To transfer data, they assert a DMA Request (DRQ) and wait for the bus to reply with a DMA Acknowledge (DACK). The combination of DRQ and DACK is sometimes called a DMA Channel. The ISA architecture supplies 7 DMA channels, numbered 0 to 3 (8 bit) and 5 to 7 (16 bit). The floppy driver uses DMA channel 2. DMA channels may not be shared.
4. Finally, controllers may have on-board memory, sometimes referred to as I/O memory or IOmem. It is usually located at addresses between 0xa0000 and 0xeffff.

If the driver only looks at specific board configurations, you can set the board to match what the driver expects, typically by setting jumpers or using a vendor-supplied diagnostic program to set on-board configuration memory, or you can build a kernel to match the board settings.

Laptops don't have enough space for normal PCI expansion slots, though many use a smaller PCI card format. It's more common to see PC Card or CardBus cards, though. PC Card was originally called PCMCIA, which stands for Personal Computer Memory Card International Association: the first purpose of the bus was to expand memory. Nowadays memory expansion is handled by other means, and PC Card cards are usually peripherals such as network cards, modems or disks. It's true that you can insert compact flash memory for digital cameras into a PC Card adapter and access it from FreeBSD, but even in this case, the card looks like a disk, not a memory card.

The original PC Card standard already has one foot in the grave: it’s a 16 bit bus that doesn't work well with modern laptops. The replacement standard has a 32 bit wide bus and is called CardBus.The cards look almost identical, and most modern laptops support both standards. In this book I'll use use the term PC Card to include CardBus unless otherwise stated. FreeBSD Release 5 includes completely new PC Card code. It now supports both 16 bit PC Card and 32 bit CardBus cards.

PC Card offers one concept that conventional cards don't: the cards are hot swappable. You can insert them and remove them in a running system. This poses a number of potential problems, some of which are only partially solved.

PC Card and CardBus both use the same form factor cards: they are 54 mm wide and at least 85 mm long, though some cards, noticeably wireless networking cards, are up to 120 mm long and project beyond the casing of the laptop. The wireless cards contain an antenna in the part of the card that projects from the machine.

PC Card cards can have one of three standard thicknesses:

• Type 1 cards are 3.3 mm thick. They're very uncommon.
• Type 2 cards are 5 mm thick. These are the most common type, and most laptops take two of them.
• Type 3 cards are 10.5 mm thick. In most laptops you can normally insert either one type 3 card or two type 2 cards.

The GENERIC FreeBSD kernel contains support for PC Card, so you don't need to build a new kernel.

The Universal Serial Bus (USB) is a new way of connecting external peripherals, typically those that used to be connected by serial or parallel ports. It's much faster than the old components: the old serial interface had a maximum speed of 115,200 bps, and the maximum you can expect to transfer over the parallel port is about 1 MB/s. By comparison, current USB implementations transfer data at up to 12 Mb/s, and a version with 480 Mb/s is in development.

As the name states, USB is a bus: you can connect multiple devices to a bus. Currently the most common devices are mid-speed devices such as printers and scanners, but you can connect just about anything, including keyboards, mice, Ethernet cards and mass storage devices.

A number of different disks have been used on PCs:

• ST-506 disks are the oldest. You can recognize them by the fact that they have two cables: a control cable that usually has connections for two disks, and a thinner data cable that is not shared with any other disk. They're just about completely obsolete by now, but FreeBSD Release 3 still supports them with the wd driver. These disks are sometimes called by their modulation format, Modified Frequency Modulation or MFM. A variant of MFM that offers about 50% more storage is RLL or Run Length Limited modulation. From the operating system point of view, there is no difference between MFM and RLL.
• ESDI (Enhanced Small Device Interface) disks were designed to work around some of the limitations of ST-506 drives. They also use the same cabling as ST-506, but they are not hardware compatible, though most ESDI controllers understand ST-506 commands. They are also obsolete, but the wd driver in FreeBSD Release 3 supports them, too.
• IDE (Integrated Device Electronics) , now frequently called ATA (AT Attachment) , is the current low-cost PC disk interface. It supports two disks connected by a single 40 or 80 conductor fat cable. The connectors for both cables are the same, but the 80 conductor cable is needed for the 66 MHz, 100 MHz and 133 MHz transfer rates supported by recent disk drives

  All modern IDE disks are so-called EIDE (Enhanced IDE) drives. The original IDE disks were limited by the PC BIOS standard to a size of 504 MB (1024 * 16 * 63 * 512, or 528,482,304 bytes). EIDE drives exceed this limit by several orders of magnitude

  A problem with older IDE controllers was that they used programmed I/O or PIO to perform the transfer. In this mode, the CPU is directly involved in the transfer to or from the disk. Older controllers transferred a byte at a time, but more modern controllers can transfer in units of 32 bits. Either way, disk transfers use a large amount of CPU time with programmed I/O, and it's difficult to achieve the transfer rates of modern IDE drives, which can be as high as 100 MB/s. During such transfers, the system appears to be unbearably slow: it " grinds to a halt. "

  To solve this problem, modern chipsets offer DMA transfers, which almost completely eliminate CPU overhead. There are two kinds of DMA, each with multiple possible transfer modes. The older DMA mode is no longer in use. It handled transfer rates between 2.1 MB/s and 16.7 MB/s. The newer UDMA (Ultra DMA) mode supports transfer rates between 16.7 MB/s and 133 MB/s. Current disks use UDMA33 (33 MHz transfer rate), which is the fastest rate you can use with a 40 conductor cable, and UDMA66 (66 MHz), UDMA100 (100 MHz) and UDMA-133 (133 MHz) with an 80 conductor cable. To get this transfer rate, both the disk and the disk controller must support the rate. FreeBSD supports all UDMA modes.

  Another factor influencing IDE performance is the fact that most IDE controllers and disks can only perform one transfer at a time. If you have two disks on a controller, and you want to access both, the controller serializes the requests so that a request to one drive completes before the other starts. This results in worse performance than on a SCSI chain, which does not have this restriction. If you have two disks and two controllers, it's better to put one disk on each controller. This situation is gradually changing, so when choosing hardware it's worth checking on current support for tagged queueing, which allows concurrent transfers.

• SCSI is the Small Computer Systems interface. It's usually pronounced "scuzzy." It is used for disks, tapes, CD-ROMs and also other devices such as scanners and printers. The SCSI controller is more correctly called a host adapter. LikeIDE, SCSI has evolved significantly overtime. SCSI devices are connected by a single fat cable, with 50 conductors (" narrow SCSI," which connects a total of 8 devices) or 68 conductors ("wide SCSI," which also connects up to 16 devices). Some SCSI devices have subdevices, for example CD-ROM changers.

  SCSI drives have a reputation for much higher performance than IDE. This is mainly because nearly all SCSI host adapters support DMA, whereas in the past IDE controllers usually used programmed I/O. In addition, SCSI host adapters can perform transfers from multiple units at the same time, whereas IDE controllers can only perform one transfer at a time. Typical SCSI drives are still faster than IDE drives, but the difference is nowhere near as large as it used to be. Narrow SCSI can support transfer rates of up to 40 MB/s (Ultra 2), and wide SCSI can support rates of up to 320 MB/s (Ultra 320). These speeds are not necessarily faster than IDE: you can connect more than seventies as many devices to a wide SCSI chain.

Before you install FreeBSD, you need to decide how you want to use the disk space available to you. If desired, FreeBSD can coexist with other operating systems on the Intel platform. In this section, we'll look at the way data is laid out on disk, and what we need to do to create FreeBSD file systems on disk.

The basics of disk drives are relatively straightforward: data is stored on one or more rotating disks with a magnetic coating similar in function to the coating on an audio tape. Unlike a tape, however, disk heads do not touch the surface: the rotating disk produces an air pressure against the head, which keeps it floating very close to the surface. The disk has (usually) one read/write head for each surface to transfer data to and from the system. People frequently talk about the number of heads, not the number of surfaces, though strictly speaking this is incorrect: if there are two heads per surface (to speed up access), you're still interested in the number of surfaces, not the number of heads.

While transferring data, the heads are stationary, so data is written on disks in a number of concentric circular tracks. Logically, each track is divided into a number of sectors, which nowadays almost invariably contain 512 bytes. A single positioning mechanism moves the heads from one track to another, so at any one time all the tracks under the current head position can be accessed without repositioning. This group of tracks is called a cylinder.

Since the diameter of the track differs from one track to the other, so does the storage capacity per track. Nevertheless, for the sake of simplicity, older drives, such as ST-506 (MFM and RLL) drives, had a fixed number of sectors per track. To perform a data transfer, you needed to tell the drive which cylinder, head and sector to address. This mode of addressing is thus called CHS addressing.

Modern disks have a varying number of sectors per track on different parts of the disk to optimize the storage space, and for the same reason they normally store data on the disk in much larger units than sectors. Externally, they translate the data into units of sectors, and they also optionally maintain the illusion of "tracks" and "heads," though the values have nothing to do with the internal organization of the disk. Nevertheless, BIOS setup routines still give you the option of specifying information about disk drives in terms of the numbers of cylinders, heads and sectors, and some insist on it. In reality, modern disk drives address sectors sequentially, so-called Logical Block Addressing or LBA. CHS addressing has an additional problem: various standards have limited the size of disks to 504 MB or 8 GB. We'll look at that in more detail on page 39.

SCSI drives are a different matter: the system BIOS normally doesn't know anything about them. They are always addressed in LBA mode. It's up to the host adapter to interrogate the drive and find out how much space is on it. Typically, the host adapter has a BIOS that interrogates the drive and finds its dimensions. The values it determines may not be correct: the PC BIOS 1 GB address limit (see page 39) might bite you. Check your host adapter documentation for details.

The PC BIOS divides the space on a disk into up to four partitions, headed by a partition table. For Microsoft systems, each partition may be either a primary partition that contains a file system (a "drive" in Microsoft terminology), or an extended partition that contains multiple file systems (or "logical partitions").

FreeBSD does not use the PC BIOS partition table directly. It maintains its own partitioning scheme with its own partition table. On the PC platform, it places this partition table in a single PC BIOS partition, rather in the same way that a PC BIOS extended partition contains multiple "logical partitions." It refers to PC BIOS partitions as "slices."

Partitioning offers the flexibility that other operating systems need, so it has been adopted by all operating systems that run on the PC platform. Figure 2-1 shows a disk with all four slices allocated. The Partition Table is the most important data structure. It contains information about the size, location and type of the slices (PC partitions). The PC BIOS allows one of these slices to be designated as active: at system startup time, its bootstrap record is used to start the system.

The partition table of a boot disk also contains a Master Boot Record (MBR), which is responsible for finding the correct slice and booting it. The MBR and the partition table take up the first sector on disk, and many people consider them to be the same thing. You only need an MBR on disks from which you boot the system.

PC usage designates at least one slice as the primary partition, the C: drive. Another slice may be designated as an extended partition that contains the other "drives" (all together in one slice).

UNIX systems have their own form of partitioning which predates the PC and is not compatible with the PC method. As a result, all versions of UNIX that can coexist with Microsoft implement their own partitioning within a single slice (PC BIOS partition). This is conceptually similar to an extended partition. FreeBSD systems define up to eight partitions per slice. They can be used for the following purposes:

• A partition can be a file system, a structure in which UNIX stores files.
• It can be used as a swap partition.FreeBSD uses virtual memory: the total addressed memory in the system can exceed the size of physical memory, so we need space on disk to store memory pages that don't fit into physical memory. Swap is a separate partition for performance reasons: you can use files for swap, like Microsoft does, but it is much less efficient.
• The partition may be used by other system components. For example, the Vinum volume manager uses special partitions as building blocks for volumes. We'll look at Vinum on page 221.
• The partition may not be a real partition at all. For example, partition c refers to the entire slice, so it overlaps all the rest. For obvious reasons, the partitions that represent file systems and swap space (a, b, and d through h) should not overlap.

Traditional UNIX treats disk devices in two different ways. As we have seen, you can think of a disk as a large number of sequential blocks of data. Looking at it like this doesn't give you a file system—it's more like treating it as a tape. UNIX calls this kind of access raw access. You'll also hear the term character device.

Normally, of course, you want files on your disk: you don't care where they are, you just want to be able to open them and manipulate them. In addition, for performance reasons the system keeps recently accessed data in a buffer cache. This involves a whole lot more work than raw devices. These devices are called block devices.

By contrast with UNIX, Linux originally did not have character disk devices. Starting with Release 4.0, FreeBSD has taken the opposite approach: there are now no user-accessible block devices anymore. There are a number of reasons for this:

• Having two different names for devices is confusing. In older releases of FreeBSD, you could recognize block and character devices in an ls -l listing by the letters b and c at the beginning of the permissions. For example, in FreeBSD 3.1 you might have seen:

  $ ls -l /dev/rwd0s1a /dev/wd0s1a
  crw-r----  1  root  operator   3,  131072  Oct  31  19:59  /dev/rwd0s1a
  brw-r----  1  root  operator   0,  131072  Oct  31  19:59  /dev/wd0s1a
  

  wd is the old name for the current ad disks. The question is: when do you use which one? Even compared to UNIX System V, the rules were different.

• Nearly all access to disk goes via the file system, and user-accessible block devices add complication.
• If you write to a block device, you don't automatically write to the disk, only into buffer cache. The system decides when to write to disk. If there's a problem writing to disk, there's no way to notify the program that performed the write: it might even already have finished. You can demonstrate this very effectively by comparing the way FreeBSD and Linux write to a floppy disk. It takes 50 seconds to write a complete floppy disk—the speed is determined by the hardware, so the FreeBSD copy program finishes after 50 seconds. With Linux, though, the program runs only for a second or two, after which it finishes and you get your prompt back. In the meantime, the system flushes the data to floppy: you still need to wait a total of 50 seconds. If you remove the floppy in this time, you obviously lose data.

The removal of block devices caused significant changes to device naming. In older releases of FreeBSD, the device name was the name of the block device, and the raw (character) device had the letter r at the beginning of the name, as shown in the example above.

Let's look more carefully at how BSD names its partitions:

• Like all other devices, the device nodes, the entries that describe the devices, are stored in the directory /dev.Unlike traditional UNIX and older releases of FreeBSD, FreeBSD Release 5 includes the device file system or devfs, which creates the device nodes automatically, so you don't need to worry about creating them yourself.
• Next comes the name of the driver. As we have seen, FreeBSD has drivers for IDE and friends (ad), SCSI disks (da) and floppy disks (fd). For SCSI disks, we now have the name /dev/da.
  The original releases of FreeBSD had the abbreviation wd for IDE drives. This abbreviation arose because the most popular of the original MFM controllers were made by Western Digital. Others claim, however, that it's an abbreviation for & Winchester Disk.& SCSI disks were originally abbreviated sd The name da comes from the CAM standard and is short for direct access. BSD/OS, NetBSD and OpenBSD still use the old names.
• Next comes the unit number, generally a single digit. For example, the first SCSI disk on the system would normally be called /dev/da0.
  Generally, the numbers are assigned during the boot probes, but you can reserve numbers for SCSI disks if you want. This prevents the removal of a single disk from changing the numbers of all subsequent drives. See page 575 for more details.
• Next comes the partition information. The so-called strict slice name is specified by adding the letter s (for slice) and the slice number (1 to 4) to the disk name. BSD systems name partitions by appending the letters a to h to the disk name. Thus, the first partition of the first slice of our disk above (which would typically be a root file system) would be called /dev/da0s1a.

  Some other versions of BSD do not have the same support for slices, so they use a simpler terminology for the partition name. Instead of calling the root file system /dev/da0s1a, they refer to it as /dev/da0a. FreeBSD supports this method as well— it's called compatibility slice naming. The compatibility slice is simply the first FreeBSD slice found on the disk, and the partitions in this slice have two different names, for example /dev/ad0s1a and /dev/ad0a.

• Partition c is an exception: by convention, it represents the whole BSD disk (in this case, the slice in which FreeBSD resides).
• In addition, NetBSD reserves partition d for the entire disk, including other partitions. FreeBSD no longer assigns any special signifycance to partition d.

Figure 2-2 shows a typical layout on a system with a single SCSI disk, shared between Microsoft and FreeBSD. You'll note that partition /dev/da0s3c is missing from the FreeBSD slice, since it isn't a real partition. Like the PC BIOS partition table, the disk label contains information necessary for FreeBSD to manage the FreeBSD slice, such as the location and the lengths of the individual partitions. The bootstrap is used to load the kernel into memory. We’ll look at the boot process in more detail in Chapter 29 .

Table 2-1 gives you an overview of the devices that FreeBSD defines for this disk.

Armed with this knowledge, we can now proceed to make some decisions about how to install our systems. First, we need to answer some questions:

• Do we want to share this disk with any other operating system?
• If so, do we have data on this disk that we want to keep?

If you already have another system installed on the disk, it is best to use that system's tools for manipulating the partition table. FreeBSD does not normally have difficulty with partition tables created by other systems, so you can be reasonably sure that the other system will understand what it has left. If the other system is Microsoft, and you have a slice that you don't need, use the MS-DOS FDISK program to free up enough space to install FreeBSD. If you don't have a slice to delete, you can use the FIPS program to create one—see Chapter 5 , Installing FreeBSD, page 52.

If for some reason you can't use MS-DOS FDISK, for example because you're installing FreeBSD by itself, FreeBSD also supplies a program called fdisk that manipulates the partition table. Normally you invoke it indirectly via the sysinstall program—see page 63.

Disk storage capacity has grown by several orders of magnitude since FreeBSD was first released. As it did so, a number of limits became apparent:

• The first was the BIOS 504MB limit on IDE disks, imposed by their similarity with ST-506 disks. We discussed this on page 32. FreeBSD works around this issue by using a loader that understands large disks, so this limit is a thing of the past.
• The next limit was the 1 GB limit, which affected some older SCSI host adapters. Although SCSI drives always use LBA addressing internally, the BIOS needed to simulate CHS addressing for Microsoft. Early BIOSes were limited to 64 heads, 32 sectors and 1024 tracks (64 x 32 x 1024 x 512 = 1 GB). This wouldn't be such a problem, except that some old Adaptec controllers offer a 1 GB compatibility option. Don't use it: it's only needed for systems that were installed with the old mapping.
• After that, it's logical that the next limit should come at 2 GB. There are several different problems here. The only one that affects FreeBSD appears to be a bug in some IDE controllers, which don't work beyond this limit. All of them are old, and IDE controllers don't cost anything, so if you are sure you have this problem, you can solve it by replacing the controller. Make sure you get one that supports DMA

  Other systems, including many versions of UNIX System V, have problems with this limit because is the largest number that can be represented in a 32 bit signed integer. FreeBSD does not have this limitation, as file sizes are represented in 64 bit quantities.

• At 4 GB, some IDE controllers have problems because they convert this to a CHS mapping with 256 heads, which doesn't work: the largest number is 255. Again, if you're sure this is the cause of problems you may be having, a new controller can help.
• At 8 GB the CHS system runs out of steam. It can't describe more than 1024 cylinders, 255 heads or 63 sectors. Beyond this size, you must use LBA addressing if your BIOS supports it.
• You'd expect more problems at 16 GB, but in fact the next limitation doesn't come until 128 GB. It's due to the limitations in the original LBA scheme, which had only 28 bits of sector address. The new standard extends this to 48 bits, which should be sufficient for the next few years. FreeBSD already uses the new standard, so this limitation has never been an issue.

None of these problems affect FreeBSD directly. The FreeBSD bootstrap no longer uses the system BIOS, so it is not bound by the restrictions of the BIOS and the controller. If you use another operating system's loader, however, you could have problems. If you have the choice, use LBA addressing. Unfortunately, you can't do so if the disk already contains software that uses CHS addressing.

Other things to consider are:

• If you have other software already installed on the disk, and you want to keep it, do not change the drive geometry. If you do so, you will no longer be able to run the other software.
• Use LBA addressing if your hardware supports it.
• If you have to use CHS, and you don't have any other software on the drive, use the drive geometry specified on the disk itself or in the manual, if you're lucky enough to get a manual with the disk. Many BIOSes remap the drive geometry in order to get Microsoft to agree to work with the disk, but this can break FreeBSD disk mapping. Check that the partition editor has these values, and change them if necessary.
• If all else fails, install Microsoft in a small slice at the start of the disk. This creates a valid partition table for the drive, and the installation software understands it. Once you have started the installation process, the Microsoft partition has fulfilled its purpose, and you can delete it again.

For years, UNIX users have worked with a single 80x25 character mode display. Many people consider this extremely old-fashioned, but in fact the flexibility of the UNIX system made this quite a good way to work. Still, there's no doubt of the advantage of a system that offers the possibility of performing multiple operations at once, and this is one of the particular advantages of UNIX. But you normally need a terminal to interact with each task. The best way to do this is with the X Window System. You might also want to use a desktop, a set of programs that offer commonly used functionality.

