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| author |   Patrick J Volkerding <volkerdi@slackware.com> | 2009-08-26 10:00:38 -0500 |
|---|---|---|
| committer |   Eric Hameleers <alien@slackware.com> | 2018-05-31 22:41:17 +0200 |
| commit | 5a12e7c134274dba706667107d10d231517d3e05 (patch) | |
| tree | 55718d5acb710fde798d9f38d0bbaf594ed4b296 /slackbook/html/system-configuration.html | |
| download | current-5a12e7c134274dba706667107d10d231517d3e05.tar.gz current-5a12e7c134274dba706667107d10d231517d3e05.tar.xz | |
Slackware 13.0slackware-13.0
Wed Aug 26 10:00:38 CDT 2009
Slackware 13.0 x86_64 is released as stable! Thanks to everyone who
helped make this release possible -- see the RELEASE_NOTES for the
credits. The ISOs are off to the replicator. This time it will be a
6 CD-ROM 32-bit set and a dual-sided 32-bit/64-bit x86/x86_64 DVD.
We're taking pre-orders now at store.slackware.com. Please consider
picking up a copy to help support the project. Once again, thanks to
the entire Slackware community for all the help testing and fixing
things and offering suggestions during this development cycle.
As always, have fun and enjoy! -P.
Diffstat (limited to 'slackbook/html/system-configuration.html')
| -rw-r--r-- | slackbook/html/system-configuration.html | 589 |
1 files changed, 589 insertions, 0 deletions
diff --git a/slackbook/html/system-configuration.html b/slackbook/html/system-configuration.html new file mode 100644 index 000000000..2c88375a6 --- /dev/null +++ b/slackbook/html/system-configuration.html @@ -0,0 +1,589 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" + "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml"> +<head> +<meta name="generator" content="HTML Tidy, see www.w3.org" /> +<title>System Configuration</title> +<meta name="GENERATOR" content="Modular DocBook HTML Stylesheet Version 1.7" /> +<link rel="HOME" title="Slackware Linux Essentials" href="index.html" /> +<link rel="PREVIOUS" title="The setup Program" href="installation-setup.html" /> +<link rel="NEXT" title="Selecting a Kernel" href="system-configuration-kernel.html" /> +<link rel="STYLESHEET" type="text/css" href="docbook.css" /> +<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> +</head> +<body class="CHAPTER" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#840084" +alink="#0000FF"> +<div class="NAVHEADER"> +<table summary="Header navigation table" width="100%" border="0" cellpadding="0" +cellspacing="0"> +<tr> +<th colspan="3" align="center">Slackware Linux Essentials</th> +</tr> + +<tr> +<td width="10%" align="left" valign="bottom"><a href="installation-setup.html" +accesskey="P">Prev</a></td> +<td width="80%" align="center" valign="bottom"></td> +<td width="10%" align="right" valign="bottom"><a href="system-configuration-kernel.html" +accesskey="N">Next</a></td> +</tr> +</table> + +<hr align="LEFT" width="100%" /> +</div> + +<div class="CHAPTER"> +<h1><a id="SYSTEM-CONFIGURATION" name="SYSTEM-CONFIGURATION"></a>Chapter 4 System +Configuration</h1> + +<div class="TOC"> +<dl> +<dt><b>Table of Contents</b></dt> + +<dt>4.1 <a href="system-configuration.html#SYSTEM-CONFIGURATION-OVERVIEW">System +Overview</a></dt> + +<dt>4.2 <a href="system-configuration-kernel.html">Selecting a Kernel</a></dt> +</dl> +</div> + +<p>Before you can configure the more advanced parts of your system, it's a good idea to +learn how the system is organized and what commands can be used to search for files and +programs. It's also good to know if you need to compile a custom kernel and what the +steps for doing that are. This chapter will familiarize you with system organization and +configuration files. Then, you can move on to configuring the more advanced parts of the +system.</p> + +<div class="SECT1"> +<h1 class="SECT1"><a id="SYSTEM-CONFIGURATION-OVERVIEW" +name="SYSTEM-CONFIGURATION-OVERVIEW">4.1 System Overview</a></h1> + +<p>It's important to understand how a Linux system is put together before diving into the +various configuration aspects. A Linux system is significantly different from a DOS, +Windows, or Macintosh system (with the exception of the Unix-based Mac OS X), but these +sections will help you get acquainted with the layout so that you can easily configure +your system to meet your needs.</p> + +<div class="SECT2"> +<h2 class="SECT2"><a id="SYSTEM-CONFIGURATION-LAYOUT" +name="SYSTEM-CONFIGURATION-LAYOUT">4.1.1 File System Layout</a></h2> + +<p>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 <tt +class="DEVICENAME">C:</tt> 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.