source: chapter07/usage.xml@ bf58c1e

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Rewrite and reorganize Chapter 7.
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1<?xml version="1.0" encoding="ISO-8859-1"?>
2<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
4 <!ENTITY % general-entities SYSTEM "../general.ent">
5 <!ENTITY site SYSTEM "../appendices/rc.site.script">
6 %general-entities;
7]>
8
9<sect1 id="ch-scripts-usage">
10 <?dbhtml filename="usage.html"?>
11
12 <title>System V Bootscript Usage and Configuration</title>
13
14 <indexterm zone="ch-scripts-usage">
15 <primary sortas="a-Bootscripts">Bootscripts</primary>
16 <secondary>usage</secondary>
17 </indexterm>
18
19 <sect2>
20 <title>How Do the System V Bootscripts Work?</title>
21
22 <para>Linux uses a special booting facility named SysVinit that is based on a
23 concept of <emphasis>run-levels</emphasis>. It can be quite different from one
24 system to another, so it cannot be assumed that because things worked in one
25 particular Linux distribution, they should work the same in LFS too. LFS has its
26 own way of doing things, but it respects generally accepted standards.</para>
27
28 <para>SysVinit (which will be referred to as <quote>init</quote> from now on)
29 works using a run-levels scheme. There are seven (numbered 0 to 6) run-levels
30 (actually, there are more run-levels, but they are for special cases and are
31 generally not used. See <filename>init(8)</filename> for more details), and
32 each one of those corresponds to the actions the computer is supposed to
33 perform when it starts up. The default run-level is 3. Here are the
34 descriptions of the different run-levels as they are implemented:</para>
35
36<literallayout>0: halt the computer
371: single-user mode
382: multi-user mode without networking
393: multi-user mode with networking
404: reserved for customization, otherwise does the same as 3
415: same as 4, it is usually used for GUI login (like X's <command>xdm</command> or KDE's <command>kdm</command>)
426: reboot the computer</literallayout>
43
44 </sect2>
45
46 <sect2 id="conf-sysvinit" role="configuration">
47 <title>Configuring Sysvinit</title>
48
49 <indexterm zone="conf-sysvinit">
50 <primary sortas="a-Sysvinit">Sysvinit</primary>
51 <secondary>configuring</secondary>
52 </indexterm>
53
54 <indexterm zone="conf-sysvinit">
55 <primary sortas="e-/etc/inittab">/etc/inittab</primary>
56 </indexterm>
57
58 <para>During the kernel initialization, the first program that is run
59 is either specified on the command line or, by default
60 <command>init</command>. This program reads the initialization file
61 <filename>/etc/inittab</filename>. Create this file with:</para>
62
63<screen><userinput>cat &gt; /etc/inittab &lt;&lt; "EOF"
64<literal># Begin /etc/inittab
65
66id:3:initdefault:
67
68si::sysinit:/etc/rc.d/init.d/rc S
69
70l0:0:wait:/etc/rc.d/init.d/rc 0
71l1:S1:wait:/etc/rc.d/init.d/rc 1
72l2:2:wait:/etc/rc.d/init.d/rc 2
73l3:3:wait:/etc/rc.d/init.d/rc 3
74l4:4:wait:/etc/rc.d/init.d/rc 4
75l5:5:wait:/etc/rc.d/init.d/rc 5
76l6:6:wait:/etc/rc.d/init.d/rc 6
77
78ca:12345:ctrlaltdel:/sbin/shutdown -t1 -a -r now
79
80su:S016:once:/sbin/sulogin
81
821:2345:respawn:/sbin/agetty --noclear tty1 9600
832:2345:respawn:/sbin/agetty tty2 9600
843:2345:respawn:/sbin/agetty tty3 9600
854:2345:respawn:/sbin/agetty tty4 9600
865:2345:respawn:/sbin/agetty tty5 9600
876:2345:respawn:/sbin/agetty tty6 9600
88
89# End /etc/inittab</literal>
90EOF</userinput></screen>
91
92 <para>An explanation of this initialization file is in the man page for
93 <emphasis>inittab</emphasis>. For LFS, the key command that is run is
94 <command>rc</command>. The intialization file above will instruct
95 <command>rc</command> to run all the scripts starting with an S in the
96 <filename class="directory">/etc/rc.d/rcS.d</filename> directory
97 followed by all the scripts starting with an S in the <filename
98 class="directory">/etc/rc.d/rc?.d</filename> directory where the question
99 mark is specified by the initdefault value.</para>
100
101 <para>As a convenience, the <command>rc</command> script reads a library of
102 functions in <filename class="directory">/lib/lsb/init-functions</filename>.