In many other environments, the GUI and the graphical display are the same thing, and in some systems, notably Microsoft, there is no clear distinction between the operating system and the GUI. In UNIX, there are at least four levels of abstraction:

• The kernel runs the computer.
• X interfaces with the kernel and runs the display. It doesn't display anything itself except possibly a display background, by default a grey cross-hatch pattern.
• The window manager gives you control over the windows, such as moving, resizing and iconification (often called minimizing in other systems). It provides the windows with decorations like frames, buttons and menus.
• The desktop provides commonly used applications and ways of starting them. Many people get by without a desktop by using window manager functionality.

Why do it this way? Because it gives you more choice. There are dozens of window managers available, and also several desktops. You're not locked in to a single product. This has its down side, though: you must make the choice, and so setting up X requires a little more thought than installing Microsoft.

X runs on almost any hardware. That doesn't mean that all hardware is equal, of course. Here are some considerations:

X uses the keyboard a lot more than Microsoft. Make sure you get a good one.

X prefers a three-button mouse, though it has provisions for up to five buttons. It can support newer mice with rollers and side buttons, but most software does not use them. Some mice, such as the Logitech wireless mouse, require undocumented sequences to enable some buttons (the thumb button in the case of Logitech). X does not support this button.

Get the best mouse you can. Prefer a short, light switch. It must have at least three buttons. Accept no substitutes. Look for one with an easy-to-use middle button. Frequently mice with both a middle button and a roller make it difficult to use the middle button: it's either misplaced, too heavy in action, or requires pressing on the roller (and thus possibly turning it). All of these prove to be a nuisance over time.

Older mice connected via the serial port or a special card (&bus mouse&). Nowadays most mice are so-called PS/2 mice, and USB mice are becoming more popular.

X enables you to do a lot more in parallel than other windowing environments. As a result, screen real estate is at a premium. Use as big a monitor as you can afford, and as high a resolution as your monitor can handle. You should be able to display a resolution of 1600x1200 on a 21" monitor, 1280x1024 on a 17" monitor, and 1024x768 on a 14" monitor. Premium quality 21" monitors can display 2048x1536. If that’s not enough, we'll look at multiple monitor configurations on page 523.

If you have a laptop, you don't get any choice. The display has a native resolution which you can't change. Most laptops display lower resolutions by interpolation, but the result looks much worse than the native resolution. LCD screens look crisper than CRT monitors, so you can choose higher resolutions modern laptops have display resolutions of up to 1600x1200.

If you're going to use your laptop for presentations with overhead projectors, make sure you find one that can display both on the internal screen and also on the external output at the same time, while maintaining a display resolution of 1024x768: not many over head projectors can display at a higher resolution.

FreeBSD also supports computers based on the Compaq (previously Digital) AXP processor, commonly called Alpha. Much of the information above also applies to the Alpha; notable exceptions are:

• Much of the PC hardware mentioned above was never supplied with the Alpha. This applies particularly to older hardware.
• The PC BIOS is very different from the Alpha console firmware. We'll look at that below.
• Disk partitioning is different. FreeBSD does not support multiple operating systems on the Alpha platform.

In this section we'll look at some additional topics that only apply to the Alpha.

FreeBSD requires the SRM console firmware, which is used by Tru64 (formerly known as Digital UNIX). It does not work with the ARC firmware (sometimes called AlphaBIOS) used with Microsoft NT. The SRM firmware runs the machine in 64 bit mode, which is required to run FreeBSD, while the ARC firmware sets 32 bit mode. If your system is currently running Tru64, you should be able to use the existing SRM console.

The SRM console commands differ from one version to another. The commands supported by your version are described in the hardware manual that was shipped with your system. The console help command lists all supported console commands. If your system

has been set to boot automatically, you must type Ctrl-C to interrupt the boot process and get to the SRM console prompt (>>>). If the system is not set to boot automatically, it displays the SRM console prompt after performing system checks.

All SRM console versions support the set and show commands, which operate on environment variables that are stored in non-volatile memory. The show command lists all environment variables, including those that are read-only.

Alpha's SRM is picky about which hardware it supports. For example, it recognizes NCR SCSI boards, but it doesn't recognize Adaptec boards. There are reports of some Alphas not booting with particular video boards. The GENERIC kernel configuration (/usr/src/sys/alpha/conf/GENERIC) shows what the kernel supports, but that doesn't mean that the SRM supports all the devices. In addition, the SRM support varies from one machine to the next, so there's a danger that what's described here won't work for you.

Other differences for Alpha include:

• The disk layout for SRM is different from the layout for Microsoft NT. SRM looks for its bootstrap where Microsoft keeps its partition table. This means that you cannot share a disk between FreeBSD and Microsoft on an Alpha.
• Most SRM-based Alpha machines don't support IDE drives: you're limited to SCSI.

The easiest way to install FreeBSD is from CD-ROM. You can buy them at a discount with the order form at the back of the book, or you can download an ISO image from ftp://ftp.FreeBSD.org and create your own CD-ROM. There are a number of CD-ROMs in a FreeBSD distribution, but the only essential one is the first one, the Installation CD-ROM. It contains everything you need to install the system itself. The other CD-ROMs contain mainly installable packages. Individual releases may contain other data, such as a copy of the source code repository. We'll take a more detailed look at the installation CD-ROM here.

The Installation CD-ROM contains everything you need to install FreeBSD on your system. It supplies two categories of installable software:

• The base operating system is stored as gzipped tar archives in the directories base, boot, cat pages, compat1x, compat20, compat21, compat3x, compat4x, des, dict, doc, games, info, manpages and proflibs.To facilitate transport to and installation from floppy, the archive shave been divided into chunks of 1.44 MB. For example, the only required set is in the files base/base.?? , in other words, all files whose names start with base. and contain two additional characters. This specifically excludes the files base.inf and base.mtree, which are not part of the archive.
• The directory packages/All contains ported, installable software packages as gzipped tar archives. They are designed to be installed directly on a running system, so they have not been divided into chunks. Due to size restrictions on the CD-ROM, this directory does not contain all the packages: others are on additional CD-ROMs.

packages/Latest contains the latest versions of the packages.

packages/All contains a large subset of the Ports Collection. To make it easier for you to find your way around them, symbolic links to appropriate packages have been placed in the directories archivers, astro, audio, benchmarks, biology, cad, chinese, comms, converters, databases, deskutils, devel, editors, emulators, french, ftp, games, german, graphics, hebrew, irc, japanese, java, korean, lang, mail, math, mbone, misc, net, news, palm, picobsd, plan9, print, russian, science, security, shells, sysutils, templates, textproc, ukrainian, vietnamese, www, x11, x11-clocks, x11-fm, x11-fonts, x11-servers, x11-toolkits and x11-wm. Don't get the impression that these are different packages—they are really pointers to the packages in All. You will find a list of the currently available packages in the file packages/INDEX.

We'll look at the Ports Collection in more detail in Chapter 9.

The .TXT files are also supplied in HTML format with a .HTM suffix.

The contents of the CD-ROM will almost certainly change from one release to another. Read README.TXT for details of the changes.

Although the installation CD-ROM contains everything you need to install FreeBSD, the format isn't what you'd like to handle every day. The distribution may include a Live File System CD-ROM, which solves this problem: it contains substantially the same data stored in file system format in much the same way as you would install it on a hard disk. You can access the files directly from this CD-ROM.

One of the disks may also contain the &CVS Repository.&The repository is the master source tree of all source code, including all update information. We'll look at it in more detail in Chapter 31 , Keeping up to date,page 581.

An important part of FreeBSD is the Ports Collection, which comprises many housand popular programs. The Ports Collection automates the process of porting software to FreeBSD. A combination of various programming tools already available in the base FreeBSD installation allows you to simply type make to install a given package. The ports mechanism does the rest, so you need only enough disk space to build the ports you want. We'll look at the Ports Collection in more detail in Chapter 9 . The files are spread over a number of CD-ROMs:

• You'll find the ports, the instructions for building the packages, on the installation CD-ROM
• The base sources for the Ports Collection fill more than one CD-ROM, even though copyright restrictions mean that not all sources may be included: some source files are freely distributable on the Net, but may not be distributed on CD-ROM.
• Don't worry about the missing sources: if you're connected to the Internet, the Ports Collection automatically retrieves the sources from an Internet server when you typemake.
• You'll find the most popular packages, the precompiled binaries of the ports, on the Installation CD-ROM. A full distribution contains a number of other CD-ROMs with most of the remaining packages.

In Chapters 4 to 6 we'll go into a lot of detail about how to install the system. Maybe this is too much detail for you. If you're an experienced UNIX user, you should be able to get by with significantly less reading. This chapter presents checklists for some of the more usual kinds of installation. Each refers you to the corresponding detailed descriptions in Chapters 4 through 6.

On the following pages we'll look at the simplest installation, where FreeBSD is the only system on the disk. Starting on page 49 we'll look at sharing the disk with Microsoft, and on page 50 we'll look at how to install XFree86. You may find it convenient to photo copy these pages and to mark them up as you go along.

It is probably easier to install FreeBSD than any other PC operating system, including Microsoft products. Well, most of the time, any way. Some people spend days trying to install FreeBSD, and finally give up. That happens with Microsoft's products as well, but unfortunately it happens more often with FreeBSD.

Now you're probably saying, "That doesn't make sense. First you say it's easier to install, then you say it's more likely to fail. What's the real story?"

As you might expect, the real story is quite involved. In Chapter 2, Before you install, I went into some of the background. Before you start, let's look at what you can do to make the installation as easy as possible:

• Use known, established hardware. New hardware products frequently have undocumented problems. You can be sure that they work under Microsoft, because the manufacturer has tested them in that environment. In all probability, he hasn’t tested them under any flavour of UNIX, let alone FreeBSD. Usually the problems aren't serious, and the FreeBSD team solves them pretty quickly, but if you get the hardware before the software is ready, you’re the guinea pig.
• At the other end of the scale, you can have more trouble with old hardware as well. It's not as easy to configure, and old hardware is not as well supported as more recent hardware.
• Perform a standard installation. The easiest way to install FreeBSD is by booting from a CD-ROM and installing on an empty hard disk from the CD-ROM. If you proceed as discussed in Chapter 5, Installing FreeBSD, you shouldn't have any difficulty.
• If you need to share your hard disk with another operating system, it's easier to install both systems from scratch. If you do already have a Microsoft system on the disk, you can use FIPS (see page 52) to make space for it, but this requires more care.
• If you run into trouble, RTFM. I've gone to a lot of trouble to anticipate the problems you might encounter, and there's a good chance that you will find something here to help.
• If you do all this, and it still doesn't work, see page 17 for ways of getting external help.

This procedure applies if you can install FreeBSD without first having to make space on disk. Perform the following steps:

• Boot from CD-ROM. Most systems support booting from CD-ROM, but if yours doesn't:
  • Create two boot floppies by copying the images /cdrom/fbppies/kern.ftp and /cdrom/fbppies/mfsroot.ftp to 3,5" diskettes. Refer to page 89 for more details.
  • Insert the CD-ROM in the drive before booting.
  • Boot from the kern.flp floppy. After loading, insert the mfsroot.flp floppy when the system prompts you to do so, then press Enter.
    If you have a larger floppy, such as 2.88 MB or LS-120, you can copythe image /cdrom/floppies/boot.fp to it and boot from it. In this case you don't need to change disks.
• Select the Custom installation. Refer to page 60.
• What you do in the partition editor depends on whether you want to share the drive with another operating system or not:
  • If you want to use the drive only for FreeBSD, delete any existing slices, and allocate a single FreeBSD slice that takes up the entire disk. On exiting from the partition editor, select the Standard MBR. Refer to page 66.
  • If you want to share the disk with other systems, delete any unwanted slices and use them for FreeBSD. On exiting from the partition editor, select the BootMgr MBR. Refer to page 66.
• In the disk label editor, delete any existing UNIX partitions. Create the file systems manually. If you don't have any favourite layout, create a root file system with 4 GB, a swap partition with at least 512 MB (make sure it's atleast 1 MB larger than the maximum memory you intend to install in your system). Allocate a /home file system as large as you like, as long as it can fit on a single tape when backed up. If you have any additional space, leave it empty unless you know what to use it for. See page 68 for the rationale of this approach, which is not what sysinstall recommends.
• Install the complete system, including X and the Ports Collection. This requires about 1 GB of disk space. Refer to page 75 if you want to limit it.
• Select CD-ROM as installation medium. Refer to page 76.
• Give final confirmation. The system will be installed. Refer to page 77.
• After installation, set up at least a user ID for yourself. Refer to page 144.

If you have a disk with Microsoft installed on only part of the disk, and you don't want to change the partition layout, you can proceed as in the instructions above. This is pretty unusual, though: normally Microsoft takes the whole disk, and it's difficult to persuade it otherwise. To install FreeBSD on a disk that currently contains a single Microsoft partition taking up the entire disk, go through the following steps:

• Make a backup! There's every possibility of erasing your data, and there's absolutely no reason why you should take the risk.
• If you have an old machine with an IDE disk larger than 504 MB, you may run into problems. Refer to page 32 for further details.
• Boot Microsoft and repartition your disk with FIPS. Refer to page 52.
• Insert the CD-ROM in the drive before booting.
• Shut the machine down and reboot from the FreeBSD CD-ROM. If you have to boot from floppy, see page 48 for details.
• Select the Custom installation.
• In the partition editor, delete only the second primary Microsoft partition. The first primary Microsoft partition contains your Microsoft data, and if there is an extended Microsoft partition, it will also contain your Microsoft data.
• Create a FreeBSD slice in the space that has been freed. Refer to page 63.
• On exiting from the partition editor, select the BootMgr MBR. Refer to page 66.
• In the disk label editor, delete any existing UNIX partitions. Create the file systems manually. If you don't have any favourite layout, create a root file system with 4 GB, a swap partition with at least 512 MB (make sure it's at least 1 MB larger than the maximum memory you intend to install in your system). Allocate a /home file system as large as you like, as long as it can fit on a single tape when backed up. If you have any additional space, leave it empty unless you know what to use it for. See page 68 for the rationale of this approach, which is not what sysinstall recommends.
• Before leaving the disk label editor, also select mount points for your DOS partitions if you intend to mount them under FreeBSD. Refer to page 74.
• Install the complete system, including X and the Ports Collection. This requires about 1 GB of disk space. Refer to page 75 if you want to limit it.
• Select CD-ROM as installation medium. Refer to page 76.
• Give final confirmation. The system will be installed. Refer to page 77.
• After installation, set up at least a user ID for yourself. Refer to page 144.

• You can configure XFree86 during installation or after reboot.
• Make sure your mouse is connected to the system at boot time. Depending on the hardware, if you connect it later, it may not be recognized.
• If you have already rebooted the machine, log in as root and restart sysinstall.
• Select the sys install Configuration menu, XFree86 and then xf86cfg, and follow the instructions. See page 102 for further details.
• Select the Desktop menu and install the window manager of your choice. See page 108 for further discussion.

In many cases, you won't want to install FreeBSD on the system by itself: you may need to use other operating systems as well. In this chapter, we’ll look at what you need to do to prepare for such an installation. If you're only running FreeBSD on the machine, you don't need to read this chapter, and you can move onto Chapter 5, Installing FreeBSD.

Before you start the installation, read this chapter carefully. It's easy to make a mistake, and one of the most frequent results of mistakes is the total loss of all data on the hard disk.

Currently, only the ia32 (Intel) port of FreeBSD is capable of sharing with other operating systems. We'll concentrate on how to share your system with Microsoft, because that's both the most difficult and the most common, but most of this chapter applies to other operating systems as well. You may want to refer to the discussion of Microsoft and FreeBSD disk layouts on page 34.

The first question is: do you need to share a disk between FreeBSD and the other operating system? It's much easier if you don't have to. In this section, we'll look at what you need to do.

Many operating systems will only boot from the first disk identified by the BIOS, usually called the C: disk in deference to Microsoft. FreeBSD doesn't have this problem, so the easiest thing is to install FreeBSD on the entire second disk. BIOS restrictions usually make it difficult to boot from any but the first two disks.

In this case, you don't really need to do anything special, although it's always a good idea to back up your data first. Install FreeBSD on the second disk, and choose the Boot Manager option in the partition editor (page 64). This will then give you the choice of booting from the first or second disk. Note that you should not change the order of disks after such an installation; if you do, the system will not be able to find its file systems after boot.

If you intend to share a disk between FreeBSD and another operating system, the first question is: is there enough space on the disk for FreeBSD? How much you need depends on what you want to do with FreeBSD, of course, but for the sake of example we'll take 120 MB as an absolute minimum. In the following section, we'll consider what to do if you need to change your partitions. If you already have enough space for a FreeBSD partition (for example, if you have just installed Microsoft specifically for sharing with FreeBSD, and thus have not filled up the disk), continue reading on page 66.

Sharing with other free operating systems is relatively simple. You still need to have space for FreeBSD, of course, and unlike Microsoft, there are no tools for shrinking Linux or BSD file systems: you'll have to remove them or recreate them. You can find some information about sharing with Linux in the mini-Howto at http://wwwlinux.org/docs/ldp/howto/mini/Linux+FreeBSD.html.

NetBSD and Open BSD file systems and slices are very similar to their FreeBSD counterparts. They're not identical, however, and you may find that one of the systems recognizes the partition of another system and complains about it because it's not quite right. For example, NetBSD has a d partition that can go outside the boundary of the slice. FreeBSD does not allow this, so you get a harmless error message.

Typically, if you've been running Microsoft on your machine, it will occupy the entire disk. If you need all this space, of course, there's no way to install another operating system as well. Frequently, though, you'll find that you have enough free space in the partition. Unfortunately, that’s not where you want it: you want the space in a new partition. There are a number of ways to do so:

• You can reinstall the software. This approach is common in the Microsoft world, but FreeBSD users try to avoid it.
• You can use FIPS to shrink a Microsoft partition, leaving space for FreeBSD. FIPS is a public domain utility, and it is included on the FreeBSD CD-ROM.
• If you can't use FIPS, use a commercial utility like PartitionMagic.This is not included on the CD-ROMs, and we won't discuss it further.

In the rest of the section, we'll look at how to shrink a partition with FIPS. If you do it with PartitionMagic, the details are different, but the principles are the same. In particular:

Before repartitioning your disk, make a backup. You can shoot yourself in the foot with this method, and the result will almost invariably be loss of data.

If you've been running Microsoft on your system for any length of time, the data in the partition will be spread all around the partition. If you just truncate the partition, you'll lose a lot of data, so you first need to move all the data to the beginning of the partition. Do this with the Microsoft defragmentation utility. Before proceeding, consider a few gotchas:

• The new Microsoft partition needs to be big enough to hold not only the current data, but also anything you will want to put in it in the future. If you make it exactly the current size of the data, it will effectively be full, and you won't beable to write anything to it.
• The second partition is also a Microsoft partition. To install FreeBSD on it, you need to convert it into a FreeBSD partition.
• FIPS may result in configuration problems with your Microsoft machine. Since it adds a partition, any automatically assigned partitions that followwill have a different drive letter. In particular, this could mean that your CD-ROM drive will ''move.'' After you delete the second Microsoft partition and change it into a FreeBSD partition, it will ''move'' back again.

For further information, read the FIPS documentation in /cdrom/tools/fips.doc. In particular, note these limitations:

• FIPS works only with Hard Disk BIOSes that use interrupt 0x13 for low-level hard disk access. This is generally not a problem.
• FIPS does not split partitions with 12 bit FATs, which were used by older versions of Microsoft. These are less than 10 MB in size and thus too small to be worth splitting.
• FIPS splits only Microsoft partitions. The partition table and boot sector must conform to the MS-DOS 3.0+ or Windows 95 conventions. This is marked by the system indicator byte in the partition table, which must have the value 4 (16 bit sector number) or 6 (32 bit sector number). In particular, it will not split Linux or Windows 2000 and later partitions.
• FIPS does not yet work on extended Microsoft partitions.
• FIPS needs a free partition entry. It will not work if you already have four partitions.
• FIPS will not reduce the original partition to a size of less than 4085 clusters, because this would involve rewriting the 16 bit FAT to a 12 bit FAT.

In this section, we'll go through the mechanics of repartitioning a disk. We'll start with a disk containing a single, complete Microsoft system.

First, run the Microsoft error check utility on the partition you want to split. Make sure no "dead" clusters remain on the disk.

Next, prepare a bootable floppy. When you start FIPS, you will be given the opportunity to write backup copies of your root and boot sector to a file on drive A:. These will be called ROOTBOOT.00x, where x represents a digit from 0 to 9. If anything goes wrong while using FIPS, you can restore the original configuration by booting from the floppy and running RESTORRB.

