1.1.1 A Word on GNU

The Linux kernel project began as a solo endeavor by Linus Torvalds in 1991, but as Isaac Newton once said, “If I have seen further, it is by standing on the shoulders of giants.” When Linus Torvalds began the kernel the Free Software Foundation had already established the idea of collaborative software. They entitled their effort GNU, a recursive acronym that means simply “GNU's Not Unix”. GNU software ran atop the Linux kernel from day 1. Their compiler gcc was used to compile the kernel. Today many GNU tools from gcc to gnutar are still at the basis of every major Linux distribution. For this reason many of the Free Software Foundation's proponents fervently state that their work should be given the same credit as the Linux kernel. They strongly suggest that all Linux distributions should refer to themselves as GNU/Linux distributions.

This is the topic of many flamewars, surpassed only by the ancient vi versus emacs holy war. The purpose of this book is not to fan the fires of this heated discussion, but rather to clarify the terminology for neophytes. When one sees GNU/Linux it means a Linux distribution. When one sees Linux they can either be referring to the kernel, or to a distribution. It can be rather confusing. Typically the term GNU/Linux isn't used because it's a mouth full.

2.1.1 man

The man command (short for “manual”) is the traditional form of online documentation in Unix and Linux operating systems. Comprised of specially formatted files, the “man pages”, are written for the vast majority of commands and are distributed with the software itself. Executing man somecommand will display the man page for (naturally) the command specified, in our example this would be the imaginary program somecommand.

As you might imagine, the amount of man pages can quickly add up, becoming overly confusing and seriously complicated, even for an advanced user. So, for this reason, man pages are grouped into enumerated sections. This system has been around for a very long time; enough so that you will often see commands, programs, and even programming library functions referred to with their man section number.

For example:

You might see a reference to man(1). The numbering tells you that “man” is documented in section 1 (user commands); you can specify that you want the section 1 man page for “man” with the command man 1 man. Specifying the section that man should look in is useful in the case of multiple items with the same name.

In addition to man(1), there are the commands whatis(1) and apropos(1) available to you, whose shared purpose is to make it easier to find information in the man system.

The command whatis gives a very brief description of system commands, somewhat in the style of a pocket command reference.

Example:

% whatis whatis
whatis (1)  - search the whatis database for complete words

The command apropos is used to search for a man page containing a given keyword.

Example:

% apropos wav
cdda2wav    (1)  - a sampling utility that dumps CD audio data into wav sound files
netwave_cs  (4)  - Xircom Creditcard Netwave device driver
oggdec      (1)  - simple decoder, Ogg Vorbis file to PCM audio file (WAV or RAW)
wavelan     (4)  - AT&T GIS WaveLAN ISA device driver
wavelan_cs  (4)  - AT&T GIS WaveLAN PCMCIA device driver
wvlan_cs    (4)  - Lucent WaveLAN/IEEE 802.11 device driver

If you'd like further information on any of these commands, read their man pages for the details. ;)

2.1.2 The /usr/doc Directory

The source for most packages that we build comes with some sort of documentation: README files, usage instructions, license files, etc. Any sort of documentation that comes with the source is included and installed on your system in the /usr/doc directory. Each program will (usually) install its own documentation in the order of:

/usr/doc/$program-$version

Where $program is the name of the program you are wanting to read about, and $version is (obviously) the appropriate version of software package installed on your system.

For example, to read the documentation for the command man(1) you would want to cd to:

% cd /usr/doc/man-$version

If reading the appropriate man page(s) doesn't provide you with enough information, or address what you're looking for in particular, the /usr/doc directory should be your next stop.

2.1.3 HOWTOs and mini-HOWTOs

It is in the truest spirit of the Open Source community that brings us to the HOWTO/mini-HOWTO collection. These files are exactly what they sound like - documents and guides describing how to do stuff. If you installed the HOWTO collection, the HOWTOs will be installed to /usr/doc/Linux-HOWTOs and the mini-HOWTOs to /usr/doc/Linux-mini-HOWTOs.