</p> + +<p>We call the main directory the root directory, and it's denoted with a single slash +(<tt class="FILENAME">/</tt>). 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 <tt class="FILENAME">/home</tt> 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 +<tt class="FILENAME">/home</tt>. You've now grafted on some more space to your system. +And all without having to move many things around.</p> + +<p>Below, you will find descriptions of the major top level directories under +Slackware.</p> + +<div class="VARIABLELIST"> +<dl> +<dt><tt class="FILENAME">bin</tt></dt> + +<dd> +<p>Essential user programs are stored here. These represent the bare minimum set of +programs required for a user to use the system. Things like the shell and the filesystem +commands (<tt class="COMMAND">ls</tt>, <tt class="COMMAND">cp</tt>, and so on) are stored +here. The <tt class="FILENAME">/bin</tt> directory usually doesn't receive modification +after installation. If it does, it's usually in the form of package upgrades that we +provide.</p> +</dd> + +<dt><tt class="FILENAME">boot</tt></dt> + +<dd> +<p>Files that are used by the Linux Loader (LILO). This directory also receives little +modification after an installation. The kernel is stored here as of Slackware 8.1. In +earlier releases of Slackware, the kernel was simply stored under <tt +class="FILENAME">/</tt> , but common practice is to put the kernel and related files here +to facilitate dual-booting.</p> +</dd> + +<dt><tt class="FILENAME">dev</tt></dt> + +<dd> +<p>Everything in Linux is treated as a file, even hardware devices like serial ports, +hard disks, and scanners. In order to access these devices, a special file called a +device node has to be present. All device nodes are stored in the <tt +class="FILENAME">/dev</tt> directory. You will find this to be true across many Unix-like +operating systems.</p> +</dd> + +<dt><tt class="FILENAME">etc</tt></dt> + +<dd> +<p>This directory holds system configuration files. Everything from the X Window +configuration file, the user database, to the system startup scripts. The system +administrator will become quite familiar with this directory over time.</p> +</dd> + +<dt><tt class="FILENAME">home</tt></dt> + +<dd> +<p>Linux is a multiuser operating system. Each user on the system is given an account and +a unique directory for personal files. This directory is called the user's home +directory. The <tt class="FILENAME">/home</tt> directory is provided as the default +location for user home directories.</p> +</dd> + +<dt><tt class="FILENAME">lib</tt></dt> + +<dd> +<p>System libraries that are required for basic operation are stored here. The C library, +the dynamic loader, the ncurses library, and kernel modules are among the things stored +here.</p> +</dd> + +<dt><tt class="FILENAME">mnt</tt></dt> + +<dd> +<p>This directory contains temporary mount points for working on hard disks or removable +drives. Here you'll find mount points for your CD-ROM and floppy drives.</p> +</dd> + +<dt><tt class="FILENAME">opt</tt></dt> + +<dd> +<p>Optional software packages. The idea behind <tt class="FILENAME">/opt</tt> is that +each software package installs to <tt class="FILENAME">/opt/<var +class="REPLACEABLE">software-package</var></tt>, which makes it easy to remove later. +Slackware distributes some things in <tt class="FILENAME">/opt</tt> (such as KDE in <tt +class="FILENAME">/opt/kde</tt>), but you are free to add anything you want to <tt +class="FILENAME">/opt</tt>.</p> +</dd> + +<dt><tt class="FILENAME">proc</tt></dt> + +<dd> +<p>This is a unique directory. It's not really part of the filesystem, but a virtual +filesystem that provides access to kernel information. Various pieces of information that +the kernel wants you to know are conveyed to you through files in the <tt +class="FILENAME">/proc</tt> directory. You can also send information to the kernel +through some of these files. Try doing <tt class="COMMAND">cat /proc/cpuinfo</tt>.</p> +</dd> + +<dt><tt class="FILENAME">root</tt></dt> + +<dd> +<p>The system administrator is known as <tt class="USERNAME">root</tt> on the system. <tt +class="USERNAME">root</tt>'s home directory is kept in <tt class="FILENAME">/root</tt> +instead of <tt class="FILENAME">/home/root</tt>. The reason is simple. What if <tt +class="FILENAME">/home</tt> was a different partition from <tt class="FILENAME">/</tt> +and it could not be mounted? <tt class="USERNAME">root</tt> would naturally want to log +in and repair the problem. If his home directory was on the damaged filesystem, it would +make it difficult for him to log in.