Before starting FIPS you must defragment your disk to ensure that the space to be used for the new partition is free. If you're using programs like IMAGE or MIRROR, note that they store a hidden system file with a pointer to your mirror files in the last sector of the hard disk. You must delete this file before using FIPS. It will be recreated the next time you run MIRROR. To delete it, in the root directory enter:

C\:> attrib -r -s -h image.idx  for IMAGE
C\:> attrib -r -s -h mirorsav.fil  for MIRROR

Then delete the file.

If FIPS does not offer as much disk space for creation of the new partition as you expect, this may mean that:

• You still have too much data in the remaining partition. Consider making the new partition smaller or deleting some of the data. If you delete data, you must defragment and run FIPS again.
• There are hidden files in the space of the new partition that have not been moved by the defragmentation program. Make sure which program they belong to. If a file is a swap file of some program (for example NDOS) it is possible that it can be safely deleted (and will be recreated automatically later when the need arises). See your manual for details.
• If the file belongs to some sort of copy protection, you must uninstall the program to which it belongs and reinstall it after repartitioning.

If you are running early versions of MS-DOS (before 5.0), or another operating system, such as OS/2, or you are using programs like Stacker, SuperStor, or Doublespace, read the FIPS documentation for other possible problems.

After defragmenting your Microsoft partition, you can run FIPS:

C:\> D:             changetoCD-ROM
D:\> cd \tools      Make sure you're in the tools directory
D:\tools\> fips     and start the FIPS program
... a lot of copyright information omitted 
Press any key              do what the computer says
Which Drive (1=0x80/2=0x81)?

The message Which Drive may seem confusing. It refers to BIOS internal numbering. Don't worry about it: if you want to partition the first physical drive inthe system, (C:), enter 1, otherwise enter 2. Like the BIOS, FIPS handles only two hard disks.

If you start FIPS under Windows, it will complain and tell you to boot from a floppy disk. It won't stop you from continuing, but it is a Bad Idea to do so.

Next, FIPS reads the root sector of the hard disk and displays the partition table:

This shows that only the first partition is occupied, that it is bootable, and that it occupies the whole disk (19571 MB, from Cylinder 0, Head 1, Sector 1 to Cylinder 2047, Head 238, Sector 63). It also claims that this makes 40083057 sectors. It doesn't: the cylinder number has been truncated, and FIPS complains about a partition table inconsistency, which it fixes. After this, we have:

Don't worry about the "bootable" flag here—we'll deal with that in the FreeBSD installation. First, FIPS does some error checking and then reads and displays the boot sector of the partition:

Checking boot sector ... OK
Press any Key                  do what it says
Bytes per sector: 512
Sectors per cluster: 32
Reserved sectors: 32
Number of FATs: 2
Number of rootdirectory entries: 0
Number of sectors (short): 0
Media descriptor byte: f8h
Sectors per FAT: 9784
Sectors per track: 63
Drive heads: 240
Hidden sectors: 63
Number of sectors (long): 40083057
Physical drive number: 80h
Signature: 29h

After further checking, FIPS asks you if you want to make a backup floppy. Enter your formatted floppy in drive A: and makethe backup. Next, you see:

Enter start cylinder for new partition (35 - 2650):
Use the cursor keys to choose the cylinder, <enter> to continue
Old partition  Cylinder  New Partition
  258.4 MB        35       19313.4 MB

Use the Cursor Left and Cursor Right keys to adjust the cylinder number at which the new partition starts. You can also use the keys Cursor Up and Cursor Down to change in steps of ten cylinders. FIPS updates the bottom line of the display to show the new values selected. Initially, FIPS chooses the smallest possible Microsoft partition, so initially you can only increase the size of the old partition (with the Cursor Right key). When you're happy with the sizes, press Enter to move on to the next step.

In this example, we choose equal-sized partitions:

To ensure that the partition is recognized, reboot immediately. Make sure to disable all programs that write to your disk in CONFIG.SYS and AUTOEXEC.BAT before rebooting. It might be easier to to rename the files or to boot from floppy. Be particularly careful to disable programs like MIRROR and IMAGE, which might get confused if the partitioning is not to their liking. After rebooting, use CHKDSK or Norton Disk Doctor to make sure the first partition is OK. If you don't find any errors, you may now reboot with your normal CONFIG.SYS and AUTOEXEC.BAT. Start some programs and make sure you can still read your data.

After that, you have two valid Microsoft partitions on your disk. We'll look at what to do with them in the next chapter. The specific differences from a dedicated install are on page 66, but you'll need to start from the beginning of the chapter to do the install.

In the previous chapters, we've looked at preparing to install FreeBSD. In this chapter, we'll finally do it. If you run into trouble, I'll refer you back to the page of Chapter 2 which discusses this topic. If you want to install FreeBSD on the same disk as Microsoft or another operating system, you should have already read Chapter 4 , Shared OS installation.

The following discussion relates primarily to installation on the i386 architecture. See page 78 for differences when installing on the AXP ("Alpha") processor.

To install FreeBSD you need the software in a form that the installation software understands. You may also need a boot diskette. Nowadays you will almost invariably install from CD-ROM, so we'll assume that medium. On page 85, we'll look at some alternatives: installation from floppy disk or via the network.

The first step in installing FreeBSD is to start a minimal version of the operating system. The simplest way is to boot directly from the installation CD-ROM. If your system doesn't support this kind of boot, boot from floppy. See page 85 for more details.

The description in this chapter is based on a real-life installation on a real machine. When you install FreeBSD on your machine, a number of things will be different, depending on the hardware you're running, the way you're installing the software and the release of FreeBSD you're installing. Nevertheless, you should be able to recognize what is going on.

Booting from CD-ROM is mainly a matter of setting up your system BIOS and possibly your SCSI BIOS. Typically, you perform one of the following procedures:

• If you're booting from an IDE CD-ROM, you enter your system BIOS setup routines and set the Boot sequence parameter to select CD-ROM booting ahead of hard disk booting, and possibly also ahead of floppy disk booting. A typical sequence might be CDROM,C,A
• On most machines, if you're booting from a SCSI CD-ROM, you also need a host adapter that supports CD-ROM boot. Set up the system BIOS to boot in the sequence, say, SCSl, A, C. On typical host adapters (such as the Adaptec 2940 series), you set the adapter to enable CD-ROM booting, and set the ID of the boot device to the ID of the CD-ROM drive.

These settings are probably not what you want to use for normal operation. If you leave the settings like this, and there is a bootable CD-ROM in your CD-ROM drive, it always boots from that CD-ROM rather than from the hard disk. After installation, change the parameters back again to boot from hard disk before CD-ROM. See your system documentation for further details.

The boot process itself is very similar to the normal boot process described on page 528. After it completes, though, you are put into the sysinstall main menu.

Figure 5-1 shows the main sysinstall menu. sysinstall includes online help at all stages. Simply press F1 and you will get appropriate help. Also, if you haven't been here before, the Doc menu gives you a large part of the appropriate information from the handbook.

To get started, select one of Standard, Express or Custom.The names imply that the Standard installation is the best way to go, the Express installation is for people in a hurry, and Custom installation is for when you want to specify exactly what is to be done.

In fact, the names are somewhat misleading. There isn't really that much difference between the three forms of installation. They all perform the same steps:

• Possibly set up options.
• Set up disk partitions, which we'll discuss in the next section.
• Set up file systems and swap space within a FreeBSD slice, which we start on page 67.
• Choose what you want to install, which we discuss on page 75.
• Choose where you want to install it from. We'll look at this on page 76.
• Actually install the software. We'll treat this on page 77.

We looked at disk partitions and file systems on page 34. We'll look at the other points when we get to them. So what's the difference between the kinds of installation?

• The Standard installation takes you through these steps in sequence. Between each step, you get a pop-up window that tells you what is going to happen next.
• The Express installation also takes you through these steps in sequence. The main difference is that you don't get the pop-up window telling you what is going to happen next. This can save a little time. If you do want the information, similar information is available with the F1 key.
• The Custom installation returns you to its main menu after each step. It's up to you to select the next step. You can also select another step, or go back to a previous one. Like the Express installation, you don't get the pop-up information window, but you can get more information with the F1 key.

The big problem with Standard and Express installations is that they don't let you back up: if you pass a specific step and discover you want to change something, you have to abort the installation and start again. With the Custom installation, you can simply go back and change it. As a result, I recommend the Custom installation. In the following discussion, you won't see too much difference: the menus are the same for all three installation forms.

The first item on the menu is to set installation options. There's probably not too much you'll want to change. About the only thing of interest might be the editor ec, which is a compromise between a simple editor for beginners and more complicated editors like vi. If you're planning to edit anything during the installation, for example the file /etc/exports , which we'll look at on page 566, you may prefer to set an editor with which you are familiar. Select the fields by moving the cursor to the line and pressing the space bar.

The first installation step is to set up space for FreeBSD on the disk. We looked at the technical background in Chapter 2, on page 39. In this section only, we’ll use the term partition to refer to a slice or BIOS partition, because that's the usual terminology.

Even if your disk is correctly partitioned, select the Partition menu: the installation routines need to enter this screen in order to read the partition information from the disk. If you like what you see, you can leave again immediately with q (quit), but you must first enter this menu. If you have more than one disk connected to your machine, you will next be asked to choose the drives that you want to use for FreeBSD.

#isDisk selection menu

This screen shows entries for each drive that sysinstall has detected; in this example, the system has one ATA (IDE) drive, /dev/ad0, and one SCSI drive, Dao. You only get this screen if you have at least two drives connected to your machine; otherwise sysinstall automatically goes to the next screen.

If you intend to use more than one disk for FreeBSD, you have the choice of setting up all disks now, or setting the others up after the system is up and running. We'll look at the latter option in Chapter 11 , on page 199.

To select the disk on which you want to install FreeBSD, move the cursor to the appropriate line and press the space bar. The screen you get will probably look like Figure 5-5. Table 5-1 explains the meanings of the columns in this display. The first partition contains the Master Boot Record, which is exactly one sector long, and the bootstrap, which can be up to 15 sectors long. The partitioning tools use the complete first track: in this case, the geometry information from BIOS says that it has 63 sectors per track.

In this case, the Microsoft file system uses up the whole disk except for the last track, 1008 sectors (504 kB) at the end of the disk. Clearly there's not much left to share. We have the option of removing the Microsoft partition, which we'll look at here, or we can shorten it with FIPS.We looked at FIPS in Chapter 4, page 52, and we'll look at what to do with the resultant layout on page 66.

Don't forget that if you remove a partition, you lose all the data in it. If the partition contains anything you want to keep, make sure you have a readable backup.

You remove the partition with the d command. After this, your display looks like:

The next step is to allocate a FreeBSD partition. There are two ways to do this: if you want to have more than one partition on the drive (for example, if you share the disk with another operating system), you use the c (create) command. We'll look at that on page 66. In this case, though, you want to use the entire disk for FreeBSD, so you choose the a option. The resultant display is effectively the same as in Figure 5-5 : the only difference is that the Desc field now shows freebsd instead of fat.

That's all you need to do here: leave /disk by pressing the q key.

Don't use the W (Write Changes) command here. It's intended for use only once the system is up and running.

On a PC, the next screen asks what kind of boot selector (in other words, MBR) you want. You don't get this on an Alpha.

If you plan to have only one operating system on this disk, select Standard .If you are sharing with another operating system, you should choose BootMgr instead. We'll look at this in more detail in the section on booting the system on page 529. Exit by pressing the tab key until the OK tab is highlighted, then press Enter.

If you are installing on a disk shared with another operating system, things are a little different. The section continues the example started in Chapter 4 . When you enter the partition editor, you will see something like:

This display shows the two Microsoft partitions, adOsl and ad0s2,which is what you see after using FIPS; if you have just installed Microsoft on one partition, the partition ad0s2 will not be present. If it is, you first need to remove it. Be very careful to remove the correct partition. It's always the second of the two partitions, in this case ad0s2.

Remove the partition by moving the highlight to the second partition and pressing d. After this, the display looks like:

The next step is to allocate a FreeBSD partition with the c command. The menu asks for the size of the partition, and suggests a value of 35899920 sectors, the size of the unused area at the end. You can edit this value if you wish, but in this case it's what you want, so just press ENTER. You get another window asking you for the partition type, and suggesting type 165, the FreeBSD partition table. When you accept that, you get:

The new partition now has a partition type 8 and subtype 165 (0xa5), which identifies it as a FreeBSD partition.

After this, select a boot method as described on page 66 and exit the menu with the q command. There are two operating systems on the disk, so select the BootMgr option.

The next step is to tell the installation program what to put in your FreeBSD partition. First, we'll look at the simple case of installing FreeBSD by itself. On page 75 we'll look at what differences there are when installing alongside another operating system on the same disk.

When you select Label, you get the screen shown in Figure 5-8 .

In this example, you have 20GB of space to divide up. How should you do it? You don't have to worry about this issue, since sysinstall can do it for you, but we'll see below why this might not be the best choice. In this section we'll consider how UNIX file systems have changed over the years, and we'll look at the issues in file system layout nowadays.

When UNIX was young, disks were tiny. At the time of the third edition of UNIX, in 1972, the root file system was on a Digital RF-11, a fixed head disk with 512 kB. The system was growing, and it was no longer possible to keep the entire system on this disk, so a second file system became essential. It was mounted on a Digital RK03 with 2 MB of storage. To quote from a paper published in the Communications of the ACM in July 1974:

In our installation, for example, the root directory resides on the fixed-head disk, and the large disk drive,which contains user's files, is mounted by the system initialization program...

As time went on, UNIX got bigger, but so did the disks. By the early 80s, disks were large enough to put / and /usr on the same disk, and it would have been possible to merge / and /usr, but they didn't, mainly because of reliability concerns. Since that time, an additional file system, /var, has come into common use for frequently changed data, and just recently sysinstall has been changed to create a /tmp file system by default. This is what sysinstall does if you ask it to partition automatically:

It's relatively simple to estimate the size of the root file system, and sysinstall's value of 128 MB is reasonable. But what about /var and /tmp? Is 256 MB too much or too little? In fact, both file systems put together would be lost in the 18.7 GB of /usr file system. Why are things still this way? Let's look at the advantages and disadvantages:

• If you write to a file system and the system crashes before all the data can be written to disk, the data integrity of that file system can be severely compromised. For performance reasons, the system doesn't write everything to disk immediately, so there's quite a reasonable chance of this happening.
• If you have a crash and lose the root file system, recovery can be difficult.
• If a file system fills up, it can cause lots of trouble. Most messages about file systems on the FreeBSD-questions mailing list are complaining about file systems filling up. If you have a large number of small file systems, the chances are higher that one will fill up while space remains on another.
• On the other hand, some file systems are more important than others. If the /var file system fills up (due to overly active logging, for example), you may not worry too much. If your root file system fills up, you could have serious problems.
• In single-user mode, only the root file system is mounted. With the classical layout, this means that the only programs you can run are those in /bin and /sbin.To run other programs, you must first mount the file system on which they are located.
• It's nice to keep your personal files separate from the system files. That way you can upgrade a system much more easily.
• It's very difficult to estimate in advance the size needs of some file systems. For example, on some systems /var can be very small, maybe only 2 or 3 MB. It's hardly worth making a separate file system for that much data. On the other hand, other systems, such as ftp or web servers, may have a /var system of 50 or 100 GB. How do you choose the correct size for your system?
• When doing backups, it's a good idea to be able to get a file system on a single tape.

In the early days of UNIX, system crashes were relatively common, and the damage they did to the file systems was relatively serious. Times have changed, and nowadays file system damage is relatively seldom, particularly on file systems that have little activity. On the other hand, disk drive shave grown beyond most peoples' wildest expectations. The first edition of this book, only six years ago, showed how to install on a 200 MB drive. The smallest disk drives in current production are 20 GB in size, more than will fit on many tapes.

As a result of these considerations, I have changed my recommendations. In earlier editions of this book, I recommended putting a small root file system and a /usr file system on the first (or only) disk on the system. /var was to be a symbolic link to /usr/var.

This is still a valid layout, but it has a couple of problems:

• In the example we're looking at, /usr is about 19 GB in size. Not many people have backup devices that can write this much data on a single medium.
• Many people had difficulty with the symbolic link to /usr/var.

As a result, I now recommend:

• Make a single root file system of between 4 and 6 GB.
• Do not have a separate /usr file system.
• Do not have a separate /var file system unless you have a good idea how big it should be. A good example might be a web server, where (contrary to FreeBSD's recommendations) it's a good idea to put the web pages on the /var file system.
• Use the rest of the space on disk for a /home file system, as long as it's possible to back it up on a single tape. Otherwise make multiple file systems. /home is the normal directory for user files.

This layout allows for easy backup of the file systems, and it also allows for easy upgrading to a new system version: you just need to replace the root file system. It's not a perfect fit for all applications, though. Ultimately you need to make your own decisions.

Apart from files, you should also have at least one swap partition on your disk. It's very difficult to predict how much swap space you need. The automatic option gave you 522 MB, slightly more than twice the size of physical memory. Maybe you can get by with 64 MB. Maybe you'll need 2 GB. How do you decide?

It's almost impossible to know in advance what your system will require. Here are some considerations:

• Swap space is needed for all pages of virtual memory that contain data that is not locked in memory and that can't be recreated automatically. This is the majority of virtual memory in the system.
• Some people use rules of thumb like "2.5 times the size of physical memory, or 64 MB, whichever is bigger." These rules work only by making assumptions about your workload. If you're using more than 2.5 times as much swap space as physical memory, performance will suffer.
• Known memory hogs are X11 and integrated graphical programs such as Netscape and StarOffice. If you use these, you will probably need more swap space. Older UNIX-based hogs such as Emacs and the GNU C compiler (gcc) are not in the same league.
• You can add additional swap partitions on other disks. This has the additional advantage of balancing the disk load if your machine swaps a lot.
• About the only ways to change the size of a swap partition are to add another partition or to reinstall the system, so if you're not sure, a little bit more won't do any harm, but too little can really be a problem.
• If your system panics, and memory dumping is enabled, it will write the contents of memory to the swap partition. This will obviously not work if your swap partition is smaller than main memory. Under these circumstances, the system refuses to dump, so you will not be able to find the cause of the problems.

  The dump routines can only dump to a single partition, so you need one that is big enough. If you have 512 MB of memory and two swap partitions of 384 MB each, you still will not be able to dump.

• Even with light memory loads, the virtual memory system slowly pages out data in preparation for a possible sudden demand for memory. This means that it can be more responsive to such requests. As a result, you should have at least as much swap as memory.

A couple of examples might make this clearer:

1. Some years ago I used to run X, StarOffice, Netscape and a whole lot of other memory-hungry applications on an old 486 with 16 MB. Sure, it was really slow, especially when changing from one application to another, but it worked. There was not much memory, so it used a lot of swap.

   To view the current swap usage, use pstat. Here's a typical view of this machine's swap space:

   $ pstat -s
   Device      1024-blocks    Used   Avail  Capacity  Type
   /dev/da0s1   122880       65148   57668   53%      Interleaved
   

2. At the time of writing I run much more stuff on an AMD Athlon with 512 MB of memory. It has lots of swap space, but what I see is:

   $  pstat –s
   Device      1024-blocks  Used    Avail  Capacity     Type
   /dev/ad0s1b  1048576    14644   1033932    1%     Interleaved
   

It's not so important that the Athlon is using less swap: it's using less than 3% of its memory in swap, whereas the 486 used 4 times its memory. In a previous edition of this book, I had the example of a Pentium with 96 MB of memory, which used 43 MB of swap. Look at it from a different point of view, and it makes more sense: swap makes up for the lack of real memory, so the 486 was using a total of 80 MB of memory, the Pentium was using 140 MB, and the Athlon is using 526 MB. In other words, there is a tendency to be able to say "the more main memory you have, the less swap you need."

If, however, you look at it from the point of view of acceptable performance, you will hear things like "you need at least one-third of your virtual memory in real memory." That makes sense from a performance point of view, assuming all processes are relatively active. And, of course, it's another way of saying "take twice as much swap as real memory."

In summary: be generous in allocating swap space. If you have the choice, use more. If you really can't make up your mind, take 512 MB of swap space or 1 MB more than the maximum memory size you are likely to install.

For the file systems, the column Mount now shows the mount points, and the Newfs column contains the letters UFS1 for UNIX File System, Version 1, and the letter Y, indicating that you need to create a new file system before you can use it. At this point, you have two choices: decide for yourself what you want, or let the disk label editor do it for you. Let's look at both ways:

With these considerations in mind, we'll divide up the disk in the following manner:

• 4GB for the root file system, which includes /usr and /var
• 512 MB swap space
• The rest of the disk for the /home file system

To create a file system, you press c. You get a prompt window asking for the size of the file system, and offering the entire space. Enter the size of the root file system

When you press ENTER, you see another prompt asking for the kind of partition. Select A File System:

When you press ENTER,you see another prompt asking for the mount point for the file system. Enter / for the root file system, after which the display looks like:

It's not immediately obvious at this point that soft updates are not enabled for this file system. Press s to enable them, after which the entry in the Newfs column changes from UFS1 to UFSl+S. See page 191 for reasons why you want to use soft updates.