103 This library also reads an optional configuration file,
104 <filename>/etc/sysconfig/rc.site</filename>. Any of the system
105 configuration file parameters described in subsequent sections can be
106 alternatively placed in this file allowing consolidation of all system
107 parameters in this one file.</para>
108
109 <para>As a debugging convenience, the functions script also logs all output
110 to <filename>/run/var/bootlog</filename>. Since the <filename
111 class="directory">/run</filename> directory is a tmpfs, this file is not
112 persistent across boots, however it is appended to the more permanent file
113 <filename>/var/log/boot.log</filename> at the end of the boot process.</para>
114
115 <sect3 id="init-levels" >
116 <title>Changing Run Levels</title>
117
118 <para>Changing run-levels is done with <command>init
119 <replaceable>&lt;runlevel&gt;</replaceable></command>, where
120 <replaceable>&lt;runlevel&gt;</replaceable> is the target run-level. For example, to
121 reboot the computer, a user could issue the <command>init 6</command> command,
122 which is an alias for the <command>reboot</command> command. Likewise,
123 <command>init 0</command> is an alias for the <command>halt</command>
124 command.</para>
125
126 <para>There are a number of directories under <filename
127 class="directory">/etc/rc.d</filename> that look like <filename
128 class="directory">rc?.d</filename> (where ? is the number of the run-level) and
129 <filename class="directory">rcsysinit.d</filename>, all containing a number of
130 symbolic links. Some begin with a <emphasis>K</emphasis>, the others begin with
131 an <emphasis>S</emphasis>, and all of them have two numbers following the
132 initial letter. The K means to stop (kill) a service and the S means to start a
133 service. The numbers determine the order in which the scripts are run, from 00
134 to 99&mdash;the lower the number the earlier it gets executed. When
135 <command>init</command> switches to another run-level, the appropriate services
136 are either started or stopped, depending on the runlevel chosen.</para>
137
138 <para>The real scripts are in <filename
139 class="directory">/etc/rc.d/init.d</filename>. They do the actual work, and
140 the symlinks all point to them. K links and S links point to
141 the same script in <filename class="directory">/etc/rc.d/init.d</filename>.
142 This is because the scripts can be called with different parameters like
143 <parameter>start</parameter>, <parameter>stop</parameter>,
144 <parameter>restart</parameter>, <parameter>reload</parameter>, and
145 <parameter>status</parameter>. When a K link is encountered, the appropriate
146 script is run with the <parameter>stop</parameter> argument. When an S link
147 is encountered, the appropriate script is run with the
148 <parameter>start</parameter> argument.</para>
149
150 <para>There is one exception to this explanation. Links that start
151 with an <emphasis>S</emphasis> in the <filename
152 class="directory">rc0.d</filename> and <filename
153 class="directory">rc6.d</filename> directories will not cause anything
154 to be started. They will be called with the parameter
155 <parameter>stop</parameter> to stop something. The logic behind this
156 is that when a user is going to reboot or halt the system, nothing
157 needs to be started. The system only needs to be stopped.</para>
158
159 <para>These are descriptions of what the arguments make the scripts
160 do:</para>
161
162 <variablelist>
163
164 <varlistentry>
165 <term><parameter>start</parameter></term>
166 <listitem>
167 <para>The service is started.</para>
168 </listitem>
169 </varlistentry>
170
171 <varlistentry>
172 <term><parameter>stop</parameter></term>
173 <listitem>
174 <para>The service is stopped.</para>
175 </listitem>
176 </varlistentry>
177
178 <varlistentry>
179 <term><parameter>restart</parameter></term>
180 <listitem>
181 <para>The service is stopped and then started again.</para>
182 </listitem>
183 </varlistentry>
184
185 <varlistentry>
186 <term><parameter>reload</parameter></term>
187 <listitem>
188 <para>The configuration of the service is updated.