</p> +</dd> + +<dt><tt class="FILENAME">sbin</tt></dt> + +<dd> +<p>Essential programs that are run by <tt class="USERNAME">root</tt> and during the +system bootup process are kept here. Normal users will not run programs in this +directory.</p> +</dd> + +<dt><tt class="FILENAME">tmp</tt></dt> + +<dd> +<p>The temporary storage location. All users have read and write access to this +directory.</p> +</dd> + +<dt><tt class="FILENAME">usr</tt></dt> + +<dd> +<p>This is the big directory on a Linux system. Everything else pretty much goes here, +programs, documentation, the kernel source code, and the X Window system. This is the +directory to which you will most likely be installing programs.</p> +</dd> + +<dt><tt class="FILENAME">var</tt></dt> + +<dd> +<p>System log files, cache data, and program lock files are stored here. This is the +directory for frequently-changing data.</p> +</dd> +</dl> +</div> + +<p>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.</p> +</div> + +<div class="SECT2"> +<h2 class="SECT2"><a id="SYSTEM-CONFIGURATION-FINDING" +name="SYSTEM-CONFIGURATION-FINDING">4.1.2 Finding Files</a></h2> + +<p>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.</p> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1329" name="AEN1329">4.1.2.1 <tt +class="COMMAND">which</tt></a></h3> + +<p>The first is the <tt class="COMMAND">which</tt>(1) command. <tt +class="COMMAND">which</tt> is usually used to locate a program quickly. It just searches +your <tt class="ENVAR">PATH</tt> and returns the first instance it finds and the +directory path to it. Take this example:</p> + +<table border="0" bgcolor="#E0E0E0" width="100%"> +<tr> +<td> +<pre class="SCREEN"> +<samp class="PROMPT">%</samp> <kbd class="USERINPUT">which bash</kbd> +/bin/bash +</pre> +</td> +</tr> +</table> + +<p>From that you see that <tt class="COMMAND">bash</tt> is in the <tt +class="FILENAME">/bin</tt> directory. This is a very limited command for searching, since +it only searches your <tt class="ENVAR">PATH</tt>.</p> +</div> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1347" name="AEN1347">4.1.2.2 <tt +class="COMMAND">whereis</tt></a></h3> + +<p>The <tt class="COMMAND">whereis</tt>(1) command works similar to <tt +class="COMMAND">which</tt>, but can also search for man pages and source files. A <tt +class="COMMAND">whereis</tt> search for <tt class="COMMAND">bash</tt> should return +this:</p> + +<table border="0" bgcolor="#E0E0E0" width="100%"> +<tr> +<td> +<pre class="SCREEN"> +<samp class="PROMPT">%</samp> <kbd class="USERINPUT">whereis bash</kbd> +bash: /bin/bash /usr/bin/bash /usr/man/man1/bash.1.gz +</pre> +</td> +</tr> +</table> + +<p>This command not only told us where the actual program is located, but also where the +online documentation is stored. Still, this command is limited. What if you wanted to +search for a specific configuration file? You can't use <tt class="COMMAND">which</tt> or +<tt class="COMMAND">whereis</tt> for that.</p> +</div> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1363" name="AEN1363">4.1.2.3 <tt +class="COMMAND">find</tt></a></h3> + +<p>The <tt class="COMMAND">find</tt>(1) command allows the user to search the filesystem +with a rich collection of search predicates. Users may specify a search with filename +wildcards, ranges of modification or creation times, or other advanced properties. For +example, to search for the default <tt class="FILENAME">xinitrc</tt> file on the system, +the following command could be used.</p> + +<table border="0" bgcolor="#E0E0E0" width="100%"> +<tr> +<td> +<pre class="SCREEN"> +<samp class="PROMPT">%</samp> <kbd class="USERINPUT">find / -name xinitrc</kbd> +/var/X11R6/lib/xinit/xinitrc +</pre> +</td> +</tr> +</table> + +<p><tt class="COMMAND">find</tt> will take a while to run, since it has to traverse the +entire root directory tree. And if this command is run as a normal user, there will be +permission denied error messages for directories that only <tt class="USERNAME">root</tt> +can see. But <tt class="COMMAND">find</tt> found our file, so that's good. If only it +could be a bit faster...