Next, repeat the operation for the swap partition and the /home file system, entering the appropriate values each time. Don't change the value offered for the length of /home: just use all the remaining space. At the end, you have:

You don't need to enable soft updates for /home; that happens automatically. That's all you need to do. Exit the menu by pressing q.

At this point in the installation, you have told sysinstall the overall layout of the disk or disks you intend to use for FreeBSD, and whether or how you intend to share them with other operating systems. The next step is to specify how you want to use the FreeBSD partitions. First, though, we'll consider some alternative scenarios.

If you have already started an installation and aborted it for some reason after creating the file systems, things will look a little different when you get to the label editor. I twill find the partitions, but it won't know the name of the mount points, so the text under Mount will be <none>. Under Newfs, you will find an asterisk (*) instead of the text UFS1 Y. The label editor has found the partitions, but it doesn't know where to mount the file systems. Before you can use them, you must tell the label editor the types and mount points of the UFS partitions. To do this:

• Position the cursor on each partition in turn.
• Press m (Mount). A window pops up asking for the mount point. Enter the name, in this example, first /, then press Enter. The label editor enters the name of the mount point under Mount, and under Newfs it enters UFS1 N—it knows that this is a UFS file system, so it just checks its consistency and doesn't overwrite it. Repeat this procedure for /home, and you're done. If you are sharing your disk with another system, you can also use this method to specify mount points for your Microsoft file systems. Select the Microsoft partition and specify the name of a mount point.
• Unless you are very sure that the file system is valid, and you really want to keep the data in the partitions, press t to specify that the file system should be created. The text UFS1 N changes to UFS1 Y. If you leave the N there, the commit phase will check the integrity of the file system with fsck rather than creating a new one.

If you have another operating system on the disk, you'll notice a couple of differences. In particular, the label editor menu of Figure 5-8 (on page 68) will not be empty: instead, you'll see something like this:

Be careful at this point. The file system shown in the list is the active Microsoft partition, not a FreeBSD file system. The important piece of information here is the fact that we have 17529 MB of free space on the disk. We'll create the file systems in that free space in the same way we saw on page 72.

The next step is to decide what to install. Figure 5-14 shows you the menu you get when you enter Distributions. A complete installation of FreeBSD uses about 1 GB of space, so there's little reason to choose anything else. Position the cursor on the line All, as shown, and press the space bar.

Next, sysinstall asks you if you want to install the Ports Collection. We'll look at the Ports Collection in Chapter 9 . You don't have to install it now, and it takes much more time than you would expect from the amount of space that it takes: the Ports Collection consists of over 150,000 very small files, and copying them to disk can take as long as the rest of the installation put together. On the other hand, it's a lot easier to do now, so if you have the time, you should install them.

Whatever you answer to this question, you are returned to the distribution menu of Figure 5-14. Select Exit, and you're done selecting your distributions.

Now sysinstall knows the layout of the disk or disks you intend to use for FreeBSD, and what to put on them. Next, you specify where to get the data from.

The next thing you need to specify is where you will get the data from. Where you go now depends on your installation medium. Figure 5-15 shows the Media menu. If you're installing from anything except an ftp server or NFS, you just need to select your medium and then commit the installation, which we look at on page 77. If you're installing from media other than CD-ROM, see page 85.

At this point, sysinstall knows everything it needs to install the software. It's just waiting for you to tell it to go ahead.

So far, every thing you have done has had no effect on the disk drives. If you change your mind, you can just abort the installation, and the data on your disks will be unchanged. That changes completely in the next step, which you call committing the installation. Now is the big moment. You've set up your partitions, decided what you want to install and from where. Now you do it.

If you are installing with the Custom installation, you need to select Commit explicitly. The Standard installation asks you if you want to proceed:

Last Chance!   Are you SURE you want continue the installation?

If you're running this on an existing system, we STRONGLY
encourage you to make proper backups before proceeding.
We take no responsibility for lost disk contents!

When you answer yes, sysinstall does what we've been preparing for:

• It creates the partitions and disk partitions.
• It creates the file system structures in the file system partitions, or it checks them, depending on what you chose in the label editor.
• It mounts the file systems and swap space.
• It installs the software on the system.

After the file systems are mounted, and before installing the software, sysinstall starts processes on two other virtual terminals¹⁾. On /dev/ttyvl you get log output showing you what's going on behind the scenes. You can switch to it with ALT-F2. Right at the beginning you'll see a whole lot of error messages as sysinstall tries to initialize every device it can think of. Don't worry about them, they're normal. To get back to the install screen, press ALT-F1.

In addition, after sysinstall mounts the root file system, it starts an interactive shell on /dev/ttyv3. You can use it if something goes wrong, or simply to watch what's going on while you're installing. You switch to it with ALT-F4.

After installing all the files, sysinstall asks:

Visit the general configuration menu for a chance to set
any last options?

You really have the choice here. You can answer Yes and continue, or you can reboot: the system is now run able. In all probability, though, you will have additional installation work to do, so it's worth continuing. We'll look at that in the following chapter.

Installing FreeBSD on an Alpha (officially Compaq AXP) has a few minor differences due to the hardware itself. In principle, you perform the same steps to install FreeBSD on the Alpha architecture that you perform for the Intel architecture. See page 42 for some differences.

The easiest type of installation is from CD-ROM. If you have a supported CD-ROM drive and a FreeBSD installation CD for Alpha, you can start the installation by building a set of FreeBSD boot floppies from the files fbppies/kern.fp andfbppies/mfsroot.ftp as described for the Intel architecture on page 85. Use the CD-ROM marked "Alpha installation." From the SRM console prompt, insert the kern.flp floppy and type the following command to start the installation:

>>>boot dvaO

Insert the mfsroot.flp floppy when prompted and you will end up at the first screen of the install program. You can then continue as for the Intel architecture on page 59.

To install over the Net, fetch the floppy images from the ftp site, boot as above, then proceed as for the Intel architecture.

Once the install procedure has finished, you will be able to start FreeBSD/Alpha by typing something like this to the SRM prompt:

>>>boot dkcO

This instructs the firmware to boot the specified disk. To find the SRM names of disks in your machine, use the show device command:

>>>show device
dka0.0.0.4.0       DKA0   TOSHIBA CD-ROM XM-57  3476
dkc0.0.0.1009.0    DKC0               RZ1BB-BS  0658
dkc100.1.0.1009.0  DKC100     SEAGATE ST34501W  0015
dva0.0.0.0.1       DVA0
ewa0.0.0.3.0       EWA0      00-00-F8-75-6D-01
pkc0.7.0.1009.0    PKC0          SCSI Bus ID 7  5.27
pqa0.0.0.4.0       PQA0               PCI EIDE

This example comes from a Digital Personal Workstation 433au and shows three disks attached to the machine. The first is a CD-ROM called dka0 and the other two are disks and are called dkc0 and dkc100 respectively.

You can specify which kernel file to load and what boot options to use with the -file and -flags options to boot:

>>>boot -file kernel.old -flags s

To makeFreeBSD/Alpha boot automatically,use these commands:

>>>set boot_osflags a
>>>set bootdef_dev dkcO
>>>set auto_action BOOT

Paradoxically, upgrading an old version of FreeBSD is more complicated than installing from scratch. The reason is that you almost certainly want to keep your old configuration. There's enough material in this topic to fill a chapter, so that's what I've done: see Chapter 31, for more details on how to upgrade a system.

What, you want to remove FreeBSD? Why would you want to do that?

Seriously, if you decide you want to completely remove FreeBSD from the system, this is no longer a FreeBSD issue, it's an issue of whatever system you use to replace it. For example, on page 63 we saw how to remove a Microsoft partition and replace it with FreeBSD; no Microsoft software was needed to remove it. In the same way, you don't need any help from FreeBSD if you want to replace it with a different operating system.

In this section, we'll look at the most common installation problems. Many of these are things that once used to happen and haven't been seen for some time: sysinstall has improved considerably, and modern hardware is much more reliable and easy to configure. You can find additional information on this topic in the section Known Hardware Problems in the file INSTALL.TXT on the first CD-ROM.

sysinstall is intended to be easy to use, but it is not very tolerant of errors. You may well find that you enter something by mistake and can’t get back to where you want to be. In case of doubt, if you haven't yet committed to the install, you can always just reboot.

If you select to install from CD-ROM, you may get the message:

No CD-ROM device found

This might even happen if you have booted from CD-ROM! The most common reasons for this problem are:

• You booted from floppy and forgot to put the CD-ROM in the drive before you booted. Sorry, this is a current limitation of the boot process. Restart the installation (press Ctrl-Alt-DEL or the reset button, or power cycle the computer).
• You are using an ATAPI CD-ROM drive that doesn't quite fit the specification. In this case you need help from the FreeBSD developers. Send a message to FreeBSD-questions@FreeBSD.org and describe your CD-ROM as accurately as you can.

One of the most terrifying things after installing FreeBSD is if you find that the machine just won't boot. This is particularly bad if you have important data on the disk (either another operating system, or data from a previous installation of FreeBSD).

At this point, seasoned hackers tend to shrug their shoulders and point out that you still have the backup you made before you did do the installation. If you tell them you didn't do a backup, they tend to shrug again and move on to something else.

Still, all is probably not lost. The most frequent causes of boot failure are an incorrect boot installation or geometry problems. In addition, it's possible that the system might hang and never complete the boot process. All of these problems are much less common than they used to be, and a lot of the information about how to address them is a few years old, as they haven't been seen since.

It's possible to forget to install the bootstrap, or even to wipe it the existing bootstrap. That sounds like a big problem, but in fact it's easy enough to recover from. Refer to the description of the boot process on page 529, and boot from floppy disk or CD-ROM. Interrupt the boot process with the space bar. You might see:

BTX loader 1.00   BTX version is 1.01
BIOS drive A: is diskO
BIOS drive C: is diskl
BIOS drive D: is disk1
BIOS 639kB/130048kB available memory

FreeBSD/i386 bootstrap loader, Revision 0.8
(grog@freebie.example.com, Thu Jun 13 13:06:03 CST 2002)
Loading /boot/defaults/loader.conf

Hit [Enter] to boot immediately, or any other key for command prompt.
Booting [kernel] in 6 seconds...    press space bar here
ok unload                           unload the current kernel
ok set currdev=disk1s1a             and set the location of the newone
ok load /boot/kernel/kernel         load the kernel
ok boot                             then start it

This boots from the drive /dev/ad0s1a, assuming that you are using IDE drives. The correspondence between the name /dev/ad0s1a and disklsla goes via the information at the top of the example: BTX only knows the BIOS names, so you'd normally be looking for the first partition on drive C. After booting, install the correct bootstrap with bsdlabel -B or boot0cfg, and you should be able to boot from hard disk again.

Things might continue a bit further: you elect to install booteasy, and when you boot, you get the Boot Manager prompt, but it just prints F? at the boot menu and won't accept any input. In this case, you may have set the hard disk geometry incorrectly in the partition editor when you installed FreeBSD. Go back into the partition editor and specify the correct geometry for your hard disk. You may need to reinstall FreeBSD from the beginning if this happens.

It used to be relatively common that sysinstall couldn't calculate the correct geometry for a disk, and that as a result you could install a system, but it wouldn't boot. Since those days, sysinstall has become a lot smarter, but it's still barely possible that you'll run into this problem.

If you can’t figure out the correct geometry for your machine, and even if you don't want to run Microsoft on your machine, try installing a small Microsoft partition at the beginning of the disk and install FreeBSD after that. The install program sees the Microsoft partition and tries to infer the correct geometry from it, which usually works. After the partition editor has accepted the geometry, you can remove the Microsoft partition again. If you are sharing your machine with Microsoft, make sure that the Microsoft partition is before the FreeBSD partition.

Alternatively, if you don't want to share your disk with any other operating system, select the option to use the entire disk (a in the partition editor). You're less likely to have problems with this option.

A number of problems may lead to the system hanging during the boot process. All the known problems have been eliminated, but there's always the chance that something new will crop up. In general, the problems are related to hardware probes, and the most important indication is the point at which the boot failed. It's worth repeating the boot with the verbose fag: again, refer to the description of the boot process on page 529. Interrupt the boot process with the space bar and enter:

Hit [Enter] to boot immediately,  or any other key for command prompt.
Booting [kernel] in 6 seconds...     press space bar here
ok set boot_verbose                  set a verbose boot
ok boot                              then continue

This fag gives you additional information that might help diagnose the problem. See Chapter 29 for more details of what the output means.

If you're using ISA cards, you may need to reconfigure the card to match the kernel, or change the file /boot/device.hints to match the card settings. See the example on page 609. Older versions of FreeBSD used to have a program called UserConfig to perform this function, but it is no longer supported.

If you get the system installed to the point where you can start it, but it doesn't run quite the way you want, don't reinstall. In most cases, reinstallation won't help. Instead, try to find the cause of the problem—with the aid of the FreeBSD-questions mailing list if necessary—and fix the problem.

You might find that the installation completes successfully, and you get your system up and running, but almost before you know it, the root file system fills up. This is relatively unlikely if you follow my recommendation to have one file system for /, /usr and /var, but if you follow the default recommendations, it's a possibility. It could be, of course, that you just haven't made it big enough—FreeBSD root file systems have got bigger over the years. In the first edition of this book I recommended 32 MB "to be on the safe side." Nowadays the default is 128 MB.

On the other hand, maybe you already have an128 MB root file system, and it still fills up. In this case, check where you have put your /tmp and /var file systems. There's a good chance that they're on the root file system, and that's why it's filling up.

Sometimes the system gets into so much trouble that it can't continue. It should notice this situation and stop more or less gracefully. You might see a message like:

panic: free vnode isn't

Syncing disks 14 13 9 5 5 5 5 5 5 5 giving up

dumping to dev 20001 offset 0
dump 16 32 48 64 80 96 112 128 succeeded
Automatic reboot in 15 seconds - press a key on the console to abort
Reboooting...

Just because the system has panicked doesn't mean that you should panic too. It's a sorry fact of life that software contains bugs. Many commercial systems just crash when they hit a bug, and you never know why, or they print a message like General protection fault, which doesn't tell you very much either. When a UNIX system panics, it usually gives you more detailed information-in this example, the reason is free v node isn't. You may not be any the wiser for a message like this (it tells you that the file system handling has got confused about the current state of storage on a disk), but other people might. In particular, if you do get a panic and you ask for help on FreeBSD-questions, please don't just say "My system panicked, what do I do?" The first answer—if you get one— will be "What was the panic string??" The second will be "Where's the dump?"

After panicking, the system tries to write file system buffers back to disk so that they don't get lost. This is not always possible, as we see on the second line of this example. It started off with 14 buffers to write, but it only managed to write 9 of them, possibly because it was confused about the state of the disk. This can mean that you will have difficulties after rebooting, but it might also mean that the system was wrong in its assumptions about the number of buffers needed to be written.

In addition to telling you the cause of the panic, FreeBSD will optionally copy the current contents of memory to the swap file for post-mortem analysis. This is called dumping the system, and is shown on the next two lines. To enable dumping, you need to specify where the dump should be written. In /etc/defaults/rc.conf, you will find:

dumpdev="NO"         # Device name to crashdump to (if enabled)

To enable dumping, put something like this in /boot/loader.conf:

dumpdev="/dev/ad0s1b"

This enables the dumps to be taken even if a panic occurs before the system reads the /etc/rc.conf file. Make sure that the name of the dumpdev corresponds to a swap partition with at least as much space as your total memory. You can use pstat to check this:

# pstat –s
Device      1024-blocks    Used   Avail  Capacity  Type
/dev/ad0s1b       51200   50108    1028     98%    interleaved
/dev/da0s1b       66036   51356   14616     78%    interleaved
/dev/da2s1b      204800   51220  153516     25%    interleaved
Total            321844  152684  169160     47%

As long as this machine doesn't have more than about 192 MB of memory, it will be possible to take a dump on /dev/da2s1b.

In addition, ensure that you have a directory called /var/crash. After rebooting, the system first checks the integrity of the file systems, then it checks for the presence of a dump. If it finds one, it copies the dump and the current kernel to /var/crash.

It's always worth enabling dumping, assuming your swap space is at least as large as your memory. You can analyze the dumps with gdb—see page 623 for more details.

To get the best results from a dump analysis, you need a debug kernel.This kernel is identical to a normal kernel, but it includes a lot of information that can be used for dump analysis. See page 614 for details of how to build a debug kernel. You never know when you might run into a problem, so I highly recommend that you use a debug kernel at all times. It doesn't have any effect on the performance of the system.

A really massive crash may damage your system to such an extent that you need to reinstall the whole system. For example, if you overwrite your hard disk from start to finish, you don't have any other choice. In many cases, though, the damage is repairable. Sometimes, though, you can't start the system to fix the problems. In this case, you have two possibilities:

• Boot from the second CD-ROM (Live Filesystem). It will be mounted as the root file system.
• Boot from the Fixit floppy. The Fixit floppy is in the distribution in the same directory as the boot diskette, ftjppies. Just copy ftoppies/fixit.fp to a disk in the same way as described for boot diskettes on page 85. To use the fixit floppy, first boot with the boot diskette and select "Fixit floppy" from the main menu. The Fixit floppy will be mounted under the root MFS as /mnt2.

In either case, the hard disks aren't mounted; you might want to do repair work on them before any other access.

Use this option only if you have a good understanding of the system installation process. Depending on the damage, you may or may not be successful. If you have a recent backup of your system, it might be faster to perform a complete installation than to try to fix what's left, and after a reinstallation you can be more confident that the system is correctly installed.

The description at the beginning of this chapter applied to the most common installation method, from CD-ROM. In the following sections we'll look at the relatively minor differences needed to install from other media. The choices you have are, in order of decreasing attractiveness:

• Over the network. You have the choice of ftp or NFS connection. If you're connected to the Internet and you're not in a hurry, you can load directly from one of the distribution sites described in the FreeBSD handbook.
• From a locally mounted disk partition, either FreeBSD (if you have already installed it) or Microsoft.
• From floppy disk. This is only for masochists or people who really have almost no hardware: depending on the extent of the installation, you will need up to 250 disks, and at least one of them is bound to have an I/O error. And don't forget that a CD-ROM drive costs a lot less than 250 floppies.

If your machine is no longer the youngest, you may be able to read the CD-ROM drive, but not boot from it. In this case, you'll need to boot from floppy. If you are using 1.44 MB floppies, you will need two or three of them, the Kernel Disk and the MFS Root Disk and possibly the DriversDisk to boot the installation programs. If you are using 2.88 MB floppies or a LS-120 disk, you can copy the single Boot Disk, which is 2.88 MB long, instead of the kernel and MFS root disks. The images of these floppies are on the CD-ROM distribution in the files floppies/kern.fp, floppies/mfsroot.fp, floppies/driv-ers.flp and foppies/boot.fp respectively. If you have your CD-ROM mounted on a Microsoft system, they may be called FLOPPIESKERN.FLP, FLOPPIESMFS-ROOT.FLP, FLOPPIES\DRIVERS.FLP and FLOPPIES\BOOT.FLP respectively. The bootstrap does: not recover bad blocks, so the floppy must be 100% readable.

The way you get the boot disk image onto a real floppy depends on the operating system you use. If you are using any flavour of UNIX, just perform something like:

# dd if=/cdrom/floppies/k:erri.flp of=/dev/fd0 bs=36b
change the floppy
# dd if=/cdrom/floppies/mfsroot.flp of=/dev/fd0 bs=36b
change the floppy
# dd if=/cdrom/floppies/drivers.flp of=/dev/fd0 bs=36b

This assumes that your software is on CD-ROM, and that it is mounted on the directory /cdrom. It also assumes that your floppy drive is called /devfd 0. This is the FreeBSD name as of Release 5.0, and it's also the name that Linux uses. Older FreeBSD and other BSD systems refer to it as /dev/fd0c.

The dd implementation of some versions of UNIX, particularly older System V variants, may complain about the option bs=36b. If this happens, just leave it out. It might take up to 10 minutes to write the floppy, but it will work, and it will make you appreciate FreeBSD all the more.

If you have to create the boot floppy from Microsoft, use the program FDIMAGE.EXE, which is in the tools directory of the first CD-ROM.

In almost all cases where you don't boot from CD-ROM, you'll boot from floppy, no matter what medium you are installing from. If you are installing from CD-ROM, put the CD-ROM in the drive before booting. The installation may fail if you boot before inserting the CD-ROM.

Boot the system in the normal manner from the first floppy (the one containing the kern.flp image). After loading the kernel, the system will print the message:

Please insert MFS root floppy and press enter

After you replace the floppy and press enter, the boot procedure carries on as before.

If you're using the 2.88 MB image on a 2.88 MB floppy or an LS-120 drive, you have every thing you need on the one disk, so you don't get the prompt to change the disk. Depending on your hardware, you may later get a prompt to install additional drivers from the driver floppy.