Also included in the same package series is a collection of FAQs, which is an acronym which stands for

These documents are written in a “Question and answer” style for (surprise) Frequently Asked Questions. The FAQs can often be a very useful place to look if you're just looking for a “Quick Fix” to something. If you decide to install the FAQs during setup, you will find them installed to the /usr/doc/Linux-FAQs directory.

These files are well worth reading whenever you're not quite sure how to proceed with something. They cover an amazing range of topics, more often than not in a surprisingly detailed manner. Good stuff!

2.2.1 The Official Website and Help Forums

The Official Slackware Website

The Official Slackware Linux website is sometimes out of date, but still contains information relevant to the latest Slackware versions. At one time an active help forum existed there before a horde of trolls, troublemakers, and whiners descended on the forum. Maintaining the forum was beginning to be too much work, and so Pat shut it down. One can find that old forum back up and running complete with searchable archives of the old data at http://www.userlocal.com/phorum/.

After the forums were taken down on http://slackware.com, several other sites sprang up that offered forum support for Slackware. After much thought, Pat chose to endorse www.linuxquestions.org as the official forum for Slackware Linux.

2.2.2 E-mail Support

Everyone who purchases an official CD set is entitled to free installation support via e-mail from the developer. That having been said, please keep in mind that we, the developers, (and a vast majority of users) of Slackware are of “The Old School”. That means that we prefer to help those who have a sincere interest and are willing to help themselves in the process. We will always do our best to help everyone who emails us with support questions. However, Please check your documentation and the website (especially the FAQs and maybe some of the forums listed below) before e-mailing. You may get a faster answer that way, and the less e-mail we have to answer, obviously the sooner we will be of assistance to those that need it.

The e-mail address for technical support is: support@slackware.com. Other e-mail addresses and contact information are listed on the website.

2.2.3 Non-Official Websites and Help Forums

3.1.1 The Official Disc and Box Sets

The official Slackware Linux CD set is available from Slackware Linux, Inc. The CD set consists of 4 discs. The first disk contains all the software needed for a basic server install, and the X window system. The second cd is a “live” cd; that is, a bootable cd that installs into RAM and gives you a temporary installation to play around with or do a data or machine rescue. This cd also contains a few packages such as the KDE and GNOME desktop environments. A few other goodies are included on the second cd including many non-vital packages in the “extra” folder. The third and fourth CDs contain the source code to all of Slackware, along with the original edition of this book.

One may also purchase a boxed set that includes the 4 discs and a copy of this book, as well as lots of neat Slackware gear to show off your geek pride. CD subscriptions are available at a reduced rate also.

The preferred method for shopping for Slackware merchandise is online at the Slackware store.

http://store.slackware.com

You can also call or e-mail your order in.

3.1.2 Via the Internet

Slackware Linux is also freely available over the Internet. You may email in your support questions, but higher priority will be given to those who have purchased the official CD set. With that said, we get a lot of e-mails and our time is rather limited. Before e-mailing for support consider reading Chapter 2 first.

The official Slackware Linux Project website is located at:

http://www.slackware.com/

The primary FTP location for Slackware Linux is:

ftp://ftp.slackware.com/pub/slackware/

Bear in mind that our ftp site, while open for general use, does not have unlimited bandwidth. Please consider using a mirror near you to download Slackware. An incomplete list of mirrors can be found on our site at http://www.slackware.com/getslack.

3.2.1 The Software Series

For reasons of simplicity, Slackware has historically been divided into software series. Once called “disk sets” because they were designed for floppy-based installation, the software series are now used primarily to categorize the packages included in Slackware. Today, floppy installation is no longer possible.

The following is a brief description of each software series.

3.2.2 Installation Methods

3.2.3 Boot Disk

The boot disk is the floppy you actually boot from to begin the installation. It contains a compressed kernel image which is used to control the hardware during installation. Therefore, it is very much required (unless you're booting from CD, as is discussed in the section called CD-ROM). The boot disks are located in the bootdisks/ directory in the distribution tree.

There are more Slackware boot disks than you can shake a stick at (which is to say about 16). A complete list of boot disks, with a description of each, is available in the Slackware distribution tree in the file bootdisks/README.TXT. However, most people are able to use the bare.i (for IDE devices) or scsi.s (for SCSI devices) boot disk image.