189 This is used after the configuration file of a service was modified, when
190 the service does not need to be restarted.</para>
191 </listitem>
192 </varlistentry>
193
194 <varlistentry>
195 <term><parameter>status</parameter></term>
196 <listitem>
197 <para>Tells if the service is running and with which PIDs.</para>
198 </listitem>
199 </varlistentry>
200
201 </variablelist>
202
203 <para>Feel free to modify the way the boot process works (after all,
204 it is your own LFS system). The files given here are an example of how
205 it can be done.</para>
206
207 </sect3>
208 </sect2>
209
210 <sect2 id="ch-scripts-clock">
211 <title>Configuring the System Clock</title>
212
213 <sect3 id="ch-scripts-setclock">
214 <title>System V Clock Configuration</title>
215
216 <indexterm zone="ch-scripts-setclock">
217 <primary sortas="d-setclock">setclock</primary>
218 <secondary>configuring</secondary></indexterm>
219
220 <para>The <command>setclock</command> script reads the time from the hardware
221 clock, also known as the BIOS or the Complementary Metal Oxide Semiconductor
222 (CMOS) clock. If the hardware clock is set to UTC, this script will convert the
223 hardware clock's time to the local time using the
224 <filename>/etc/localtime</filename> file (which tells the
225 <command>hwclock</command> program which timezone the user is in). There is no
226 way to detect whether or not the hardware clock is set to UTC, so this
227 needs to be configured manually.</para>
228
229 <para>The <command>setclock</command> is run via
230 <application>udev</application> when the kernel detects the hardware
231 capability upon boot. It can also be run manually with the stop parameter to
232 store the system time to the CMOS clock.</para>
233
234 <para>If you cannot remember whether or not the hardware clock is set to UTC,
235 find out by running the <userinput>hwclock --localtime --show</userinput>
236 command. This will display what the current time is according to the hardware
237 clock. If this time matches whatever your watch says, then the hardware clock is
238 set to local time. If the output from <command>hwclock</command> is not local
239 time, chances are it is set to UTC time. Verify this by adding or subtracting
240 the proper amount of hours for the timezone to the time shown by
241 <command>hwclock</command>. For example, if you are currently in the MST
242 timezone, which is also known as GMT -0700, add seven hours to the local
243 time.</para>
244
245 <para>Change the value of the <envar>UTC</envar> variable below
246 to a value of <parameter>0</parameter> (zero) if the hardware clock
247 is <emphasis>not</emphasis> set to UTC time.</para>
248
249 <para>Create a new file <filename>/etc/sysconfig/clock</filename> by running
250 the following:</para>
251
252<screen><userinput>cat &gt; /etc/sysconfig/clock &lt;&lt; "EOF"
253<literal># Begin /etc/sysconfig/clock
254
255UTC=1
256
257# Set this to any options you might need to give to hwclock,
258# such as machine hardware clock type for Alphas.
259CLOCKPARAMS=
260
261# End /etc/sysconfig/clock</literal>
262EOF</userinput></screen>
263
264 <para>A good hint explaining how to deal with time on LFS is available
265 at <ulink url="&hints-root;time.txt"/>. It explains issues such as
266 time zones, UTC, and the <envar>TZ</envar> environment variable.</para>
267
268 <note><para>The CLOCKPARAMS and UTC paramaters may be alternatively set
269 in the <filename>/etc/sysconfig/rc.site</filename> file.</para></note>
270
271 </sect3>
272 </sect2>
273
274 <sect2 id="ch-scripts-console">
275 <?dbhtml filename="console.html"?>
276
277 <title>Configuring the Linux Console</title>
278
279 <indexterm zone="ch-scripts-console">
280 <primary sortas="d-console">console</primary>
281 <secondary>configuring</secondary>
282 </indexterm>
283
284 <para>This section discusses how to configure the <command>console</command>
285 bootscript that sets up the keyboard map, console font and console kernel log
286 level. If non-ASCII characters (e.g., the copyright sign, the British pound
287 sign and Euro symbol) will not be used and the keyboard is a U.S. one, much
288 of this section can be skipped. Without the configuration file, (or
289 equivalent settings in <filename>rc.site</filename>), the
290 <command>console</command> bootscript will do nothing.</para>