The fun way to install FreeBSD is via the Internet, but it's not always the best choice. There's a lot of data to transfer, and unless you have a really high-speed, non-overloaded connection to the server, it could take forever. On the other hand, of course, if you have the software on another machine on the same LAN, and the system on which you want to install FreeBSD doesn't have a CD-ROM drive, these conditions are fulfilled, and this could be for you. Before you decide, though, read about the alternative of NFS installation below: if you don't have an ftp server with the files already installed, it's a ot easier to set up an NFS installation.

There are two ftp installation modes you can use:

• Regular ftp mode does not work through most firewalls but will often work best with older ftp servers that do not support passive mode. Use this mode if your connection hangs with passive mode.
• If you need to pass through firewalls that do not allow incoming connections, try passive ftp.

Whichever mode of installation and whichever remote machine you choose, you need to have access to the remote machine. The easiest and most common way to ensure access is to use anonymous ftp. If you're installing from another FreeBSD machine, read how to install anonymous ftp on page 450. This information is also generally correct for other UNIX systems.

Put the FreeBSD distribution in the public ftp directory of the ftp server. On BSD systems, this will be the home directory of user ftp, which in FreeBSD defaults to /var/spool/ftp The name of the directory is the name of the release, which in this example we'll assume to be 5.0-RELEASE. You can put this directory in a subdirectory of /var/spool/ftp, for example /var/spool/ftp/FreeBSD/5.0-RELEASE, but the only optional part in this example is the parent directory FreeBSD.

This directory has a slightly different structure from the CD-ROM distribution. To set it up, assuming you have your distribution CD-ROM mounted on /cdrom, and that you are installing in the directory /var/spool/ftp/FreeBSD/5.0-RELEASE, perform the following steps:

# cd /var/spool/ftp/FreeBSD/5.0-RELEASE
# mkdir floppies
# cd floppies
# cp /cdrom/floppies/* .    don't omit the . at the end
# cd /cdrom                 the distribution directory on CD-ROM
# tar cf - . | (cd /var/spool/ftp/FreeBSD/5.0-EELEASE; tar xvf -)

This copies all the directories of /cdrom into /var/spool/ftp/FreeBSD/5.0-RELEASE. For a minimal installation, you need only the directory base. To just install base rather than all of the distribution, change the last line of the example above to:

# mkdir base
# cp /cdrom/base/* base

On page 77 we saw the media select menu. Figure 5-16 shows the menu you get when you select FTP or FTP Passive.To see the remainder of the sites, use the PageDown key. Let's assume you want to install from presto, a system on the local network. presto isn't on this list, of course, so you select URL. Another menu appears, asking for an ftp pathname in the URL form ftp://hostname/pathname. hostname is the name of the system, in this case presto.example.org, and pathname is the path relative to the anonymous ftp directory, which on FreeBSD systems is usually /var/spool/ftp.The install program knows its version number, and it attaches it to the name you supply.

In this case, we're installing Release 5.0 of FreeBSD, and it's in the directory /var/spool/ftp/pub/FreeBSD/5.0-RELEASE. sysinstall knows the 5.0-RELEASE, so you enter only ftp://presto.example.org/pub/FreeBSD. The next menu asks you to configure your network. This is the same menu that you would normally fill out at the end of the installation—see page 98 for details.

This information is used to set up the machine after installation, so it pays to fill out this information correctly. After entering this information, continue with Commit (on page 77).

If you're installing from a CD-ROM drive on another system in the local network, you might find an installation via ftp too complicated for your liking. Installation is a lot easier if the other system supports NFS. Before you start, make sure you have the CD-ROM mounted on the remote machine, and that the remote machine is exporting the file system (in System V terminology, exporting is called sharing). When prompted for the name of the directory, specify the name of the directory on which the CD-ROM is mounted. For example, if the CD-ROM is mounted on directory /cdrom on the system presto.example.org, enter presto.example.org:/cdrom. That's all there is to it!

Next, you give this information to sysinstall, as shown in Figure 5-17 . After entering this information, sysinstall asks you to configure an interface. This is the same procedure that you would otherwise do after installation—see page 98. After performing this configuration, you continue with Commit (on page 77).

On the Intel architecture you can also install from a primary Microsoft partition on the first disk. To prepare for installation from a Microsoft partition, copy the files from the distribution into a directory called C:\FREEBSD. For example, to do a minimal installation of FreeBSD from Microsoft using files copied from a CD-ROM, copy the directories floppies and base to the Microsoft directories C:\FREEBSD\FLOPPIES and C:\FREEBSD\BIN respectively. You need the directory FLOPPIES because that's where sysinstall looks for the boot.flp, the first image in every installation.

The only required directory is base. You can include as many other directories as you want, but be sure to maintain the directory structure. In other words, if you also wanted to install XF86336 and manpages, you would copy them to C:\FREEBSD\XF86336 and C:\FREEBSD\MANPAGES.

Installation from floppy disk is definitely the worst choice you have. You will need nearly 50 floppies for the minimum installation, and about 250 for the complete installation. The chance of one of them being bad is high. Most problems on a floppy install can be traced to bad media, or differences in alignment between the media and the drive in which they are used, so:

Before starting, format all floppies in the drive you intend to use, even if they are preformatted.

The first two floppies you'll need are the Kernel floppy and the MFS Root floppy, which were described earlier.

In addition, you need at minimum as many floppies as it takes to hold all files in the base directory, which contains the binary distribution. Read the file LAYOUT.TXT paying special attention to the "Distribution format" section, which describes which files you need.

If you're creating the floppies on a FreeBSD machine, you can put ufs file systems on the floppies instead:

# fdformat -f 1440 fd0.1440
# bsdlabel -w fd0.1440 floppy3
# newfs -t 2 -u 18 -l 1 -i 65536 /dev/fd0

Next, copy the files to the floppies. The distribution files are split into chunks that will fit exactly on a conventional 1.44MB floppy. Copy one file to each floppy. Make very sure to put the file base.inf on the first floppy; it is needed to find out how many floppies to read.

The installation itself is straightforward enough: follow the instructions starting on page 63, select Floppy in the installation medium menu on page 76, then follow the prompts.

In the last chapter we looked at the installation of the basic system, up to the point where it could be rebooted. It's barely possible that this could be enough. Almost certainly, though, you'll need to perform a number of further configuration steps before the system is useful. In this chapter we roughly follow the final configuration menu, but there are a few exceptions. The most important things to do are:

• Install additional software.
• Create accounts for normal users.
• Set up networking support.
• Configure the system to start all the services you need.
• Configure the X Window System and desktop.

In this chapter, we’ll concentrate on getting the system up and running as quickly as possible. Later on in the book we'll go into more detail about these topics.

At the end of the previous chapter, we had a menu asking whether we wanted to visit the "last options" menu. If you answer YES, you get the configuration menu shown in Figure 6-1 . If you have rebooted the machine, log in as root and start sysinstall. Then select Configure, which gets you into the same menu.

As the markers under the word Networking indicate, this menu is larger than the window in which it is displayed. We'll look at some of the additional entries below. Only some of these entries are of interest in a normal install; we'll ignore the rest.

There may be some reasons to deviate from the sequence in this chapter. For example, if your CD-ROM is mounted on a different system, you may need to set up networking before installing additional software.

The first item of interest is Packages. These are some of the ports in the Ports Collection, which we'll look at in more detail in Chapter 9 .

The Ports Collection contains a large quantity of software that you may want to install. In fact, there's so much that just making up your mind what to install can be a complicated process: there are over 8,000 ports in the collection. Which ones are worth using? I recommend the following list:

• acroread is the Acrobat reader, a utility for reading and printing PDF files. We look at it briefly on page 276.
• bash is the shell recommended in this book. We'll look at it in more detail on page 113. Other popular shells are tcsh and csh, both in the base system.
• cdrecord is a utility to burn SCSI CD-Rs. We'll discuss it in chapter Chapter 13, Writing CD-Rs. You don't need it if you have an IDE CD-R drive.
• Emacs is the GNU Emacs editor recommended in this book. We'll look at it on page 139. Other popular editors are vi (in the base system) and vim (in the Ports Collection).
• fetchmail is a program for fetching mail from POP mailboxes. We look at it on page 504.
• fvwm2 is a window manager that you may prefer to a full-blown desktop. We look at it on page 118.
• galeon is a web browser. We’ll look at it briefly on page 418.
• ghostscript is a PostScript interpreter. It can be used to display PostScript on an X display, or to print it out on a non-PostScript printer. We'll look at it on page 273.
• gpg is an encryption program.
• gv is a utility that works with ghostscript to display PostScript on an X display. It allows magnification and paging, both of which ghostscript does not do easily. We'll look at it on page 273.
• ispell is a spell check program.
• kde is the desktop environment recommended in this book. We'll look at it in more detail in Chapter 7, The tools of the trade.
• mkisofs is a program to create CD-R images. We look at it in chapter Chapter 13 , Writing CD-Rs
• mutt is the mail user agent (MUA, or mail reader) recommended in Chapter 26 , Electronic mail: clients.
• Postfix is the mail transfer agent (MTA) recommended in chapter Chapter 27, Electronic mail: servers.
• xtset is a utility to set the title of an xterm window. It is used by the .bashrc file installed with the instant-workstation package.
• xv is a program to display images, in particular jpeg and gif.

Why do l recommend these particular ports? Simple: because I like them, and I use most of them myself. That doesn't mean they're the only choice, though. Others prefer the Gnome window manager to kde, or the pine or elm MUAs to mutt, or the vim editor to Emacs. This is the stuff of holy wars. See http://catb.org/~esr/jargon/html/Ufholy-wars.htmlfor more details.

The ports mentioned in the previous section are included in the misc/instant-workstation port, which installs typical software and configurations for a workstation and allows you to be productive right away. At a later point you may find that you prefer other software, in which case you can install it.

It's possible that the CD set you get will not include instant-workstation. That's not such a problem. Due to space restrictions, some CD distributions include instant-workstation-lite instead. If that's not there either, just install the individual ports from this list. You can also do this if you don't like the list of ports.

After installation, you may want to change the default shell for existing users to bash. If you have installed instant-workstation, you should copy the file /usr/lo-cal/share/dot.bashrc to root's home directory and call it .bashrc and .bash_profile. First, start

presto# cp /usr/local/share/dot.bashrc .bashrc
presto# ln .bashrc .bash_profile
presto# bash
=== root@presto (/dev/ttyp2) ~ 1 -> chsh

The last command starts an editor with the following content:

#Changing user database information for root.
Login: root
Password:
Uid [#]: 0
Gid [# or name]: 0
Change [month day year]:
Expire [month day year]:
Class:
Home directory: /root
Shell: /bin/csh
Full Name: Charlie &
Office Location:
Office Phone:
Home Phone:
Other information:

Change the Shell line to:

Shell: /usr/local/bin/bash

Note that the bash shell is in the directory /usr/local/bin; this is because it is not part of the base system. The standard shells are in the directory /bin.

A freshly installed FreeBSD system has a number of users, nearly all for system components. The only login user is root, and you shouldn't log in as root. Instead you should add at least one account for yourself. If you're transferring a master.passwd file from another system, you don't need to do anything now. Otherwise select this item and then the menu item User, and fill out the resulting menu like this:

You should not need to enter the fields UID and Home directory: sysinstall does this for you. It's important to ensure that you are in group wheel so that you can use the su command to become root, and you need to be in group operator to use the shutdown command.

Don't bother to add more users at this stage; you can do it later. We’ll look at user management in Chapter 8 , on page 112.

Next, select Root Password. We’ll talk about passwords more on page 144. Select this item to set the password in the normal manner.

Next, select the entry time zone. The first entry asks you if the machine CMOS clock (i.e. the hardware clock) is set to UTC (sometimes incorrectly called GMT, which is a British time zone). If you plan to run only FreeBSD or other UNIX-like operating systems on this machine, you should set the clock to UTC. If you intend to run other software that doesn't understand time zones, such as many Microsoft systems, you have to set the time to local time, which can cause problems with daylight savings time.

The next menu asks you to select a "region," which roughly corresponds with a continent. Assuming you are living in Austin, TX in the United States of America, you would select America -- North and South and then (after scrolling down) United States of America. The next menu then looks like this: Select Central Time and select Yes when the system asks you whether the abbreviation CST sounds reasonable.

This particular step is relatively cumbersome. You may find it easier to look in the directory /usr/share/zoneinfo after installation. There you find:

# cd /usr/share/zoneinfo/
# ls
Africa       Australia   Etc       MET       WET
America      CET         Europe    MST       posixrules
Antarctica   CST6CDT     Factory   MST7MDT   zone tab
Arctic       EET         GMT       PST8EDT
Asia         EST         HST       Pacific 
Atlantic     EST5EDT     Indian    SystemV

If you want to set the time zone to, say, Singapore, you could enter:

# cd Asia/
# ls
Aden       Chungking  Jerusalem     Novosibirsk  Tehran
Almaty     Colombo    Kabul         Omsk         Thimbu
Amman      Dacca      Kamchatka     Phnom_Penh   Tokyo
Anadyr     Damascus   Karachi       Pyongyang    Ujung_Pandang
Aqtau      Dili       Kashgar       Qatar        Ulaanbaatar
Aqtobe     Dubai      Katmandu      Rangoon      Ulan -Bator
Ashkhabad  Dushanbe   Krasnoyarsk   Riyadh       Urumqi
Baghdad    Gaza       Kuala_Lumpur  Saigon       Vientiane
Bahrain    Harbin     Kuching       Samarkand    Vladivostok
Baku       Hong_Kong  Kuwait        Seoul        Yakutsk
Bangkok    Hovd       Macao         Shanghai     Yekaterinburg
Beirut     Irkutsk    Magadan       Singapore    Yerevan
Bishkek    Istanbul   Manila        Taipei
Brunei     Jakarta    Muscat        Tashkent
Calcutta   Jayapura   Nicosia       Tbilisi
# cp Singapore /etc/localtime

Note that the files in /usr/share/zoneinfo/Asia (and the other directories) represent specific towns, and these may not correspond with the town in which you are located. Choose one in the same country and time zone.

You can do this at any time on a running system.

The next step is to configure your networking equipment. Figure 6-4 shows the Network Services Menu. There are a number of ways to get to this menu:

• If you're running the recommended Custom installation, you'll get it automatically after the end of the installation.
• If you're running the Standard and Express installations, you don't get it at all: after setting up your network interfaces, sysinstall presents you with individual items from the Network Services Menu instead.
• If you're setting up after rebooting, or if you missed it during installation, select Configure from the main menu and then Networking.

The first step should always be to set up the network interfaces, so this is where you find yourself if you are performing a Standard or Express installation.

Figure 6-5 shows the network setup menu. On a standard 80x25 display it requires scrolling to see the entire menu. If you installed via FTP or NFS, you will already have set up your network interfaces, and sysinstall won't ask the questions again. The only real network board on this list is xl0, the Ethernet board. The others are standard hardware that can also be used as network interfaces. Don't try to set up PPP here; there's more to PPP configuration than sysinstall can handle. We'll look at PPP configuration in Chapter 20 .

In our case, we choose the Ethernet board. The next menu asks us to set the internet parameters. Figure 6-6 shows the network configuration menu after filling in the values. Specify the fully qualified local host name; when you tab to the Domain: field, the domain is filled in automatically. The names and addresses correspond to the example network that we look at in Chapter 16, on page 294. We have chosen to call this machine presto, and the domain is example.org. In other words, the full name of the machine is presto.example.org. It's IP address is 223.147.37.2. In his configuration, all access to the outside world goes via gw.example.org, which has the IP address 223.147.37.5. The name server is located on the same host, presto.example.org. The name server isn't running when this information is needed, so we specify all addresses in numeric form.

What happens if you don't have a domain name? If you're connecting to the global Internet, you should go out and get one—see page 318. But in the meantime, don't fake it. Just leave the fields empty. If you're not connecting to the Internet, of course, it doesn't make much difference what name you choose.

As is usual for a class C network, the net mask is 255.255.255.0. You don't need to fill in this information—if you leave this field without filling it in, sysinstall inserts it for you. Normally, as in this case, you wouldn't need any additional options to ifconfig.

It's up to you to decide what other network options you would like to use. None of the following are essential, and none need to be done right now, but you may possibly find some of the following interesting:

• inetd allows connections to your system from outside. We'll look at it in more detail on page 448. Although it's very useful, it's also a security risk if it's configured incorrectly. If you don't want to accept any connections from outside, you can disable inetd and significantly reduce possible security exposures.
• NFS client. If you want to mount NFS file systems located on other machines, select this box. An X appears in the box, but nothing further happens. See Chapters 24 and 25 for further details of NFS.
• NFS server. If you want to allow other systems to mount file systems located on this machine, select this box. You get a prompt asking you to create the file /etc/exports, which describes the conditions under which other systems can mount the file systems on this machine. You must enter the editor, but there is no need to change anything at this point. We'll look at /etc/exports in more detail on page 463.
• ntpdate and ntpd are programs that automatically set the system time from time servers located on the Internet. See page 156 for more details. If you wish, you can select the server at this point.
• rwhod broadcasts information about the status of the systems on the network. You can use the ruptime program to find the uptime of all systems running rwhod, and rwho to find who is running on these systems. On a normal-sized display, you need to scroll the menu down to find this option.
• You don't need to select sshd: it's already selected for you. See page 453 for further details of ssh and sshd.

You don't need to specify any of the remaining configuration options during configuration. See the online handbook for further details.

The next step of interest is the Startup submenu, which allows you to choose settings that take effect whenever you start the machine. See Chapter 29 for details of the startup files.

• Select APM if you're running a laptop. It enables you to power the system down in suspend to RAM or suspend to disk mode, preserving the currently running system, and to resume execution at a later date.
• If you have USB peripherals, select usbd to enable the usbd daemon, which recognizes when USB devices are added or removed.
• named starts a name daemon. Use this if you're connecting to the Internet at all, even if you don't have a DNS configuration: the default configuration is a caching name server, which makes name resolution faster. Just select the box; you don't need to do anything else. We'll look at named in Chapter 21 .
• Select lpd, the line printer daemon, if you have a printer connected to the machine. We'll look at lpd in Chapter 15 .
• Select Linux if you intend to run Linux binaries. This is almost certainly the case, and by default the box is already ticked for you.
• Select SVR4 and SCO if you intend to run UNIX System V.4 (SVR4) or SCO OpenDesktop or OpenServer (SCO) binaries respectively.

FreeBSD detects PS/2 mice at boot time only, so the mouse must be plugged in when you boot. If not, you will not be able to use it. To configure, select Mouse from the configuration menu. The menu in Figure 6-8 appears.

With a modern PS/2 mouse, you don't need to do any configuration at all. You just enable the mouse daemon or moused. Select the menu item Enable: you have the chance to move the mouse and note that the cursor follows. The keys don't work in this menu: select Yes and exit the menu. That's all you need to do.

If you're running a serial mouse, choose the item Select mouse port and set it to correspond with the port you have; if you have an unusual protocol, you may also need to set it with the Type menu. For even more exotic connections, read the man page for moused and set the appropriate parameters.

You should have installed X along with the rest of the system—see page 75. If you haven't, install the package x11/XFree86. In this section, we'll look at what you need to do to get X up and running.

X configuration has changed a lot in the course of time, and it's still changing. The current method of configuring X uses a program called x/86c/g, which is still under development, and it shows a few strangeness’s. Quite possibly the version you get will not behave identically with the following description. The differences should be relatively clear, however.

The configuration is stored in a file called XF86Config, thhough the directory has changed several times in the last few years. It used to be in /etc/X11/XF86Config or

/etc/XF86Config, but the current preferred place is /usr/X11R6/lib/X11/XF86Config.The server looks for the configuration file in multiple places, so if you're upgrading from an earlier version, make sure you remove any old configuration files. We'll look at the contents of the file in detail in Chapter 28 . In this section, we'll just look at how to generate a usable configuration.

From the configuration menu, select XFree86 and then xf86cfg. There is a brief delay while xf86cfg creates an initial configuration file, then you see the main menu of Figure 6-9. This application runs without knowing what the hardware is, so the rendering is pretty basic. The window on the left shows the layout of the hardware, and the window on the right is available in case your mouse isn't working. Select the individual components with the mouse or the numeric keypad. For example, to configure the mouse, select the image at top left:

In all likelihood that won't be necessary. The configuration file that xf86cfg has already created may be sufficient, so you could just exit and save the file. You'll probably want to change some things, though. In the following, we'll go through the more likely changes you may want to make.

You can select a number of options for the keyboard, including alternative key layouts. You probably won't need to change anything here.