See Section 3.2.6 for instructions on making a disk from an image.

After booting, you will be prompted to insert the root disk. We recommend that you just humor the boot disk and play along.

3.2.4 Root Disk

The root disks contain the setup program and a filesystem which is used during installation. They are also required. The root disk images are located in the directory rootdisks in the distribution tree. You'll have to make two root disks from the install.1 and install.2 images. Here you can also find the network.dsk, pcmcia.dsk, rescue.dsk, and sbootmgr.dsk disks.

3.2.5 Supplemental Disk

A supplemental disk is needed if you are performing an NFS install or installing to a system with PCMCIA devices. Supplemental disks are in the rootdsks directory in the distribution tree, with the filenames network.dsk and pcmcia.dsk. Recently other supplemental disks such as rescue.dsk and sbootmgr.dsk have been added. The rescue disk is a small floppy root image that runs in a 4MB RAM drive. It includes some basic networking utilities and the vi editor for quick fixes on busted machines. The sbootmgr.dsk disk is used to boot other devices. Boot off this disk if your bootable CD-ROM drive doesn't want to boot the Slackware CDs. It will prompt you for different things to boot and may offer a convenient way to work around a buggy BIOS.

The root disk will instruct you on the use of supplemental disks when it is loaded.

3.2.6 Making the Disks

Once you've selected a boot disk image, you need to put it on a floppy. The process is slightly different depending on which operating system you're using to make the disks. If you're running Linux (or pretty much any Unix-like OS) you'll need to use the dd(1) command. Assuming bare.i is your disk image file and your floppy drive is /dev/fd0, the command to make a bare.i floppy is:

% dd if=bare.i of=/dev/fd0

If you're running a Microsoft OS, you'll need to use the RAWRITE.EXE program, which is included in the distribution tree in the same directories as the floppy images. Again assuming that bare.i is your disk image file and your floppy drive is A:, open a DOS prompt and type the following:

C:\ rawrite a: bare.i

3.4.1 HELP

If this is your first time installing Slackware, you might want to take a look at the help screen. It will give a description of each part of setup (much like the one we're writing now, but less involved) and instructions for navigating the rest of the install.

3.4.2 KEYMAP

If you require a keymap other than the United States “qwerty” layout, you may want to take a look at this section. It offers a number of alternate layouts for your keyboarding enjoyment.

3.4.3 ADDSWAP

If you created a swap partition (back in Section 3.3), this section will allow you to enable it. It will autodetect and display the swap partitions on your hard drive, allowing you to select one to format and enable.

3.4.4 TARGET

The target section is where your other (non-swap) partitions are formatted and mapped to filesystem mount points. A list of the partitions on your hard disk will be displayed. For each partition, you will be given the option of whether to format that partition or not. Depending on the kernel used, you can choose between reiserfs (the default), ext3, ext2, jfs, and xfs. Most people use either reiserfs or ext3. In the near future we may see support for reiserfs4 slip in.

The first option in the target section is the selection of a partition on which to install your root (/) filesystem. After that, you will be able to map other partitions to filesystems as you choose. (For instance, you may want your third partition, say /dev/hda3, to be your home filesystem. This is just an example; map the partitions as you see fit.)

3.4.5 SOURCE

The source section is where you select the source media from which you are installing Slackware. Currently there are four sources to choose from. These are CD-ROM, NFS, or a premounted directory.

The CD-ROM selection enables a CD-ROM based installation. It will offer the option of scanning for a CD-ROM drive or displaying a list from which you can pick your drive type. Make sure you have the Slackware CD in your drive before allowing it to scan.

The NFS selection prompts for your network information and the network information for your NFS server. The NFS server must be set up in advance. Also note that you cannot use hostnames, you must use the IP addresses for both your machine and the NFS server (there is no name resolver on the setup disk). Naturally you must have used the network.dsk floppy to add support for your network controller.

The premounted directory offers the most flexibility. You can use this method to install from things such as Jaz disks, NFS mounts over PLIP, and FAT filesystems. Mount the filesystem to a location of your choosing before running setup, then specify that location here.