291
292 <para>The <command>console</command> script reads the
293 <filename>/etc/sysconfig/console</filename> file for configuration
294 information. Decide which keymap and screen font will be used. Various
295 language-specific HOWTOs can also help with this, see <ulink
296 url="http://www.tldp.org/HOWTO/HOWTO-INDEX/other-lang.html"/>. If still in
297 doubt, look in the <filename class="directory">/usr/share/keymaps</filename>
298 and <filename class="directory">/usr/share/consolefonts</filename> directories
299 for valid keymaps and screen fonts. Read <filename>loadkeys(1)</filename> and
300 <filename>setfont(8)</filename> manual pages to determine the correct
301 arguments for these programs.</para>
302
303 <para>The <filename>/etc/sysconfig/console</filename> file should contain lines
304 of the form: VARIABLE="value". The following variables are recognized:</para>
305 <variablelist>
306
307 <varlistentry>
308 <term>LOGLEVEL</term>
309 <listitem>
310 <para>This variable specifies the log level for kernel messages sent
311 to the console as set by <command>dmesg</command>. Valid levels are
312 from "1" (no messages) to "8". The default level is "7".</para>
313 </listitem>
314 </varlistentry>
315
316 <varlistentry>
317 <term>KEYMAP</term>
318 <listitem>
319 <para>This variable specifies the arguments for the
320 <command>loadkeys</command> program, typically, the name of keymap
321 to load, e.g., <quote>es</quote>. If this variable is not set, the
322 bootscript will not run the <command>loadkeys</command> program,
323 and the default kernel keymap will be used.</para>
324 </listitem>
325 </varlistentry>
326
327 <varlistentry>
328 <term>KEYMAP_CORRECTIONS</term>
329 <listitem>
330 <para>This (rarely used) variable
331 specifies the arguments for the second call to the
332 <command>loadkeys</command> program. This is useful if the stock keymap
333 is not completely satisfactory and a small adjustment has to be made. E.g.,
334 to include the Euro sign into a keymap that normally doesn't have it,
335 set this variable to <quote>euro2</quote>.</para>
336 </listitem>
337 </varlistentry>
338
339 <varlistentry>
340 <term>FONT</term>
341 <listitem>
342 <para>This variable specifies the arguments for the
343 <command>setfont</command> program. Typically, this includes the font
344 name, <quote>-m</quote>, and the name of the application character
345 map to load. E.g., in order to load the <quote>lat1-16</quote> font
346 together with the <quote>8859-1</quote> application character map
347 (as it is appropriate in the USA),
348 <!-- because of the copyright sign -->
349 set this variable to <quote>lat1-16 -m 8859-1</quote>.
350 In UTF-8 mode, the kernel uses the application character map for
351 conversion of composed 8-bit key codes in the keymap to UTF-8, and thus
352 the argument of the "-m" parameter should be set to the encoding of the
353 composed key codes in the keymap.</para>
354
355 </listitem>
356 </varlistentry>
357
358 <varlistentry>
359 <term>UNICODE</term>
360 <listitem>
361 <para>Set this variable to <quote>1</quote>, <quote>yes</quote> or
362 <quote>true</quote> in order to put the
363 console into UTF-8 mode. This is useful in UTF-8 based locales and
364 harmful otherwise.</para>
365 </listitem>
366 </varlistentry>
367
368 <varlistentry>
369 <term>LEGACY_CHARSET</term>
370 <listitem>
371 <para>For many keyboard layouts, there is no stock Unicode keymap in
372 the Kbd package. The <command>console</command> bootscript will
373 convert an available keymap to UTF-8 on the fly if this variable is
374 set to the encoding of the available non-UTF-8 keymap.</para>
375 </listitem>
376 </varlistentry>
377
378 </variablelist>
379
380 <para>Some examples:</para>
381
382 <itemizedlist>
383
384 <listitem>
385 <para>For a non-Unicode setup, only the KEYMAP and FONT variables are
386 generally needed. E.g., for a Polish setup, one would use:</para>
387<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
388<literal># Begin /etc/sysconfig/console
389
390KEYMAP="pl2"
391FONT="lat2a-16 -m 8859-2"
392
393# End /etc/sysconfig/console</literal>
394EOF</userinput></screen>
395 </listitem>
396
397 <listitem>
398 <para>As mentioned above, it is sometimes necessary to adjust a
399 stock keymap slightly. The following example adds the Euro symbol to the
400 German keymap:</para>