Probably the most important thing you need to change are the definitions for the monitor and the display card. Some modern monitors and most AGP display cards supply the information, but older devices do not. In this example we'll configure a Hitachi CM813U monitor, which does not identify itself to x/86cfg. Select the monitor image at the top right of the window, then Configure Monitor(s). You see:

xf86cfg doesn't know anything about the monitor, so it assumes that it can only display standard VGA resolutions at 640x480. The important parameters to change are the horizontal and vertical frequencies. You can select one of the listed possibilities, but unless you don't know your's monitor specifications, you should set exactly the frequencies it can do. In this case, the monitor supports horizontal frequencies from 31 kHz to 115 kHz and vertical frequencies from 50 Hz to 160 Hz, so that's what we enter. At the same time, we change the identifier to indicate the name of the monitor:

Select OK to return to the previous menu.

xf86cfg recognizes most modern display cards, including probably all AGP cards, so you probably don't need to do anything additional to configure the display card. If you find that the resultant configuration file doesn't know about your card, you'll have to select the card symbol at the top of the screen. Even if the card has been recognized, you get this display:

The only indication you have that xf86cfg has recognized the card (here a Matrox G200) is that it has selected mga for the driver name. If you need to change it, scroll down the list until you find the card:

The display resolution is defined by Mode Lines, which we'll look at in detail on page 513. The names relate to the resolution they offer. By default, xf86cfg only gives you 640x480, so you'll certainly want to add more. First, select the field at the top left of the screen:

From this menu, select Configure ModeLine. You see:

If you pass the cursor over the image of the screen, you'll see this warning:

Take it seriously. We’ll look at this issue again in Chapter 28 on page 510. For an initial setup, you shouldn't use this interface. Instead, select Add standard VESA mode at the top. We get another menu:

Select the resolutions you want with the highest frequency that your hardware can handle. In this case, you might select 1024x768 @ 85 Hz, because it's still well within the range of the monitor. Answer yes to the question of whether you want to add it. You can select as many resolutions as you want, but the ModeLine window does not show them.

You can also use the ModeLine window to tune the display, but it's easier with another program, xvidtune.We'll look at those details in Chapter 28 .

Finally, select Quit at the bottom right of the display. You get this window:

When you answer Yes, you get a similar question asking whether you want to save the keyboard definition. Once you've done that, you're finished.

Next, select Desktop from the Configuration menu. You get this menu:

Which one do you install? You have the choice. If you know what you want, use it. There are many more window managers than shown here, so if you don't see what you're looking for, check the category x11-wm in the Ports Collection. The select menu gives you the most popular ones: Gnome, Afterstep, Enlightenment, KDE, Window maker and fwm2. In this book, we'll consider the KDE desktop and the fvwm2 window manager. KDE is comfortable, but it requires a lot of resources. Gnome is similar in size to KDE. By contrast, fvwm2 is much faster, but it requires a fair amount of configuration. We'll look at KDE and fvwm2 in Chapter 7 .

At this point, we're nearly done. A few things remain to be done:

• Decide how you want to start X. You can do it explicitly with the startx command, or you can log in directly to X with the xdm display manager. If you choose start x, you don't need to do any additional configuration.
• For each user who runs X, create an X configuration file.

To enable xdm, edit the file /etc/t/ys. By default it contains the following lines:

ttyv8  "/usr/X11R6/bin/xdm  -nodaemon"  xterm  off secure

Using an editor, change the text off to on:

ttyv8  "/usr/X11R6/bin/xdm  -nodaemon"  xterm  on secure

If you do this from a running system, send a HUP signal to init to cause it to re-read the configuration file and start xdm:

# kill -1 1

This causes an xdm screen to appear on /dev/ttyv8. You can switch to it with Alt-F9.

If you're starting X manually with startx, create a file .xinitrc in your home directory. This file contains commands that are executed when X starts. Select the line that corresponds to your window manager or desktop from the following list, and put it in .xinitrc:

 
Startkde    for kde
exec gnome-session   for Gnome
fvwm2        for fvwm2

If you're using xdm, you put the same content in the file .xsession in your home directory.

When you get this for, you should have a functional system. If you're still installing from CD-ROM, you reboot by exiting sysinstall. If you have already rebooted, you exit sysinstall and reboot with:

# shutdown -r now

Don't just press the reset button or turn the power off. That can cause data loss. We'll look at this issue in more detail on page 541.

So now you have installed FreeBSD, and it successfully boots from the hard disk. If you're new to FreeBSD, your first encounter with it can be rather puzzling. You probably didn't expect to see the same things you know from other platforms, but you might not have expected what you see either:

   FreeBSD (freebie.example.org) (ttyvO)
login:

If you have installed xdm, you'll at least get a graphical display, but it still asks you to log in and provide a password. Where do you go from here?

There isn't space in this book to explain everything there is about working with FreeBSD, but in the following few chapters I'd like to make the transition easier for people who have prior experience with Microsoft platforms or with other favours of UNIX. You can find a lot more information about these topics in UNIX for the Impatient, by Paul W. Abrahams and Bruce R. Larson, UNIX Power Tools, by Jerry Peek, Tim O'Reilly, and Mike Loukides, and UNIX System Administration Handbook, by Evi Nemeth, Garth Snyder, Scott Seebass, and Trent R. Hein. The third edition of this book also covers FreeBSD Release 3.2. See Appendix A, Bibliography, for more information.

If you've come from Microsoft, you will notice a large number of differences between UNIX and Microsoft, but in fact the two systems have more in common than meets the eye. Indeed, back in the mid-80s, one of the stated goals of MS-DOS 2.0 was to make it more UNIX-like. You be the judge of how successful that attempt was, but if you know The MS-DOS command-line interface, you'll notice some similarities in the following sections.

In this chapter, we'll look at FreeBSD from the perspective of somebody with computer experience, but with no UNIX background. If you do have a UNIX background, you may still find it interesting.

If you're coming from a Microsoft platform, you'll be used to doing just about everything with a graphical interface. In this book I recommend that you use X and possibly a desktop, but the way you use it is still very different. FreeBSD, like other UNIX-like systems, places much greater emphasis on the use of text. This may seem primitive, but in fact the opposite is true. It's easier to point and click than to type, but you can express yourself much more accurately and often more quickly with a text interface.

As a result, the two most important tools you will use with FreeBSD are the shell and the editor. Use the shell to issue direct commands to the system, and the editor to prepare texts. We'll look at these issues in more detail in this chapter. In Chapter 8, Taking control, we'll look at other aspects of the system. First, though, we need to get access to the system.

Probably the biggest difference between most PC operating systems and FreeBSD also takes the longest to get used to: FreeBSD is a multi-user, multi-tasking system. This means that many people can use the system at once, and each can do several things at the same time. You may think "Why would I want to do that?" Once you've got used to this idea, though, you'll never want to do without it again. If you use the X Window System, you'll find that all windows can be active at the same time—you don't have to select them. You can monitor some activity in the background in another window while writing a letter, testing a program, or playing a game.

Before you can access a FreeBSD system, you must be registered as a user. The registration defines a number of parameters:

• A user name, also often called user ID. This is a name that you use to identify yourself to the systcode.
• A password, a security device to ensure that other people don't abuse your user ID. To log in, you need to specify both your user ID and the correct password. When you type in the password, nothing appears on the screen, so that people looking over your shoulder can't read it.

  It might seem strange to go to such security measures on a system that you alone use. The incidence of Internet-related security problems in the last few years has shown that it's not strange at all, it's just common sense. Microsoft systems are still subject to a never-ending series of security exploits. FreeBSD systems are not.

• A shell, a program that reads in your commands and executes them. MS-DOS uses the program COMMAND.COM to perform this function. UNIX has a large choice of shells: the traditional UNIX shells are the Bourne shell sh and the C shell csh, but FreeBSD also supplies bash, tcsh, zsh and others. I personally use the bash shell, and the examples in this book are based on it.
• A home directory.The system can have multiple users, so each one needs a separate directory in which to store his private files. Typically, users have a directory /home/username, where username is the name they use to login. When you login to the system, the shell sets the current directory to your home directory. In it, you can do what you want, and normally it is protected from access by other users. Many shells, including the bash shell used in these examples, use the special notation ~(tilde) to represent the name of the home directory.
• A group number. UNIX collects users into groups who have specific common access permissions. When you add a user, you need to make him a member of a specific group, which is entered in the password information. Your group number indirectly helps determine what you are allowed to do in the system. As we'll see on page 181, your user and group determine what access you have to the system. You can belong to more than one group.

  Group numbers generally have names associated with them. The group names and numbers are stored in the file /etc/group. In addition, this file may contain user IDs of users who belong to another group, but who are allowed to belong to this group as well.

  If you find the concept of groups confusing, don't worry about them. You can get by quite happily without using them at all. You'll just see references to them when we come to discuss file permissions. For further information, look at the man page for Group (5).

By the time you get here, you should have defined a user name, as recommended on page 94. If you haven't, you'll have to login as root and create one as described there.

Once you have a user name, you can log in to the system. Already you have a choice: FreeBSD offers both virtual terminals and the X WindowSystem. The former displays plain text on the monitor, whereas the latter uses the system's graphics capabilities. Once running, you can switch from one to the other, but you have the choice of which interface you use first. If you don't do anything, you get a virtual terminal. If you run xdm, you get X.

It's still relatively uncommon to use xdm, and in many instances you may not want X at all, for example if you're running the system as a server. As a result, we'll look at the "conventional" login first.

If you're logging in on a virtual terminal, you'll see something like this:

login:    grog
Password:              password doesn't show on the screen
Last login: Fri Apr 11 16:30:04 from canberra
Copyright (c)  1980, 1983, 1986,  1988, 1990,  1991, 1993, 1994
    The Regents of the University of California. All rights reserved.

FreeBSD 5.0-RELEASE (FREEBIE) #0: Tue Dec 31 19:08:24 CST 2002

Welcome to FreeBSD!

You have mail.
erase ^H, kill ^U, intr ^C, status ^T
Niklaus Wirth has lamented that, whereas Europeans pronounce his name
correctly (Ni-klows Virt), Americans invariably mangle it into
(Nick-les Worth).  Which is to say that Europeans call him by name, but
Americans call him by value.
 === grog@freebie (/dev/ttyv0) ~ 1 ->

There's a lot of stuff here. It's worth looking at it in more detail:

• The program that asks you to login on a terminal window is called getty. It reads in your user ID and starts a program called login and passes the user ID to it.
• login asks for the password and checks your user ID.
• If the user ID and password are correct, login starts your designated shell.
• While starting up, the shell looks at a number of files. See the man page for your particular shell for details of what they are for. In this case, though, we can see the results: one file contains the time you last logged in, another one contains the Message of the day (/etc/motd), and a third one informs you that you have mail. The shell prints out the message of the day verbatim - in this case; it contains information about the name of the kernel and a welcome message. The shell also prints information on last login time (in this case, from a remote system) and whether you have mail.
• The line "erase ^H, kill ^U, intr ^C, status ^T" looks strange. It's telling you the current editing control characters. We'll look at these on page 131. At this point, the shell changes the current directory to your home directory.There is no output on the screen to indicate this.
• The shell runs the fortune program, which prints out a random quotation from a database of "fortune cookies." In this case, we get a message about Niklaus Wirth, the inventor of the Pascal programming language.
• Finally, the last line is a prompt, the information that tells you that the shell is ready for input.

The prompt illustrates a number of things about the UNIX environment. By default, sh and friends prompt with a $, and csh and friends prompt with a %. You can change it to just about anything you want with the UNIX shells. You don't have to like my particular version, but it's worth understanding what it's trying to say.

The first part, ===, is just to make it easier to find in a large list on an X display. An xterm window on a high resolution X display can contain up to 120 lines, and searching for command prompts can be non-trivial.

Next, grog@freebie is my user ID and the name of system on which I am working, in the RFC 2822 format used for mail IDs. Multiple systems and multiple users can all be present on a single X display. This way, I can figure out which user I am and what system I am running on.

/dev/ttyv0 is the name of the terminal device. This can sometimes be useful.

~ is the name of the home directory. Most shells, but not all of them, support this symbolism.

1 is the prompt number. Each time you enter a command, it is associated with this number, and the prompt number is incremented. One way to re-execute the command is to enter !!1 (two exclamation marks and the number of the command). We'll look at more comfortable ones on page 131.

To start X from a virtual terminal shell, use the startx command:

$ startx

If you use xdm, you bypass the virtual terminals and go straight into X. Enter your user name and password to the login prompt or the xdm login screen, and press Enter. If you use the xdm login, you'll go straight into X.

Either way, assuming that you've installed and configured kde, you'll get a display similar to that in Figure 7-1 . This example includes four windows that are not present on startup. On startup the central part of the screen is empty. We'll look at the windows further below.

KDE is a complicated system, and good documentation is available at http://www.kde.0rg/documentation/. Once you have KDE running, you can access the same information via the help icon on the panel at the bottom (the life ring icon). The following description gives a brief introduction.

The KDE display contains a number of distinct areas. At the top is an optional menu, at the bottom an almost optional panel, and the middle of the screen is reserved for windows.

The Desktop Menu is at the very top of the screen. It provides functionality that is not specific to a particular application. Select the individual categories with the mouse. For example, the New menu looks like this:

As the menu indicates, you can use these menus to create new files.

At the bottom of the screen is the panel, which consists of a number of fields. The left-hand section is used for starting applications.

The stylized letter K at the extreme left is the Application Starter. When you select it, a long vertical menu appears at the left of the screen and allows you to start programs ("applications") or access just about any other function.

Next comes an icon called "showdesktop." This is a convenient way to iconify all the windows currently on the desktop.

The remaining icons on this part of the panel represent various applications.

• The konsole terminal emulator.
• The command center, which you use to configure KDE.
• The help system.
• Access to the home directory with the browser konqueror.
• Access to the Web, also with the browser konqueror.
• The Kmail MUA.
• The KWord word processor, which can understand Microsoft Word documents.
• The Kspread spreadsheet.
• The Kpresenter presentation package.
• The Kate editor.

The next section of the panel contains some control buttons and information about the current desktop layout:

The section at the left shows the current contents of four screens, numbered 1 to 4. Screen 1 is the currently displayed screen; you can select one of the others by moving the cursor in the corresponding direction, or by selecting the field with the mouse.

To the right of that are icons for the currently active windows. The size expands and contracts depending on the number of different kinds of window active. If you select one of these icons with the left mouse button, it will iconify or deiconify ("minimize" or "maximize") the window. If you have multiple xterms active, you will only have one icon. In this case, if you select the icon, you will get another pop-up selection menu to allow you to choose the specific window.

The right part of the panel contains a further three fields:

• The first one shows a stylized padlock (for locking the session when you leave the machine; unlock by entering your password) and a stylized off switch, for logging out of the session.
• The next section shows a stylized power connector, which displays the current power status of the machine, and a clipboard.
• The right side shows a digital clock.

Probably the most useful part of this section of the panel is not very obvious: the right-pointing arrow allows you to remove the panel if you find it's in the way. The entire panel is replaced by a single left-pointing arrow at the extreme right of the display.

By default, kde only uses the left and the right mouse buttons. In general, the left button is used to select a particular button, and the right button is used for an auxiliary menu.

You'll notice that each window has a frame around it with a number of features. In X terminology, they're called decorations. Specifically:

• There's a title bar with the name of the program. If you select the bar itself, you raise the window above all others. If you hold down the button on the title bar, you can move the window.
• At the left of the title bar there is an X logo. If you select this logo, you get a menu of window operations.
• At the right of the title bar, there are three buttons that you can select. The left one iconifies the window, the middle one maximizes the window, making it take up the entire screen, and the one on the right kills the application. If the window is already maximized, the middle button restores it to its previous size.
• You can select any corner of the window, or any of the other edges, to change the size of the window.

If you come from a conventional PC background, you shouldn't have much difficulty with KDE. It's a relatively complete, integrated environment. But it isn't really UNIX. If you come from a UNIX environment, you may find it too all-encompassing. You may also find that there are significant delays when you start new applications.

UNIX has a very different approach to windows. There is no desktop; just a window manager. It takes up less disk space, less processor time, and less screen real estate. By default, XFree86 comes with the twm window manager, but that's really a little primitive. With modern machines, there's no reason to choose such a basic window manager. You may, however, find that fvwm2 is more your style than KDE.

Like KDE, you install fvwm2 from the Ports Collection. It's not designed to work completely correctly out of the box, though it does work. As with KDE, the first thing you need to do is to create a .xsession or .xinitrc file, depending on whether you're running xdm. It must contain at least the line:

fvwm2

Start X the same way you did for KDE. This time you see, after starting the same applications as before:

This picture shows both similarities with and differences from KDE. The similarities include:

• Each window has a frame and a title. The exact form of the decorations is different, but the purpose is the same. There is no "close application" button: for most UNIX applications, you should get the program to exit rather than killing it.
• There is a task bar at the bottom right, taking up only half the width of the screen. The currently active window (the xterm at the left in this example) is highlighted.
• The default fvwm2 display also has four screens, and the task bar shows the position of the windows on the task bar.

Still, there are a number of differences as well:

• Unless you have a top-end machine, it's much faster in what it does.
• The background (the root window) doesn't have any pattern; it's just a grey cross-hatch.
• You can move from one screen to the other using the cursor, and windows can overlap. In this example, the galeon web browser window goes down to the screen below, and the Emacs window goes overall four screens, as the display on the task bar shows. With KDE, the only way to display the rest of these windows is to move the window.
• Paradoxically, you can do a lot more with the mouse. On the root window, the left mouse button gives you a menu for starting various programs, both locally and remotely, and also various window utilities. The middle button gives you direct access to the window manipulation utilities, and the right button gives a drop-down list to select any of the currently active windows:
  
  
  
  увеличить изображение
  
  Рис. 7.7. 

The menus above show one of the problems: look at those system names on the left submenu (dopey, snoopy and friends). They don't exist on our sample network and the chance of them existing on your network is pretty low as well. They're hard-coded in the sample configuration file, /usr/X11R6/etc/system.fvwm2rc. To use fvwm2 effectively; you'll have to modify the configuration file. The best thing to do is to make a copy of /usr/X11R6/etc/system.fvwm2rc in your own directory, as ~/.fVwm2/.fvwm2rc. Then you can have lots of fun tweaking the file to do exactly what you want it to do. Clearly, KDE is easier to set up.

When you set up your XF86Config file, you may have specified more than one resolution. For example, on page 107 we selected the additional resolution 1024x768 pixels. When you start X, it automatically selects the first resolution, in this case 640x480. You can change to the previous resolution (the one to the left in the list) by pressing the Ctrl-Alt-Keypad - key, and to the following resolution (the one to the right in the list) with Ctrl-Alt-Keypad +. Keypad + and Keypad - refer to the + and - symbols on the numeric keypad at the right of the keyboard; you can't use the + and - symbols on the main keyboard for this purpose. The lists wrap around: in our example, if your current resolution is 640x480, and you press Ctrl-Alt-Keypad -, the display changes to 1024x768. It's a very good idea to keep the default resolution at 640x480 until you have debugged your XF86Config parameters: 640x480 almost always works, so if your display is messed up, you can just switch back to a known good display with a single keystroke.

You can configure most display boards to display a number of different pixel depths (a different number of bits per pixel, which translates to a different number of colours). When you start X, however, it defaults to 8 bits per pixel (256 colours), which is a very poor rendition. To start it with a different number, specify the number of planes. For example, to start with 32 bits per pixel (4,294,967,296 colours), enter:

$ Startx ---bpp 32

With older display boards, which had relatively limited display memory, there was a tradeoff between maximum resolution and maximum pixel depth. Modern display cards no longer have this limitation.

As we saw at the beginning of the chapter, your main tools are the shell and the editor, and that's what we saw on the sample screens. But when you start X, they're not there: you need to start them.

In KDE, you have two ways to start a terminal window:

• You can select the icon showing a monitor with a shell in front of it, third from the left at the bottom of the example above. This starts the konsole terminal emulator.
• You can start an xterm by pressing Alt-F2.You see a window like the one in the centre left of Figure 7-1 , enter the text xterm (as shown) and press Run or the Enter key.

Obviously the first is the intended approach, and it's easier. Nevertheless, I recommend using xterm at least until you're sure you want to stick with kde: there are some subtle differences, and konsole is intended to work with kde only. If you do stick with KDE, you should change the configuration of the konsole button to start xterm instead; that's relatively straightforward.

In fvwm2, you start an xterm from the left mouse menu, as shown above.

The most basic thing you can do with the shell is to start a program. Consider program names to be commands: like you might ask somebody to "wash the dishes" or "mow the lawn," you can tell the shell to "remove those files":

$ rm filel file2 file3

This starts a program called rm (remove), and gives it a list of three file names to remove.

If you're removing a whole lot of files, this could take a while. Consider removing the entire directory hierarchy /usr/obj, which is created when building a new version of the system (see page 595). This directory hierarchy contains about 15,000 files and directories, and it'll take a while to remove it. You can do this with the following command:

# rm -rf /usr/obj &

In this example, we have a couple of options led in by a hyphen (-) and also the character & at the end of the line.