3.4.6 SELECT

The select option allows you to select the software series that you wish to install. These series are described in Section 3.2.1. Please note that you must install the A series to have a working base system. All other series are optional.

3.4.7 INSTALL

Assuming that you have gone through the “target”, “source”, and “select” options, the install option will allow you to select packages from your chosen software series. If not, it will prompt you to go back and complete the other sections of the setup program. This option allows you to select from six different installation methods: full, newbie, menu, expert, custom, and tag path.

The full option will install every package from all the software series that you chose in the “select” section. There is no further prompting. This is the easiest installation method, since you do not need to make any decisions on the actual packages to install. Of course, this option also takes up the most hard drive space.

The next option is newbie. This option installs all of the required packages in the selected series. For all other packages, it offers a prompt where you can select “Yes”, “No”, or “Skip”. Yes and No do the obvious, while Skip will go ahead to the next software series. Additionally, you will see a description and size requirement for each package to help you decide if you need it. We recommend this option for new users, as it ensures that you get all the required packages installed. However, it is a little slow because of the prompting.

Menu is a faster and more advanced version of the newbie option. For each series, a menu is displayed, from which you can select all the non-required packages you want to install. Required packages are not displayed on this menu.

For the more advanced user, install offers the expert option. This allows you complete control over what packages get installed. You can deselect packages that are absolutely required, resulting in a broken system. On the other hand, you can control exactly what goes onto your system. Simply select the packages from each series that you want installed. This is not recommended for the new user, as it is quite easy to shoot yourself in the foot.

The custom and tag path options are also for advanced users. These options allow you to install based upon custom tag files that you created in the distribution tree. This is useful for installing to large numbers of machines fairly quickly. For more information on using tag files, see Section 18.4.

After selecting your installation method, one of a few things will happen. If you selected full or menu, a menu screen will appear, allowing you to select the packages to be installed. If you selected full, packages will immediately start getting installed to the target. If you selected newbie, packages will be installed until an optional package is reached.

Note that it is possible to run out of space while installing. If you selected too many packages for the amount of free space on the target device, you will have problems. The safest thing to do is to select some software and add more later, if you need it. This can easily be done using Slackware's package management tools. For this information, see Chapter 18.

3.4.8 CONFIGURE

The configure section allows you to do some basic system configuration, now that the packages have been installed. What you see here depends in large part upon which software you have installed. You will, however, always see the following:

4.1.1 File System Layout

The first noticeable difference between Slackware Linux and a DOS or Windows system is the filesystem. For starters, we do not use drive letters to denote different partitions. Under Linux, there is one main directory. You can relate this to the C: drive under DOS. Each partition on your system is mounted to a directory on the main directory. It's kind of like an ever-expanding hard disk.

We call the main directory the root directory, and it's denoted with a single slash (/). This concept may seem strange, but it actually makes life easy for you when you want to add more space. For example, let's say you run out of space on the drive that has /home on it. Most people install Slackware and make one big root drive. Well, since a partition can be mounted to any directory, you can simply go to the store and pick up a new hard drive and mount it to /home. You've now grafted on some more space to your system. And all without having to move many things around.

Below, you will find descriptions of the major top level directories under Slackware.

You should now have a good feel for which directories contain what on the filesystem. More detailed information about the filesystem layout is available in the hier(7) man page. The next section will help you find specific files easily, so you don't have to do it by hand.

4.1.2 Finding Files

You now know what each major directory holds, but it still doesn't really help you find things. I mean, you could go looking through directories, but there are quicker ways. There are four main file search commands available in Slackware.

%  which bash
/bin/bash

%  whereis bash
bash: /bin/bash /usr/bin/bash /usr/man/man1/bash.1.gz

%  find / -name xinitrc
/var/X11R6/lib/xinit/xinitrc

%  slocate xinitrc   # we don't have to go to the root
/var/X11R6/lib/xinit/xinitrc
/var/X11R6/lib/xinit/xinitrc.fvwm2
/var/X11R6/lib/xinit/xinitrc.openwin
/var/X11R6/lib/xinit/xinitrc.twm

4.1.3 The /etc/rc.d Directory

The system initialization files are stored in the /etc/rc.d directory. Slackware uses the BSD-style layout for its initialization files as opposed to System V init scripts, which tend to make configuration changes much more difficult without using a program specifically designed for that purpose. In BSD-init scripts, each runlevel is given a single rc file. In System V, each runlevel is given its own directory, each containing numerous init scripts. This provides an organized structure that is easy to maintain.