</p> +</div> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1378" name="AEN1378">4.1.2.4 <tt +class="COMMAND">slocate</tt></a></h3> + +<p>The <tt class="COMMAND">slocate</tt>(1) command searches the entire filesystem, just +like the find command can do, but it searches a database instead of the actual +filesystem. The database is set to automatically update every morning, so you have a +somewhat fresh listing of files on your system. You can manually run <tt +class="COMMAND">updatedb</tt>(1) to update the slocate database (before running <tt +class="COMMAND">updatedb</tt> by hand, you must first <tt class="COMMAND">su</tt> to the +<tt class="USERNAME">root</tt> user). Here's an example of <tt +class="COMMAND">slocate</tt> in action:</p> + +<table border="0" bgcolor="#E0E0E0" width="100%"> +<tr> +<td> +<pre class="SCREEN"> +<samp class="PROMPT">%</samp> <kbd +class="USERINPUT">slocate xinitrc</kbd> # 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 +</pre> +</td> +</tr> +</table> + +<p>We got more than what we were looking for, and quickly too. With these commands, you +should be able to find whatever you're looking for on your Linux system.</p> +</div> +</div> + +<div class="SECT2"> +<h2 class="SECT2"><a id="SYSTEM-CONFIGURATION-RCD" name="SYSTEM-CONFIGURATION-RCD">4.1.3 +The <tt class="FILENAME">/etc/rc.d</tt> Directory</a></h2> + +<p>The system initialization files are stored in the <tt class="FILENAME">/etc/rc.d</tt> +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.</p> + +<p>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.</p> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1406" name="AEN1406">4.1.3.1 System Startup</a></h3> + +<p>The first program to run under Slackware besides the Linux kernel is <tt +class="COMMAND">init</tt>(8). This program reads the <tt +class="FILENAME">/etc/inittab</tt>(5) file to see how to run the system. It runs the <tt +class="FILENAME">/etc/rc.d/rc.S</tt> script to prepare the system before going into your +desired runlevel. The <tt class="FILENAME">rc.S</tt> file enables your virtual memory, +mounts your filesystems, cleans up certain log directories, initializes Plug and Play +devices, loads kernel modules, configures PCMCIA devices, sets up serial ports, and runs +System V init scripts (if found). Obviously <tt class="FILENAME">rc.S</tt> has a lot on +its plate, but here are some scripts in <tt class="FILENAME">/etc/rc.d</tt> that <tt +class="FILENAME">rc.S</tt> will call on to complete its work:</p> + +<div class="VARIABLELIST"> +<dl> +<dt><tt class="FILENAME">rc.S</tt></dt> + +<dd> +<p>This is the actual system initialization script.</p> +</dd> + +<dt><tt class="FILENAME">rc.modules</tt></dt> + +<dd> +<p>Loads kernel modules. Things like your network card, PPP support, and other things are +loaded here. If this script finds <tt class="FILENAME">rc.netdevice</tt>, it will run +that as well.</p> +</dd> + +<dt><tt class="FILENAME">rc.pcmcia</tt></dt> + +<dd> +<p>Probes for and configures any PCMCIA devices that you might have on your system. This +is most useful for laptop users, who probably have a PCMCIA modem or network card.</p> +</dd> + +<dt><tt class="FILENAME">rc.serial</tt></dt> + +<dd> +<p>Configures your serial ports by running the appropriate <tt +class="COMMAND">setserial</tt> commands.</p> +</dd> + +<dt><tt class="FILENAME">rc.sysvinit</tt></dt> + +<dd> +<p>Looks for System V init scripts for the desired runlevel and runs them. This is +discussed in more detail below.</p> +</dd> +</dl> +</div> +</div> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1454" name="AEN1454">4.1.3.2 Runlevel Initialization +Scripts</a></h3> + +<p>After system initialization is complete, <tt class="COMMAND">init</tt> moves on to +runlevel initialization. A runlevel describes the state that your machine will be running +in. Sound redundant? Well, the runlevel tells <tt class="COMMAND">init</tt> if you will +be accepting multiuser logins or just a single user, whether or not you want network +services, and if you will be using the X Window System or <tt +class="COMMAND">agetty</tt>(8) to handle logins. The files below define the different +runlevels in Slackware Linux.</p> + +<div class="VARIABLELIST"> +<dl> +<dt><tt class="FILENAME">rc.0</tt></dt> + +<dd> +<p>Halt the system (runlevel 0). By default, this is symlinked to <tt +class="FILENAME">rc.6</tt>.</p> +</dd> + +<dt><tt class="FILENAME">rc.4</tt></dt> + +<dd> +<p>Multiuser startup (runlevel 4), but in X11 with KDM, GDM, or XDM as the login +manager.