• The r option tells rm to recursively descend into subdirectories. If you didn't specify this, it would remove all files in the directory /usr/obj and then exit, complaining that it can't delete directories.
• The f (force) option tells rm to continue on error; otherwise if anything goes wrong, it will stop.
• The & character at the end of the line tells the shell (not rm) to continue after starting the program. It can run for some time, and there's no need to wait for it.

In the previous example, we saw a couple of options. By convention, they come between the command name and other parameters, and they're identified because they start with a hyphen character (-). There's a lot of variation, though, is depending on the individual program.

• Sometimes, as in the previous example, options consist of a single letter and can often be joined together.
• Some programs, like tar and ps, don't insist on the hyphen lead-in. In Chapter 8 , we'll see the command:

  # ps waux
  

  This command could equally well be written:

  #  ps –waux
  

  You may also come across programs that refuse to accept the hyphen at all.

• Sometimes options can have values. For example, in Chapter 23 we'll see:

  #  tcpdump -i pppO host hub.freebsd.org
  

  Here, ppp0 is an argument to the i option. In some cases, it must be written with a space; in others, it must be written without a space; and in others again, it can be written either way. Pay attention to this detail when reading man pages.

• In other cases, they can be keywords, in which case they need to be written separately. The GNU project is particularly fond of this kind of option. For example, when building the system you may see compiler invocations like these:

  cc -O -pipe -Dinline=rpcgen_inline -Wall –Wno–format-y2K -Wno-uninitialized
  \-D_FBSDID=_RCSID -c /usr/src/usr.bin/rpcgen/rpc_main.c
  

  With the exception of the last parameter, all of these texts are options, as the hyphen suggests.

• Options are specific to particular commands, though often several commands attempt to use the same letters to mean the same sort of thing. Typical ones are v for verbose output, q for quiet output (i.e. less than normal).
• Sometimes you can run into problems when you supply a parameter that looks like an option. For example, how do you remove a file called -rf? There are a number of solutions for this problem. In this example, you could write:

  $ rm ./-rf
  

This is an alternative file naming convention.

When you invoke a program with the shell, it first parses the input line before passing it to the program: it turns the line into a number of parameters (called arguments in the C programming language). Normally the parameters are separated by white space, either a space or a tab character. For example, consider the previous example:

$ rm file1 file2 file3

the program receives four arguments, numbered 0 to 3:

What happens if you want to pass a name with a space? For example, you might want to look for the text "Mail rejected" in a log file. UNIX has a standard program for looking for text, called grep. The syntax is:

grep expression files

Argument 1 is the expression; all additional arguments are the names of files to search. We could write:

$ grep Mail rejected /var/log/maillog

But that would try to look for the text Mail in the files rejected (probably causing an error message that the file did not exist) and /var/log/maillog (where just about every line contains the text Mail). That's not what we want. Instead, we do pretty much what I wrote above:

$ grep "Mail rejected" /var/log/maillog

In other words, if we put quote characters "" around a group of words, the shell will interpret them as a single parameter. The first parameter that is passed to grep is Mail rejected, not "Mail rejected".

This behaviour of the shell is a very good reason not to use file names with spaces in them. It's perfectly legitimate to embed spaces into UNIX files names, but it's a pain to use. If you want to create a file name that contains several words, for example All files updated since last week, consider changing the spaces to underscores: All_files_updated_since_last_week.

It's even more interesting to see what happens when you pass a globbing character to a program, for example:

$ cc -o foo *.c

This invocation compiles all C source files (*.c) and creates a program foo. If you do this with Microsoft, the C compiler gets four parameters, and it has to find the C source files itself. In UNIX, the shell expands the text *.c and replaces it with the names of the source files. If there are thirty source files in the directory, it will pass a total of 33 parameters to the compiler.

The solution to the "Mail rejected" problem isn't ideal, but it works well enough as long as you don't have to handle fields with blanks in them too often. In many cases, though, particularly in configuration files, fields with blanks are relatively common. As a result, a number of system configuration files use a colon (:) as a delimiter. This looks very confusing at first, but it turns out not to be as bad as the alternatives. We'll see some examples in the PATH environment variable on page 130, in the password file on page 144, and in the login class file on page 571.

Both UNIX and Microsoft environments store disk data in files, which in turn are placed in directories .A file may be a directory: that is, it may contain other files. The differences between UNIX and Microsoft start with file names. Traditional Microsoft file names are rigid: a file name consists of eight characters, possibly followed by a period and another three characters (the so-called file name extension). There are significant restrictions on which characters may be used to form a file name, and upper and lower case letters have the same meaning (internally, Microsoft converts the names to UPPER CASE). Directory members are selected with a backslash (\), which conflicts with other meanings in the C programming language—see page 138 for more details.

FreeBSD has a very fexible method of naming files. File names can contain any character except /, and they can be up to 255 characters long. They are case-sensitive: the names FOO, Foo and foo are three different names. This may seem silly at first, but any alternative means that the names must be associated with a specific character set. How do you upshift the German name ? What if the same characters appear in a Russian name? Do they still shift the same? The exception is because the / character represents directories. For example, the name /home/fred/longtext-with-a-long-name represent:

First character is a /, representing the root file system.

home is the name of a directory in the root file system.

fred is the name of a directory in /home.

The name suggests that longtext-with-a-long-name is probably a file, not a directory, though you can't tell from the name.

As a result, you can't use / in a file name. In addition, binary 0s (the ASCII NUL character) can confuse a lot of programs. It's almost impossible to get a binary 0 into a file name anyway: that character is used to represent the end of a string in the C programming language, and it's difficult to input it from the keyboard.

Case sensitivity no longer seems as strange as it once did: web browsers have made UNIX file names more popular with Uniform Resource Indicators or URIs, which are derived from UNIX names.

The Microsoft naming convention (name, period and extension) seems similar to that of UNIX. UNIX also uses extensions to represent specific kinds of files. The difference is that these extensions (and their lengths) are implemented by convention, not by the file system. In Microsoft, the period between the name and the extension is a typographical feature that only exists at the display level: it's not part of the name. In UNIX, the period is part of the name, and names like foo.bar.bazzot are perfectly valid file names. The system doesn't assign any particular meaning to file name extensions; instead, it looks for magic numbers, specific values in specific places in the file.

Every directory contains two directory entries, . and .. (One and two periods). These are relative directory entries: . is an alternative way to refer to the current directory, and .. refers to the parent directory. For example, in /home/fred, . refers to /home/fred, and .. refers to /home. The root directory doesn't have a parent directory, so in this directory only, .. refers to the same directory. We'll see a number of cases where this is useful¹⁾.

Most systems have a method of representing groups of file names and other names, usually by using special characters for representing an abstraction. The most common in UNIX are the characters *,? and the square brackets []. UNIX calls these characters globbing characters. The Microsoft usage comes from UNIX, but the underlying file name representation makes for big differences. Table 7-2 gives some examples.

Most programs either read input data or write output data. To make it easier, the shell usually starts programs with at least three open files:

• Standard input, often abbreviated to stdin, is the file that most programs read to get input data.
• Standard output, or stdout, is the normal place for programs to write output data.
• Standard error output, or stderr, is a separate file for programs to write error messages.

With an interactive shell (one that works on a terminal screen, like we're seeing here), all three files are the same device, in this case the terminal you're working on.

Why two output files? Well, you may be collecting something important, like a backup of all the files on your system. If something goes wrong, you want to know about it, but you don't want to mess up the backup with the message.

But of course, even if you're running an interactive shell, you don't want to back up your system to the screen. You need to change stdout to be a file. Many programs can do this themselves; for example, you might make a backup of your home directory like this:

$ tar -cf /var/tmp/backup-

This creates (option c) a file (option f) called /var/tmp/backup, and includes all the files in your home directory (~). Any error messages still appear on the terminal, as stderr hasn't been changed.

This syntax is specific to tar.The shell provides a more general syntax for redirecting input and output streams. For example, if you want to create a list of the files in your current directory, you might enter:

$ ls -l
drwxr-xr-x  2 root  wheel  512   Dec  20  14:36  CVS
-rw-r--r--    1 root  wheel  7928  Oct  23  12:01  Makefile
-rw-r--r--    5 root  wheel  209   Jul  26  07:11  amd.map
-rw-r--r--    5 root  wheel  1163  Jan  31  2002  apmd.conf
-rw-r--r--    5 root  wheel  271   Jan  31  2002  auth.conf
-rw-r--r--    1 root  wheel  741   Feb  19  2001  crontab
-rw-r--r--    5 root  wheel  108   Jan  31  2002  csh.cshrc
-rw-r--r--    5 root  wheel  482   Jan  31  2002  csh.login
(etc)

You can redirect this output to a file with the command:

$ ls -l > /var/tmp/etclist

This puts the list in the file /var/tmp/etclist. The symbol > tells the shell to redirect stdout to the file whose name follows. Similarly, you could use the < to redirect stdin to that file, for example when using grep to look for specific texts in the file:

$ grep csh < /var/tmp/etclist
  -rw-r--r--     5 root   wheel  108 Jan 31  2002 csh.cshrc
  -rw-r--r--     5 root   wheel  482 Jan 31  2002 csh.login
  -rw-r--r--     5 grog   lemis  110 Jan 31  2002 csh.logout

In fact, though, there's a better way to do that: what we're doing here is feeding the output of a program into the input of another program. That happens so often that there's a special method of doing it, called pipes:

| grep csh
  -rw-r--r--     5 root  wheel  108 Jan 31  2002 csh.cshrc
  -rw-r--r--     5 root  wheel  482 Jan 31  2002 csh.login
  -rw-r--r--     5 grog  lemis  110 Jan 31  2002 csh.logout

The | symbol causes the shell to start two programs. The first has a special file, a pipe, as the output, and the second has the same pipe as input. Nothing gets written to disk, and the result is much faster.

A typical use of pipes is to handle quantities of output data in excess of a screenful. You can pipe to the less²⁾program, which enables you to page backward and forward:

$ ls -l | less

Another use is to sort arbitrary data:

$ ps aux | sort -n +1

This command takes the output of the ps command and sorts it by the numerical (-n) value of its second column (+1). The first column is numbered 0.

The UNIX programming model includes a concept called environment variables. This rather unusual sounding name is simply a handy method of passing relatively long-lived information of a general nature from one program to another. It's easier to demonstrate the use than to describe. Table 7-3 takes a look at some typical environment variables. To set environment variables from Bourne-style shells, enter:

 $ export TERM=xterm

This sets the value of the TERM variable to xterm. The word export tells the shell to pass this information to any program it starts. Once it's exported, it stays exported. If the variable isn't exported, only the shell can use it.

Alternatively, if you want to set the variable only once when running a program, and then forget it, you can set it at the beginning of a command line:

$ TERM=xterm-color mutt

This starts the mutt mail reader (see page 474) with xterm's colour features enabled.

For csh and tcsh, set environment variables with:

% setenv TERM xterm

To start a process with these variables, enter:

% env xterm-color mutt

Note particularly the PATH variable. One of the most popular questions in the FreeBSD-questions mailing list is "I have compiled a program, and I can see it in my directory, but when I try to run it, I get the message "command not found." This is usually because PATH does not include the current directory.

$ ./program

You should set your PATH variable to point to the most common executable directories. Add something like this to your .profile file (for Bourne-style shells):

PATH=/usr/bin:/usr/local/bin:/usr/sbin:/bin:/sbin:/usr/X11R6/bin
export PATH

This variable is of great importance: one of the leading problems that beginners have is to have an incorrect PATH variable.

So you can't start a program, and you're wondering whether your PATH environment variable is set correctly. You can find out with the echo command:

$ echo $PATH
/bin:/usr/bin

The $ at the beginning of $PATH tells the shell to substitute the value of the environment variable for its name. Without this, the shell has no way of knowing that it's an environment variable, so it passes the text PATH to echo, which just prints it out.

If you want to print out all the environment variables, use the printenv command:

$ printenv | sort
BLOCKSIZE=1048576
CLASSPATH=/usr/local/java/lib:/usr/local/java/lib/classes.zip:/hcme/grcg/netscape/
CVSROOT=/home/ncvs
DISPLAY=freebie:0
EDITOR=emacs
HOME=/home/grog
PAGER=less
PATH=.:/usr/bin:/usr/sbin:/bin:/sbin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin
XAUTHORITY=/home/grog/.Xauthority

This example sorts the variables to make it easier to find them. In all probability, you'll find many more variables.

Typing is a pain. If you're anything like me, you're continually making mistakes, and you may spend more time correcting typing errors than doing the typing in the first place. It's particularly frustrating when you enter something like:

$ groff -rex=7.5 -r$$ -rL -rW -rN2 -mpic tmac.M unixerf.nm
troff: fatal error: can't open 'unixerf.mm': No such file or directory

This command should create the PostScript version of this chapter, but unfortunately I messed up the name of the chapter: it should have been unixref.mm, and I typed unixerf.mm.

Yes, I know this looks terrible. In fact, UNIX has ways to ensure
 you almost never need to write commands like this. The command I really use to format this chapter
is "make unixref".

It would be particularly frustrating if I had to type the whole command in again. UNIX offers a number of ways to make life easier. The most obvious one is so obvious that you tend to take it for granted: the Backspace key erases the last character you entered. Well, most of the time. What if you're running on a machine without a Backspace key? You won't have that problem with a PC, of course, but a lot of workstations have a DEL key instead of a Backspace key. UNIX lets you specify what key to use to erase the last character entered. By default, the erase character really is DEL, but the shell startup changes it and prints out a message saying what it has done:

 erase ^H, kill ^U, intr ^C, status ^T

in the example on page 113. ^H (Ctrl-H) is an alternative representation for Backspace.

The three other functions kill, intr, and status perform similar editing functions. Kill erases the whole line, and intr stops a running program.

You'll notice that it is set to Ctrl-C, so its function is very similar to that of the MS-DOS Break key. status is an oddball function: it doesn't change the input, it just displays a statistics message. bash doesn't in fact use it: it has a better use for Ctrl-T.

In fact, these control characters are just a few of alarge number of control characters that you can set. Table 7-4 gives a nover view of the more common control characters. For a complete list, see the man page stty(1).

To set these characters, use the stty program. For example, if you're used to erasing the complete input line with Ctrl-X, and specifying an end-of-file condition with Ctrl-Z, you could enter:

$ stty susp \377 kill "X eof "Z

You need to set SUSP to something else first, because by default it is Ctrl-Z, so the system wouldn't know which function to perform if you press "Z.

In this particular case, ^X really does mean the character ^ followed by the letter X, and not Ctrl-X, the single character created by holding down the Control character and pressing X at the same time.

Nowadays, most shells supply a command history function and additional functionality for editing it. We'll take a brief look at these features here—for more details see the man pages for your shell.

Shell command line editing has been through a number of evolutionary phases. The original Bourne shell supplied no command line editing at all, though the version supplied with FreeBSD gives you many of the editing features of more modern shells. Still, it's unlikely that you'll want to use the Bourne shell as your shell: bash, ksh, and zsh are all compatible with the Bourne shell, but they also supply better command line editing.

The next phase of command line editing was introduced with the C shell, csh.By modern standards, it's also rather pitiful. It's described in the csh man page if you really want to know. About the only part that is still useful is the ability to repeat a previous command with the !! construct. Modern shells supply command line editing that resembles the editors vi or Emacs. In bash, sh, ksh, and zsh you can make the choice by entering:

$ set -o emacs   for Emacs-style editing
$ set -o vi      for vi-style editing

In tcsh, the corresponding commands are:

% bind emacs
% bind vi

Normally you put one of these commands in your startup file.

In Emacs mode, you enter the commands simply by typing them in. In vi mode, you have to press ESC first. Table 7-5 shows an overview of the more typical Emacs-style commands in bash. Many other shells supply similar editing support.

As the name suggests, the Emacs editor understands the same editing characters. It also understands many more commands than are shown here. In addition, many X-based commands, including web browsers, understand some of these characters.

You'll note a number of alternatives to the cursor keys. There are two reasons for them: firstly, the shell and Emacs must work on systems without arrow keys on the keyboard. The second reason is not immediately obvious: if you're a touch-typer, it's easier to type Ctrl-P than take your hands away from the main keyboard and look for the arrow key. The arrows are good for beginners, but if you get used to the control keys, you'll never miss the arrow keys.

As we have seen, UNIX file names can be much longer than traditional Microsoft names, and it becomes a problem to type them correctly. To address this problem, newer shells provide file name completion. In Emacs mode, you typically type in part of the name, then press the Tab key. The shell checks which file names begin with the characters you typed. If there is only one, it puts in the missing characters for you. If there are none, it beeps (rings the "terminal bell"). If there are more than one, it puts in as many letters as are common to all the file names, and then beeps. For example, if I have a directory docco in my home directory, I might enter:

=== grog@freebie (/dev/ttyp4) ~ 14 -> cd docco/
=== grog@freebie (/dev/ttyp4) "/docco 15 -> ls freebsd.faq   freebsd.fbc freeware
=== grog@freebie (/dev/ttyp4) "/docco 16 -> emacs freebeepbsd.fbeepaq

Remember that my input is in constant width bold font, and the shell's output is in constant width font. On the first line, I entered the characters cd doc followed by a Tab character, and the shell completed with the text co/. On the last line, I entered the characters emacs f and a Tab. In this case, the shell determined that there was more than one file name that started like this, so it added the letters ree and rang the bell. I entered the letter b and pressed Tab again, and the shell added the letters sd.f and beeped again. Finally, Iadded the letters aq to complete the file name freebsd.faq.

Command line completion in vi mode is similar: instead of pressing Tab, you press ESC twice.

As we saw above, there are a lot of ways to customize your shell. It would be inconvenient to have to set them every time, so all shells provide a means to set them automatically when you login. Nearly every shell has its own startup file. Table 7-6 gives an overview.

These files are shell scripts—in other words, straight shell commands. listing 7-1 shows a typical .bashrc file to set the environment variables we discussed.

umask 022
export BLOCKSIZE=1024     #for df
export CVSROCT=/src/ncvs
export EDITCR=/opt/bin/emacs
export MANPATH=/usr/share/man:/usr/local/man
export MCZILLA_HOME=/usr/local/netscape
export PAGER=less
export PATH=/usr/bin:/usr/local/bin:/usr/sbin:/bin:/sbin:/usr/X11R6/bin
PS1="=== \u@\h rtty1) \w \# -> "
PS2="\u@\h \w \! ++ "
export SHELL=/usr/local/bin/bash
export TAPE=/dev/nsa0     #note non-rewinding as standard 
if [ "$TERM" = "" ]; then
  export TERM=xterm
fi
if [ "$DISPLAY" = "" ]; then
  export DISPLAY=:0
fi
/usr/games/fortune       # print a fortune cookie

It would be tedious for every user to put settings in their private initialization files, so the shells also read a system-wide default file. For the Bourne shell family, it is /etc/profile, while the C shell family has three files: /etc/csh.login to be executed on login, /etc/csh.cshrc to be executed when a newshell is started after you login, and /etc/csh.logout to be executed when you stop a shell. The start files are executed before the corresponding individual files.

In addition, login classes (page 571) offer another method of setting environment variables at a global level.

The FreeBSD installation gives root a C shell, csh.This is the traditional BSD shell, but it has a number of disadvantages: command line editing is very primitive, and the script language is significantly different from that of the Bourne shell, which is the de facto standard for shell scripts: if you stay with the C shell, you may still need to understand the Bourne shell. The latest version of the Bourne shell sh also includes some command line editing. See page 133 for details of how to enable it.

If you want to stay with a csh-like shell, you can get better command line editing with tcsh, which is also in the base system. You can get both better command line editing and Bourne shell syntax with bash, in the Ports Collection.

If you have root access, you can use vipw to change your shell, but there's a more general way: use chsh (ChangeShell). Simply run the program. It starts your favourite editor (as defined by the EDITOR environment variable). Here's an example before:

#Changing user database information for velte.
Shell: /bin/csh
Full Name: Jack Velte
Location:
Office Phone:
Home Phone:

You can change anything after the colons. For example, you might change this to:

#Changing user database information for velte.
Shell: /usr/local/bin/bash
Full Name: Jack Velte
Location: On the road
Office Phone: +1-408-555-1999
Home Phone:

chsh checks and updates the password files when you save the modifications and exit the editor. The next time you login, you get the new shell. chsh tries to ensure you don't make any mistakes—or example, it won't let you enter the name of a shell that isn't mentioned in the file /etc/shells—but it's a very good idea to check the shell before logging out. You can try this with su, which you normally use to become super user:

bumble# su velte Password:
su-2.00$       note the newprompt

You might hear objections to using bash as a root shell. The argument goes something like this: bash is installed in /usr/local/bin, so it's not available if you boot into single-user mode, where only the root file system is available. Even if you copy it to, say, /bin, you can't run it in single-user mode because it needs libraries in /usr/lib.