401
402<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
403<literal># Begin /etc/sysconfig/console
404
405KEYMAP="de-latin1"
406KEYMAP_CORRECTIONS="euro2"
407FONT="lat0-16 -m 8859-15"
408
409# End /etc/sysconfig/console</literal>
410EOF</userinput></screen>
411 </listitem>
412
413 <listitem>
414 <para>The following is a Unicode-enabled example for Bulgarian, where a
415 stock UTF-8 keymap exists:</para>
416
417<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
418<literal># Begin /etc/sysconfig/console
419
420UNICODE="1"
421KEYMAP="bg_bds-utf8"
422FONT="LatArCyrHeb-16"
423
424# End /etc/sysconfig/console</literal>
425EOF</userinput></screen>
426 </listitem>
427
428 <listitem>
429 <para>Due to the use of a 512-glyph LatArCyrHeb-16 font in the previous
430 example, bright colors are no longer available on the Linux console unless
431 a framebuffer is used. If one wants to have bright colors without
432 framebuffer and can live without characters not belonging to his language,
433 it is still possible to use a language-specific 256-glyph font, as
434 illustrated below:</para>
435
436<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
437<literal># Begin /etc/sysconfig/console
438
439UNICODE="1"
440KEYMAP="bg_bds-utf8"
441FONT="cyr-sun16"
442
443# End /etc/sysconfig/console</literal>
444EOF</userinput></screen>
445 </listitem>
446
447 <listitem>
448 <para>The following example illustrates keymap autoconversion from
449 ISO-8859-15 to UTF-8 and enabling dead keys in Unicode mode:</para>
450
451<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
452<literal># Begin /etc/sysconfig/console
453
454UNICODE="1"
455KEYMAP="de-latin1"
456KEYMAP_CORRECTIONS="euro2"
457LEGACY_CHARSET="iso-8859-15"
458FONT="LatArCyrHeb-16 -m 8859-15"
459
460# End /etc/sysconfig/console</literal>
461EOF</userinput></screen>
462 </listitem>
463
464 <listitem>
465 <para>Some keymaps have dead keys (i.e., keys that don't produce a
466 character by themselves, but put an accent on the character produced
467 by the next key) or define composition rules (such as: <quote>press
468 Ctrl+. A E to get &AElig;</quote> in the default keymap).
469 Linux-&linux-version; interprets dead keys and composition rules in the
470 keymap correctly only when the source characters to be composed together
471 are not multibyte. This deficiency doesn't affect keymaps for European
472 languages, because there accents are added to unaccented ASCII
473 characters, or two ASCII characters are composed together. However, in
474 UTF-8 mode it is a problem, e.g., for the Greek language, where one
475 sometimes needs to put an accent on the letter <quote>alpha</quote>.
476 The solution is either to avoid the use of UTF-8, or to install the
477 X window system that doesn't have this limitation in its input
478 handling.</para>
479 </listitem>
480
481 <listitem>
482 <para>For Chinese, Japanese, Korean and some other languages, the Linux
483 console cannot be configured to display the needed characters. Users
484 who need such languages should install the X Window System, fonts that
485 cover the necessary character ranges, and the proper input method (e.g.,
486 SCIM, it supports a wide variety of languages).</para>
487 </listitem>
488
489 </itemizedlist>
490
491 <!-- Added because folks keep posting their console file with X questions
492 to blfs-support list -->
493 <note>
494 <para>The <filename>/etc/sysconfig/console</filename> file only controls
495 the Linux text console localization. It has nothing to do with setting
496 the proper keyboard layout and terminal fonts in the X Window System, with
497 ssh sessions or with a serial console. In such situations, limitations
498 mentioned in the last two list items above do not apply.</para>
499 </note>
500
501 </sect2>
502
503 <sect2 id="ch-scripts-createfiles">
504 <title>Creating Files at Boot</title>
505
506 <indexterm zone="ch-scripts-createfiles">
507 <primary sortas="d-createfiles">File creation at boot</primary>
508 <secondary>configuring</secondary>
509 </indexterm>
510
511 <para>At times, it is desired to create files at boot time. For instance,
512 the <filename class="directory">/tmp/.ICE-unix</filename> directory
513 may be desired. This can be done by creating an entry in the
514 <filename>/etc/sysconfig/createfiles</filename> configuration script.
