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1 swift 1.10 <?xml version='1.0' encoding='UTF-8'?>
2     <!DOCTYPE sections SYSTEM "/dtd/book.dtd">
3    
4 swift 1.1 <!-- The content of this document is licensed under the CC-BY-SA license -->
5     <!-- See http://creativecommons.org/licenses/by-sa/1.0 -->
6    
7 swift 1.14 <!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/handbook/hb-working-rcscripts.xml,v 1.13 2004/05/06 22:45:58 neysx Exp $ -->
8 swift 1.1
9     <sections>
10     <section>
11     <title>Runlevels</title>
12     <subsection>
13 swift 1.4 <title>Booting your System</title>
14     <body>
15    
16     <p>
17     When you boot your system, you will notice lots of text floating by. If you pay
18     close attention, you will notice this text is the same every time you reboot
19     your system. The sequence of all these actions is called the <e>boot
20     sequence</e> and is (more or less) statically defined.
21     </p>
22    
23     <p>
24     First, your boot loader will load the kernel image you have defined in the
25     boot loader configuration into memory after which it tells the CPU to run the
26 swift 1.6 kernel. When the kernel is loaded and run, it initializes all kernel-specific
27 swift 1.4 structures and tasks and starts the <c>init</c> process.
28     </p>
29    
30     <p>
31     This process then makes sure that all filesystems (defined in
32     <path>/etc/fstab</path>) are mounted and ready to be used. Then it executes
33     several scripts located in <path>/etc/init.d</path>, which will start the
34 swift 1.8 services you need in order to have a successfully booted system.
35 swift 1.4 </p>
36    
37     <p>
38     Finally, when all scripts are executed, <c>init</c> activates the terminals
39 swift 1.14 (in most cases just the virtual consoles which are hidden beneath <c>Alt-F1</c>,
40 swift 1.4 <c>Alt-F2</c>, etc.) attaching a special process called <c>agetty</c> to it.
41     This process will then make sure you are able to log on through these terminals
42     by running <c>login</c>.
43     </p>
44    
45     </body>
46     </subsection>
47     <subsection>
48     <title>Init Scripts</title>
49 swift 1.1 <body>
50    
51 swift 1.2 <p>
52 swift 1.4 Now <c>init</c> doesn't just execute the scripts in <path>/etc/init.d</path>
53     randomly. Even more, it doesn't run all scripts in <path>/etc/init.d</path>,
54 swift 1.7 only the scripts it is told to execute. It decides which scripts to execute by
55 swift 1.4 looking into <path>/etc/runlevels</path>.
56     </p>
57    
58     <p>
59     First, <c>init</c> runs all scripts from <path>/etc/init.d</path> that have
60     symbolic links inside <path>/etc/runlevels/boot</path>. Usually, it will
61     start the scripts in alphabetical order, but some scripts have dependency
62     information in them, telling the system that another script must be run before
63     they can be started.
64     </p>
65    
66     <p>
67     When all <path>/etc/runlevels/boot</path> referenced scripts are executed,
68     <c>init</c> continues with running the scripts that have a symbolic link to them
69     in <path>/etc/runlevels/default</path>. Again, it will use the alphabetical
70     order to decide what script to run first, unless a script has dependency
71 swift 1.7 information in it, in which case the order is changed to provide a valid
72     start-up sequence.
73 swift 1.2 </p>
74    
75     </body>
76     </subsection>
77     <subsection>
78 swift 1.4 <title>How Init Works</title>
79 swift 1.2 <body>
80    
81     <p>
82 swift 1.4 Of course <c>init</c> doesn't decide all that by itself. It needs a
83     configuration file that specifies what actions need to be taken. This
84     configuration file is <path>/etc/inittab</path>.
85 swift 1.2 </p>
86    
87 swift 1.4 <p>
88     If you remember the boot sequence we have just explained to you, you will
89     remember that <c>init</c>'s first action is to mount all filesystems. This is
90     defined in the following line from <path>/etc/inittab</path>:
91     </p>
92    
93     <pre caption="The system initialisation line in /etc/inittab">
94 swift 1.2 si::sysinit:/sbin/rc sysinit
95     </pre>
96    
97     <p>
98 swift 1.4 This line tells <c>init</c> that it must run <c>/sbin/rc sysinit</c> to
99 swift 1.6 initialize the system. The <path>/sbin/rc</path> script takes care of the
100 swift 1.4 initialisation, so you might say that <c>init</c> doesn't do much -- it
101     delegates the task of initialising the system to another process.
102 swift 1.2 </p>
103    
104     <p>
105 swift 1.4 Second, <c>init</c> executed all scripts that had symbolic links in
106     <path>/etc/runlevels/boot</path>. This is defined in the following line:
107 swift 1.2 </p>
108    
109 swift 1.4 <pre caption="The system initialisation, continued">
110     rc::bootwait:/sbin/rc boot
111 swift 1.2 </pre>
112    
113     <p>
114 swift 1.4 Again the <c>rc</c> script performs the necessary tasks. Note that the option
115     given to <c>rc</c> (<e>boot</e>) is the same as the subdirectory of
116     <path>/etc/runlevels</path> that is used.