In fact, this isn't a problem. If you install the system the way I recommend in Chapter 5, /usr is on the root file system. Even if it isn't, though, you don't have to use bash in single-user mode. When you boot to single-user mode, you get a prompt asking you which shell to start, and suggesting /bin/sh.

If you're coming from a Microsoft background, there are a few got chas that you might trip over.

/ (slash) and \ (backslash) are confusing. As we've seen, UNIX uses / to delimit directories. The backslash \ is called an escape character. It has, several purposes:

• You can put it in front of another special character to say "don't interpret this character in any special way."We've seen that the shell interprets a space character as the end of a parameter. In the previous example we changed Mail rejected to "Mail rejected" to stop the shell from interpreting it. We could also have written: Mail\ rejected.

  A more common use for this quoting is to tell the shell to ignore the end of a line. If acommand line in a shell script gets too long, you might like to split it up into several lines; but the shell sees the end of a line as a go-ahead to perform the command. Stop it from doing so by putting a backslash immediately before the end of the line:

  $ grep \
  "Mail rejected" \
     /var/log/maillog
  

  Don't put any spaces between the \ and the end of the line; otherwise the shell will interpret the first space as a parameter by itself, and then it will interpret the end of line as the end of the command.

• In the C programming language, the backslash is used to represent several control characters. For example, \n means "new line." This usage appears in many other places as well.
• Using \ as an escape character causes problems: how do we put a \ character on a line? The answer: quote it. Write \\ when you mean \. This causes particular problems when interfacing with Microsoft: if you give a Microsoft path name to a shell, it needs the doubled backslashes: C:\\WINDOWS.

We've seen that the shell treats "white space," either spaces or tab characters, as the same. Unfortunately, some other programs do not. make, sendmail and syslogd make a distinction between the two kinds of characters, and they all require tabs (not spaces) in certain places. This is a real nuisance, because hardly any editor makes a distinction between them.

In the olden days, the standard computer terminal was a Teletype, a kind of computer-controlled electric type writer. When the carriage, which contained the print head, got to the end of a line, it required two mechanical operations to move to the beginning of the next line: the carriage return control character told it to move the carriage back to the beginning of the line, and the line feed character told it turn the platen to the next line.

Generations of computer systems emulated this behaviour by putting both characters at the end of each text line. This makes it more difficult to recognize the end of line, it uses up more storage space, and normally it doesn't buy you much. The implementors of UNIX decided instead to use a single character, which it calls the newline character. For some reason, they chose the line feed to represent new line, though the character generated by Enter is a carriage return. As we saw a bove, the C programming language represents it as \n.

This causes problems transferring data between FreeBSD and Microsoft, and also when printings to printers that still expect both characters. We'll look at the file transfer issues on page 260 and the printer issues on page 267.

A part from the shell, your second most important tool is the editor, a program that creates and changes texts. Another divergence of concept between UNIX and Microsoft environments is that UNIX gives you a choice of editors in just about anything you do. Microsoft products frequently try to redefine the whole environment, so if you change mailers, you may also have to change the editor you use to write mail. This has a profound effect on the way you work. In particular, the Microsoft way makes it uninteresting to write a really good editor, because you can't use it all the time.

The standard BSD editor is vi, about which people speak with a mixture of admiration, awe and horror. vi is one of the oldest parts of BSD. It is a very powerful editor, but nobody would say that it is easy to learn. There are two reasons to use vi:

• If you're already an experienced vi hacker, you probably won't want to change.
• If you do a lot of work on different UNIX systems, you can rely on vi being there. It's about the only one on which you can rely.

If, on the other hand, you don't know vi, and you only work on systems whose software you can control, you probably shouldn't use vi. Emacs is much easier to learn, and it is more powerful than vi.

When running under X, Emacs displays its own window (v/' uses an xterm under these circumstances). As are sult, if you start Emacs from an xterm, you should use the & character to start it in the background:

$ emacs &

Figure 7-8 shows the resulting display. As you can see, the first thing that Emacs offers you is a tutorial. You should take it. You'll also notice the menu bars at the top. Although they look primitive compared to graphics toolbars, they offer all the functionality of graphics-oriented menus. In addition, they will tell you the keystrokes that you can use to invoke the same functions. Figure 7-9 gives an example of the Files menu.

There is a lot of documentation for Emacs, much of it on line. The complete Emacs handbook is available via the info mode of Emacs, which is described in the tutorial. If that's not enough, read Learning GNU Emacs, byDebra Cameron, Bill Rosenblatt and Eric Raymond.

To stop X, press the key combination Ctrl-Alt-Backspace, which is deliberately chosen to resemble the key combination Ctrl-Alt-Delete used to reboot the machine. Ctrl-Alt-Backspace stops X and returns you to the virtual terminal in which you started it. If you run from xd/w, it reds plays a login screen.

To stop the system, use the shutdown program. To do so, you need to be a member of group operator.

By default, KDE uses the halt program. Only root can use this program, so you should reconfigure KDE to use shutdown. After this, you can shut down from KDE with the keystroke combination Ctrl-Alt-PageDown.

In Chapter 7 we saw the basics of working with FreeBSD. In this part of the book, we'll look at some more system-specific issues. This chapter discusses the following topics:

• UNIX is a multi-user operating system. We've already skimmed over creating user accounts, but on page 144 we'll look at it in more detail.
• Not all users are created equal. In particular, the system administration login root has power overall other users. We'll look at root on page 146.
• UNIX implements multi-tasking via a mechanism called processes. We’ll look at them on page 148.
• Timekeeping is extremely important in a networking system. If your system has the wrong time, it can cause all sorts of strange effects. On page 155 we'll look at how to ensure that your system is running the correct time.
• A number of events are of interest in keeping a machine running smoothly. The system can help by keeping track of what happens. One mechanism for this is log files files that contain information about what has happened on the machine. We'll look at them on page 157.
• On page 159, we'll look at how FreeBSD handles systems with more than one processor. This is also called Symmetrical Multi-Processor or SMP support.
• Nearly every modern laptop has as special bus for plugin cards. It used to be called PCMCIA an acronym for the rather unlikely name Personal Computer Memory Card International Association. Nowadays it's called PC Card. It was later upgraded to a 32 bit bus called CardSus We'll look at how FreeBSD supports PC Card and CardBus on page 159.
• Starting on page 162, we'll look at FreeBSD's support for emulating other operating systems.
• Other aspects of FreeBSD are so extensive that we'll dedicate separate chapters to them. We'll look at them in Chapters 9 to 15.
• Starting and stopping the system is straightforward, but there are a surprising number of options. Many of them are related to networking, so Chapter 29 is located after the networking section.

We've already looked at users in Chapter 7. In this chapter, well take a deeper look.

In traditional UNIX, information about users was kept in the file /etc/passwd. As the name suggests, it included the passwords, which were stored in encrypted form. Any user could read this file, but the encryption was strong enough that it wasn't practical to decrypt the passwords. Nowadays processors are much faster, and it's too easy to crack a password. As a result, FreeBSD keeps the real information in a file called /etc/mas-ter.passwd, and for performance reasons it also makes it available in database form in /etc/pwd.db and /etc/spwd.db. None of these file are user-readable. /etc/passwd remains for compatibility reasons: some third-party programs access it directly to get information about the environment in which they are running.

So what user name do you choose? User names are usually related to your real name and can be up to eight characters long. Like file names, they're case-sensitive. By convention, they are in all lower case, even when they represent real names. Typical ways to form a user name are:

• First name. In my personal case, this would begreg.
• Last name lehey
• First name and initial of last name gregl
• Initial of first name, and last name glehey
• Initials gpl
• Nickname (for example, grog)

I choose the last possibility, as we will see in the following discussion.

We've already seen how to use sysinstall to create a user. It's not the only way. There are at least two other methods. One is the program adduser:

# adduser
Use option "-verbose" if you want see more warnings & questions or try to repair bugs.
Enter username [a-z0-9]:  yana
Enter full name []:  Yana Lehey
Enter shell bash csh date no sh [bash]:        accept the default
Uid [1000]:                                    accept the default
Enter login class:  default []:                accept the default
Login group yana [yana]:  home
Login group is "home". Invite  yana into other groups:  no
[no]:  wheel                                   to be able to use su
Enter password []:                             no echo
Enter password again []:                       no echo

Name:      yana
Password:  ****
Fullname:  Yana Lehey
Uid:       1000
Gid:       1001 (home)
Class:
Groups:    home wheel
HOME:      /home/yana
Shell:     /bin/bash
OK? (y/n)   [y]:                              accept the default
Added user "yana"
Add another user? (y/n)   [y]: n

An alternative way of adding or removing users is with the vipw program. This is a more typical UNIX-hackish approach: vipw starts your favorite editor and allows you to edit the contents of the file /etc/master.passwd. After you have finished; it checks the contents and rebuilds the password database. Figure 8-1 shows an example.

You might be wondering why would you ever want to do things this way, and you might find it funny that most experienced UNIX administrators prefer it. The reason is that you get more of an overview than with a peephole approach that graphical environments give you, but of course you need to understand the format better. It's less confusing once you know that each line represents a single user, that the lines are divided into fields (which may be empty), and that each field is separated from the next by a colon (:). Table 8-1 describes the fields you see on the line on which the cursor is positioned. You can read more about the format of /etc/master.passwd in the man page passwd(5).

FreeBSD has a number of privileged users for various administration functions. Some are just present to be the owners of particular files, while others, such as daemon and uucp, exist to run particular programs. One user stands above all others, however: root may do just about anything. The kernel gives root special privileges, and you need to become root to perform a number of functions, including adding other users. Make sure root has a password if there is any chance that other people can access your system (this is a must if you have any kind of dialup access). Apart from that, root is a user like any other, but to quote the man page su(1):

By default (unless the prompt is reset by a startup file) the super user prompt is set to # to remind one of its awesome power.

Frequently when you're logged in normally, you want to do something that requires you to be root. You can log out and log in again as root, of course, but there's an easier way:

$ su        become super user
Password:   as usual, it doesn't echo
#           root prompt

To use su , you must be a member of the group wheel. Normally you do this when you add the user, but otherwise just put the name of the user at the end of the line in /etc/group:

wheel:*:0:root,grog    add the text in boldface

Having a single root password is a security risk on a system where multiple people know the password. If one of them leaves the project, you need to change the password. An alternative is the sudo port (/usr/ports/security/sudo). It provides fine-grained access to root privileges, all based on the user's own password. Nobody needs to know the root password. If a user leaves, you just remove his account, and that cancels his access.

If your system has any connection with the outside world, it's a good idea to change your password from time to time. Do this with the passwd program. The input doesn't look very interesting:

$ passwd
Changing local password for yana.
Old password:                        doesn't echo
New password:                        doesn't echo
Retype new password:                 doesn't echo
passwd: rebuilding the database...
passwd: done

You have to enter the old password to make sure that some passer-by doesn't change it for you while you're away from your monitor, and you have to enter the new password twice to make sure that you don't mistype and lock yourself out of your account. If this does happen anyway, you can log in as root and change the password: root doesn't have to enter the old password, and it can change anybody's password. For example:

# passwd yana
Changing local password for yana.
New password:                     doesn't echo
Retype new password:              doesn't echo
passwd: rebuilding the database...
passwd: done

In this case, you specify the name of the user for whom you change the password.

If you are changing the root password, be careful: it's easy enough to lock your self out of the system if you mess things up, which could happen if, for example, you mistyped the password twice in the same way (don't laugh, it happens). If you're running X, open another window and use su to become root If you're running in character mode, select another virtual terminal and log in as root there. Only when you're sure you can still access root should you log out.

If you do manage to lose the root password, all may not be lost. Reboot the machine to single-user mode (see page 540), and enter:

# mount -u /           mount root file system read/write
# mount /usr           mount /usrfile system (if separate)
# passwd root          change the password for root
Enter new password:
Enter password again:
# ^D                   enter ctrl-D to continue with startup

If you have a separate /usr file system (the normal case), you need to mount it as well, since the passwd program is in the directory /usr/bin. Note that you should explicitly state the name root: in single-user mode, the system doesn't have the concept of user IDs.

As we have seen, UNIX is a multi-user, multi-tasking operating system. In particular, you can run a specific program more than once. We use the term process to refer to a particular instance of a running program. Each process is given a process ID more frequently referred to as PID a number between 0 and 99999 that uniquely identifies it. There are many things that you might like to know about the processes that are currently running, such as:

• How many processes are running?
• Who is running the processes?
• Why is the system so slow?
• Which process is blocking my access to the modem?

Your primary tool for investigating process behavior is the ps (process status) command. It has a large number of command options, and it can tell you a whole lot of things that you will only understand when you have investigated how the kernel works, but it can be very useful for a number of things. Here are some typical uses:

After starting a large number of processes in a number of windows under X, you probably can't remember what is still running? Maybe processes that you thought had stopped are still running. To display a brief summary of the processes you have running, use the ps command with no options:

$ ps
PID  TT  STAT    TIME  COMMAND
187  p0  Is+  0:01.02  -bash (bash)
188  Pi  Ss   0:00.62  -bash (bash)
453  Pi  R+   0:00.03  ps

This display shows the following information:

• The PID of the process.
• TT is short for teletype, and shows the last few letters of the name of thecontrolling terminal, the terminal on which the process is running. In this example, the terminals are /dev/ttyp0 and /dev/ttypl.
• STAT shows the current process status. It's involved and requires a certain amount of understanding of how the kernel runs to interpret it—see the man page for ps for more details.
• TIME is the CPU time that the process has used in minutes, seconds and hundredths of a second. Note that many other UNIX systems, particularly System V, only show this field to the nearest second.
• COMMAND is normally the command you entered, but don't rely on this. In the next section, you'll see thatsendmail has changed its COMMAND field to tell you what it is doing. You'll notice that the command on the last line is the ps that performs the listing. Due to some complicated timing issue in the kernel, this process may or may not appear in the listing.

There are many more processes in the system than the list above shows. To show them all, use the a option to ps. To show daemons as well (see the next section for a definition of daemon ), use the x option. To show much more detail, use the u or l options. For example:

$ ps waux
USER    PID  %CPU  %MEM   VSZ   RSS  TT  STAT  STARTED        TIME  COMMAND
root     12  95.7   0.0     0    12  ??  RL     1Jan70  1406:43.85  (idle: cpu0)
root     11  95.1   0.0     0    12  ??  RL     1Jan70  1406:44.64  (idle: cpu1)
root      1   0.0   0.0   708    84  ??  ILs    1Jan70     0:09.10  /sbin/init
root     12   0.0   0.0     0    12  ??  WL     1Jan70    15:04.95  (swi1: net)
root     13   0.0   0.0     0    12  ??  WL     1Jan70    21:30.29  (swi6: tty:sio clock)
root     15   0.0   0.0     0    12  ??  DL     1Jan70     2:17.27  (random)
root     18   0.0   0.0     0    12  ??  WL     1Jan70     0:00.00  (swi3: cambio)
root     20   0.0   0.0     0    12  ??  WL     1Jan70     0:00.00  (irq11: ahc0 uhci0++)
root     21   0.0   0.0     0    12  ??  WL     1Jan70    39:00.32  (irq5: rl0)
root     22   0.0   0.0     0    12  ??  WL     1Jan70     7:12.92  (irq14: ata0)
root     23   0.0   0.0     0    12  ??  WL     1Jan70     0:47.99  (irq15: ata1)
root     24   0.0   0.0     0    12  ??  DL     1Jan70     0:00.08  (usb0)
root     25   0.0   0.0     0    12  ??  DL     1Jan70     0:00.00  (usbtask)
root     26   0.0   0.0     0    12  ??  DL     1Jan70     0:00.07  (usb1)
root     27   0.0   0.0     0    12  ??  DL     1Jan70     0:00.08  (usb2)
root    340   0.0   0.1  1124   280  ??  S     18Dec02    16:41.11  nfsd: server (nfsd)
root    375   0.0   0.0  1192    12  ??  Ss    18Dec02     0:01.70  /usr/sbin/lpd
daemon  408   0.0   0.0  1136   152  ??  Ss    18Dec02     0:11.41  /usr/sbin/rwhod
root    420   0.0   0.1  2648   308  ??  Ss    18Dec02     0:04.20  /usr/sbin/sshd
root    491   0.0   0.1  2432   368  ??  Ss    18Dec02     0:38.61  /usr/local/sbin/httpd
root    551   0.0   0.0  1336    12  ??  Ss    18Dec02     0:02.71  /usr/sbin/inetd -wW
root    562   0.0   0.0  1252   216  ??  Is    18Dec02     0:15.50  /usr/sbin/cron
root    572   0.0   0.0  1180     8  v2  IWs+   -          0:00.00  /usr/libexec/getty Pc
www     582   0.0   0.0  2432     8  ??  IW     -          0:00.00  /usr/local/sbin/httpd
grog    608   0.0   0.1  1316   720  v0  I     18Dec02     0:00.04  -bash (bash)
root   2600   0.0   0.0  1180     8  v1  IWs+   -          0:00.00  /usr/libexec/getty Pc
root  33069   0.0   0.3  5352  1716  ??  Ss    29Dec02     0:01.30  xterm -name xterm
grog  33081   0.0   0.1  1328   752  p8  Is+   29Dec02     0:00.09  /usr/local/bin/bash

This list is just an excerpt. Even on a freshly booted system, the real list of processes will be much larger, about 50 processes.

We've seen a number of these fields already. The others are:

• USER is the real user ID of the process, the user ID of the person who started it.
• %CPU is an approximate count of the proportion of CPU time that the process has been using in the last few seconds. This is the column to examine if things suddenly get slow.
• %MEM is an approximate indication of the amount of physical memory that the process is using.
• VSZ (virtual size) is the amount of virtual memory that the process is using, measured in kilobytes.
• RSS (resident segment size) is the amount of physical memory currently in use, measured in kilobytes.
• STARTED is the time or date when the process was started.

In addition, a surprising number of processes don't have a controlling terminal. They are daemons and we'll look at them in the next section.

A significant part of the work in a FreeBSD system is performed by daemons. A daemon is not just the BSD mascot described on page 21—it's also a process that goes around in the background and does routine work such as sending mail (sendmail), handling incoming Internet connections (inetd), or starting jobs at particular times (cron).

To quote the Oxford English Dictionary: Demon Also daemon. ME [In form and in sense I, a. L. dcemon (med. L. demon)...] 1a. In ancient Greek mythology (): A supernatural being of a nature intermediate between that of gods and men, an inferior divinity, spirit, genius (including the souls of deceased persons, esp deified heros). Often written dcemon for distinction.

You can recognize daemons in a ps waux listing by the fact that they don't have a controlling terminal—instead you see the characters ?? Each daemon has a man page that describes what it does.

Normally, daemons are started when the system is booted and run until the system is stopped. If you stop one by accident, you can usually restart them. One exception is init, which is responsible for starting other processes. If you kill it, you effectively kill the system. Unlike traditional UNIX systems, FreeBSD does not allow init to be killed.

One of the more useful daemons is cron named after Father Time.cron performs functions at specific times. For example, the system runs the script /etc/periodic/daily every day at 2:00 am, the script /etc/periodic/weekly every Saturday at 3:30 am, and the script /etc/periodic/monthly on the first day of every month at 5:30 am.

To tell cron to perform a function at a particular time, you need a file called a crontab. The system keeps the realcrontab where you can't get at it, but you can keep a copy. It's a good idea to call it crontab as well.

Let's look at the format of the default systemcrontab, located in /etc/crontab:

# /etc/crontab - root's crontab for FreeBSD
#
# $Id: crontab, v 1.10 1995/05/27 01:55:21 ache Exp $
# From: Id: crontab, v 1.6 1993/05/31 02:03:57 cgd Exp
#
SHELL=/bin/sh
PATH=/etc: /bin: /sbin: /usr/bin: /usr/sbin
HOME=/var/log
#
# minute  hour  mday  month  wday  who   command
#
*/5       *     *     *      *     root  /usr/libexec/atrun
#
# rotate log files every hour, if necessary
#0        *     *     *      *     root  /usr/bin/newsyslog
#
#do daily/weekly/monthly maintenance
0         2     *     *      *     root  /etc/daily 2>&1
30        3     *     *      6     root  /etc/weekly 2>&1
30        5     1     *      *     root  /etc/monthly 2>&1
#
#time zone change adjustment for wall cmos clock,
#See adjkerntz (8) for details.
1, 31     0-4   *     *      *     root  /sbin/adjkerntz -a

As usual, lines starting with # are comments. The others have seven fields. The first five fields specify the minute, the hour, the day of the month, the month, and the day of the week on which an action should be performed. The character * means "every." Thus, 0 2*** (for /etc/daily) means "0 minutes, 2 o'clock (on the 24 hour clock), every day of the month, every month, every weekday."

Field number six is special: it only exists in /etc/crontab, not in private crontabs. It specifies the user for whom the operation should be performed. When you write your own crontab file, don't use this field.