515 The format of this file is embedded in the comments of the default
516 configuration file.</para>
517 </sect2>
518
519 <sect2 id="ch-scripts-sysklogd">
520 <title>Configuring the sysklogd Script</title>
521
522 <indexterm zone="ch-scripts-sysklogd">
523 <primary sortas="d-sysklogd">sysklogd</primary>
524 <secondary>configuring</secondary>
525 </indexterm>
526
527 <para>The <filename>sysklogd</filename> script invokes the
528 <command>syslogd</command> program as a part of System V initialization. The
529 <parameter>-m 0</parameter> option turns off the periodic timestamp mark that
530 <command>syslogd</command> writes to the log files every 20 minutes by
531 default. If you want to turn on this periodic timestamp mark, edit
532 <filename>/etc/sysconfig/rc.site</filename> and define the variable
533 SYSKLOGD_PARMS to the desired value. For instance, to remove all parameters,
534 set the variable to a null value:</para>
535
536<screen role="nodump">SYSKLOGD_PARMS=</screen>
537
538 <para>See <userinput>man syslogd</userinput> for more options.</para>
539
540 </sect2>
541
542 <sect2 id="ch-scripts-site">
543 <title>The rc.site File</title>
544
545 <indexterm zone="ch-scripts-site">
546 <primary sortas="a-rc.site">rc.site</primary>
547 </indexterm>
548
549 <para>The optional <filename>/etc/sysconfig/rc.site</filename> file contains
550 settings that are automatically set for each SystemV boot script. It can
551 alternatively set the values specified in the <filename>hostname</filename>,
552 <filename>console</filename>, and <filename>clock</filename> files in the
553 <filename class='directory'>/etc/sysconfig/</filename> directory. If the
554 associated variables are present in both these separate files and
555 <filename>rc.site</filename>, the values in the script specific files have
556 precedence. </para>
557
558 <para><filename>rc.site</filename> also contains parameters that can
559 customize other aspects of the boot process. Setting the IPROMPT variable
560 will enable selective running of bootscripts. Other options are described
561 in the file comments. The default version of the file is as follows:</para>
562
563 <!-- Use role to fix a pdf generation problem -->
564 <screen role="auto">&site;</screen>
565
566 <sect3>
567 <title>Customizing the Boot and Shutdown Scripts</title>
568
569 <para>The LFS boot scripts boot and shut down a system in a fairly
570 efficient manner, but there are a few tweaks that you can make in the
571 rc.site file to improve speed even more and to adjust messages according
572 to your preferences. To do this, adjust the settings in
573 the <filename>/etc/sysconfig/rc.site</filename> file above.</para>
574
575 <itemizedlist>
576
577 <listitem><para>During the boot script <filename>udev</filename>, there is
578 a call to <command>udev settle</command> that requires some time to
579 complete. This time may or may not be required depending on devices present
580 in the system. If you only have simple partitions and a single ethernet
581 card, the boot process will probably not need to wait for this command. To
582 skip it, set the variable OMIT_UDEV_SETTLE=y.</para></listitem>
583
584 <listitem><para>The boot script <filename>udev_retry</filename> also runs
585 <command>udev settle</command> by default. This command is only needed by
586 default if the <filename class='directory'>/var</filename> directory is
587 separately mounted. This is because the clock needs the file
588 <filename>/var/lib/hwclock/adjtime</filename>. Other customizations may
589 also need to wait for udev to complete, but in many installations it is not
590 needed. Skip the command by setting the variable OMIT_UDEV_RETRY_SETTLE=y.
591 </para></listitem>
592
593 <listitem><para>By default, the file system checks are silent. This can
594 appear to be a delay during the bootup process. To turn on the
595 <command>fsck</command> output, set the variable VERBOSE_FSCK=y.
596 </para></listitem>
597
598 <listitem><para>When rebooting, you may want to skip the filesystem check,
599 <command>fsck</command>, completely. To do this, either create the file
600 <filename>/fastboot</filename> or reboot the system with the command
601 <command>/sbin/shutdown -f -r now</command>. On the other hand, you can
602 force all file systems to be checked by creating
603 <filename>/forcefsck</filename> or running <command>shutdown</command> with
604 the <parameter>-F</parameter> parameter instead of <parameter>-f</parameter>.
605 </para>
606
607 <para>Setting the variable FASTBOOT=y will disable <command>fsck</command>
608 during the boot process until it is removed. This is not recommended
609 on a permanent basis.</para></listitem>
610
611 <listitem><para>Normally, all files in the <filename
612 class='directory'>/tmp</filename> directory are deleted at boot time.
613 Depending on the number of files or directories present, this can cause a
614 noticeable delay in the boot process. To skip removing these files set the
615 variable SKIPTMPCLEAN=y.</para></listitem>
616
617 <listitem><para>During shutdown, the <command>init</command> program sends
618 a TERM signal to each program it has started (e.g. agetty), waits for a set
619 time (default 3 seconds), and sends each process a KILL signal and waits
620 again. This process is repeated in the <command>sendsignals</command>
621 script for any processes that are not shut down by their own scripts. The
622 delay for <command>init</command> can be set by passing a parameter. For
623 example to remove the delay in <command>init</command>, pass the -t0
624 parameter when shutting down or rebooting (e.g. <command>/sbin/shutdown
625 -t0 -r now</command>). The delay for the <command>sendsignals</command>
626 script can be skipped by setting the parameter
627 KILLDELAY=0.</para></listitem>
628
629 </itemizedlist>
630
631 </sect3>
632 </sect2>
633</sect1>
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