</p> +</dd> + +<dt><tt class="FILENAME">rc.6</tt></dt> + +<dd> +<p>Reboot the system (runlevel 6).</p> +</dd> + +<dt><tt class="FILENAME">rc.K</tt></dt> + +<dd> +<p>Startup in single user mode (runlevel 1).</p> +</dd> + +<dt><tt class="FILENAME">rc.M</tt></dt> + +<dd> +<p>Multiuser mode (runlevels 2 and 3), but with the standard text-based login. This is +the default runlevel in Slackware.</p> +</dd> +</dl> +</div> +</div> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1493" name="AEN1493">4.1.3.3 Network Initialization</a></h3> + +<p>Runlevels 2, 3, and 4 will start up the network services. The following files are +responsible for the network initialization:</p> + +<div class="VARIABLELIST"> +<dl> +<dt><tt class="FILENAME">rc.inet1</tt></dt> + +<dd> +<p>Created by <tt class="COMMAND">netconfig</tt>, this file is responsible for +configuring the actual network interface.</p> +</dd> + +<dt><tt class="FILENAME">rc.inet2</tt></dt> + +<dd> +<p>Runs after <tt class="FILENAME">rc.inet1</tt> and starts up basic network +services.</p> +</dd> + +<dt><tt class="FILENAME">rc.atalk</tt></dt> + +<dd> +<p>Starts up AppleTalk services.</p> +</dd> + +<dt><tt class="FILENAME">rc.httpd</tt></dt> + +<dd> +<p>Starts up the Apache web server. Like a few other rc scripts, this one can also be +used to stop and restart a service. <tt class="FILENAME">rc.httpd</tt> takes arguments of +stop, start, or restart. </p> +</dd> + +<dt><tt class="FILENAME">rc.news</tt></dt> + +<dd> +<p>Starts up the news server.</p> +</dd> +</dl> +</div> +</div> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1534" name="AEN1534">4.1.3.4 System V Compatibility</a></h3> + +<p>System V init compatibility was introduced in Slackware 7.0. Many other Linux +distributions make use of this style instead of the BSD style. Basically each runlevel is +given a subdirectory for init scripts, whereas BSD style gives one init script to each +runlevel.</p> + +<p>The <tt class="FILENAME">rc.sysvinit</tt> script will search for any System V init +scripts you have in <tt class="FILENAME">/etc/rc.d</tt> and run them, if the runlevel is +appropriate. This is useful for certain commercial software packages that install System +V init scripts</p> +</div> + +<div class="SECT3"> +<h3 class="SECT3"><a id="AEN1546" name="AEN1546">4.1.3.5 Other Files</a></h3> + +<p>The scripts described below are the other system initialization scripts. They are +typically run from one of the major scripts above, so all you need to do is edit the +contents.</p> + +<div class="VARIABLELIST"> +<dl> +<dt><tt class="FILENAME">rc.gpm</tt></dt> + +<dd> +<p>Starts up general purpose mouse services. Allows you to copy and paste at the Linux +console. Occasionally, gpm will cause problems with the mouse when it is used under X +windows. If you experience problems with the mouse under X, try taking away the +executable permission from this file and stopping the gpm server.</p> +</dd> + +<dt><tt class="FILENAME">rc.font</tt></dt> + +<dd> +<p>Loads the custom screen font for the console.</p> +</dd> + +<dt><tt class="FILENAME">rc.local</tt></dt> + +<dd> +<p>Contains any specific startup commands for your system. This is empty after a fresh +install, as it is reserved for local administrators. This script is run after all other +initialization has taken place.</p> +</dd> +</dl> +</div> + +<p>To enable a script, all you need to do is add the execute permissions to it with the +<tt class="COMMAND">chmod</tt> command. To disable a script, remove the execute +permissions from it. For more information about <tt class="COMMAND">chmod</tt>, see <a +href="filesystem-structure-permissions.html">Section 9.2</a>.</p> +</div> +</div> +</div> +</div> + +<div class="NAVFOOTER"> +<hr align="LEFT" width="100%" /> +<table summary="Footer navigation table" width="100%" border="0" cellpadding="0" +cellspacing="0"> +<tr> +<td width="33%" align="left" valign="top"><a href="installation-setup.html" +accesskey="P">Prev</a></td> +<td width="34%" align="center" valign="top"><a href="index.html" +accesskey="H">Home</a></td> +<td width="33%" align="right" valign="top"><a href="system-configuration-kernel.html" +accesskey="N">Next</a></td> +</tr> + +<tr> +<td width="33%" align="left" valign="top">The <tt class="COMMAND">setup</tt> Program</td> +<td width="34%" align="center" valign="top"> </td> +<td width="33%" align="right" valign="top">Selecting a Kernel</td> +</tr> +</table> +</div> +</body> +</html> + |