There are several categories of initialization files. These are system startup, runlevels, network initialization, and System V compatibility. As per tradition, we'll lump everything else into another category.

4.2.1 The /kernels Directory on the Slackware CD-ROM

The precompiled Slackware kernels are available in the /kernels directory on the Slackware CD-ROM or on the FTP site in the main Slackware directory. The available kernels change as new releases are made, so the documentation in that directory is always the authoritative source. The /kernels directory has subdirectories for each kernel available. The subdirectories have the same name as their accompanying boot disk. In each subdirectory you will find the following files:

To use a kernel, copy the System.map and config files to your /boot directory and copy the kernel image to /boot/vmlinuz. Run /sbin/lilo(8) to install LILO for the new kernel, and then reboot your system. That's all there is to installing a new kernel.

The kernels that end with a .i are IDE kernels. That is, they include no SCSI support in the base kernel. The kernels that end with .s are SCSI kernels. They include all the IDE support in .i kernels, plus SCSI support.

4.2.2 Compiling a Kernel from Source

The question “Should I compile a kernel for my system?” is often asked by new users. The answer is a definite maybe. There are few instances where you will need to compile a kernel specific to your system. Most users can use a precompiled kernel and the loadable kernel modules to achieve a fully working system. You will want to compile a kernel for your system if you are upgrading kernel versions to one that we do not currently offer in Slackware, or if you have patched the kernel source to get special device support that is not in the native kernel source. Anyone with an SMP system will definitely want to compile a kernel with SMP support. Also, many users find a custom compiled kernel runs much faster on their machine. You may find it useful to compile the kernel with optimizations for the specific processor in your machine.

Building your own kernel is not that hard. The first step is to make sure you have the kernel source installed on your system. Make sure that you installed the packages from the K series during the installation. You will also want to make sure you have the D series installed, specifically the C compiler, GNU make, and GNU binutils. In general, it's a good idea to have the entire D series installed if you plan on doing any kind of development. You can also download the latest kernel source from http://www.kernel.org/mirrors.

% su -
Password:
# cd /usr/src/linux

# make mrproper

# make config           (text-based Q&A version)
# make menuconfig       (menu driven, text-based version)
# make xconfig          (X-based version, make sure you are in X first)

# make dep
# make clean

# make bzImage

# make modules

# mv /boot/vmlinuz /boot/vmlinuz.old
# cat arch/i386/boot/bzImage > /vmlinuz
# mv /boot/System.map /boot/System.map.old
# cp System.map /boot/System.map
# make modules_install

# make bzImage V=1

4.2.3 Using Kernel Modules

Kernel modules are another name for device drivers that can be inserted into a running kernel. They allow you to extend the hardware supported by your kernel without needing to pick another kernel or compile one yourself.

Modules can also be loaded and unloaded at any time, even when the system is running. This makes upgrading specific drivers easy for system administrators. A new module can be compiled, the old one removed, and the new one loaded, all without rebooting the machine.

Modules are stored in the /lib/modules/kernel version directory on your system. They can be loaded at boot time through the rc.modules file. This file is very well commented and offers examples for major hardware components. To see a list of modules that are currently active, use the lsmod(1) command:

# lsmod
Module                  Size  Used by
parport_pc              7220   0 
parport                 7844   0  [parport_pc]

You can see here that I only have the parallel port module loaded. To remove a module, you use the rmmod(1) command. Modules can be loaded by the modprobe(1) or insmod(1) command. modprobe is usually safer because it will load any modules that the one you're trying to load depends on.

A lot of users never have to load or unload modules by hand. They use the kernel autoloader for module management. By default, Slackware includes kmod in its kernels. kmod is a kernel option that enables the kernel to automatically load modules as they are requested. For more information on kmod and how it is configured, see /usr/src/linux/Documentation/kmod.txt. You'll have needed to have the kernel source package, or downloaded kernel source from