117 swift 1.2 </p>
118    
119     <p>
120 swift 1.4 Now <c>init</c> checks its configuration file to see what <e>runlevel</e> it
121     should run. To decide this, it reads the following line from
122     <path>/etc/inittab</path>:
123 swift 1.2 </p>
124    
125 swift 1.4 <pre caption="The initdefault line">
126     id:3:initdefault:
127     </pre>
128 swift 1.2
129     <p>
130 swift 1.4 In this case (which the majority of Gentoo users will use), the <e>runlevel</e>
131     id is 3. Using this information, <c>init</c> checks what it must run to start
132     <e>runlevel 3</e>:
133 swift 1.2 </p>
134    
135 swift 1.4 <pre caption="The runlevel definitions">
136 swift 1.2 l0:0:wait:/sbin/rc shutdown
137     l1:S1:wait:/sbin/rc single
138     l2:2:wait:/sbin/rc nonetwork
139     l3:3:wait:/sbin/rc default
140     l4:4:wait:/sbin/rc default
141     l5:5:wait:/sbin/rc default
142     l6:6:wait:/sbin/rc reboot
143     </pre>
144    
145     <p>
146 swift 1.4 The line that defines level 3, again, uses the <c>rc</c> script to start the
147     services (now with argument <e>default</e>). Again note that the argument of
148     <c>rc</c> is the same as the subdirectory from <path>/etc/runlevels</path>.
149 swift 1.2 </p>
150    
151     <p>
152 swift 1.4 When <c>rc</c> has finished, <c>init</c> decides what virtual consoles it should
153     activate and what commands need to be run at each console:
154 swift 1.2 </p>
155    
156 swift 1.4 <pre caption="The virtual consoles definition">
157     c1:12345:respawn:/sbin/agetty 38400 tty1 linux
158     c2:12345:respawn:/sbin/agetty 38400 tty2 linux
159     c3:12345:respawn:/sbin/agetty 38400 tty3 linux
160     c4:12345:respawn:/sbin/agetty 38400 tty4 linux
161     c5:12345:respawn:/sbin/agetty 38400 tty5 linux
162     c6:12345:respawn:/sbin/agetty 38400 tty6 linux
163     </pre>
164    
165 swift 1.1
166     </body>
167     </subsection>
168     <subsection>
169 swift 1.4 <title>What is a runlevel?</title>
170 swift 1.1 <body>
171    
172 swift 1.2 <p>
173 swift 1.4 You have seen that <c>init</c> uses a numbering scheme to decide what
174     <e>runlevel</e> it should activate. A <e>runlevel</e> is a state in which
175     your system is running and contains a collection of scripts (runlevel scripts or
176     <e>initscripts</e>) that must be executed when you enter or leave a runlevel.
177     </p>
178    
179     <p>
180     In Gentoo, there are seven runlevels defined: three internal runlevels, and four
181     user-defined runlevels. The internal runlevels are called <e>sysinit</e>,
182     <e>shutdown</e> and <e>reboot</e> and do exactly what their names imply:
183 swift 1.6 initialize the system, powering off the system and rebooting the system.
184 swift 1.4 </p>
185    
186     <p>
187     The user-defined runlevels are those with an accompanying
188     <path>/etc/runlevels</path> subdirectory: <path>boot</path>,
189     <path>default</path>, <path>nonetwork</path> and <path>single</path>. The
190     <path>boot</path> runlevel starts all system-necessary services which all other
191     runlevels use. The remaining three runlevels differ in what services they start:
192     <path>default</path> is used for day-to-day operations, <path>nonetwork</path>
193     is used in case no network connectivity is required, and <path>single</path> is
194     used when you need to fix the system.
195 swift 1.2 </p>
196    
197 swift 1.4 </body>
198     </subsection>
199     <subsection>
200     <title>Working with the Init Scripts</title>
201     <body>
202    
203 swift 1.2 <p>
204 swift 1.4 The scripts that the <c>rc</c> process starts are called <e>init scripts</e>.
205 swift 1.2 Each script in <path>/etc/init.d</path> can be executed with the arguments
206     <e>start</e>, <e>stop</e>, <e>restart</e>, <e>pause</e>, <e>zap</e>,
207     <e>status</e>, <e>ineed</e>, <e>iuse</e>, <e>needsme</e>, <e>usesme</e> or
208     <e>broken</e>.
209     </p>
210    
211     <p>
212     To start, stop or restart a service (and all depending services), <c>start</c>,
213     <c>stop</c> and <c>restart</c> should be used:
214     </p>
215    
216     <pre caption="Starting Postfix">
217     # <i>/etc/init.d/postfix start</i>
218     </pre>
219 swift 1.4
220     <note>
221     Only the services that <e>need</e> the given service are stopped or restarted.
222     The other depending services (those that <e>use</e> the service but don't need
223     it) are left untouched.
224     </note>
225 swift 1.2
226     <p>
227     If you want to stop a service, but not the services that depend on it, you can
228     use the <c>pause</c> argument:
229     </p>
230    
231     <pre caption="Stopping Postfix but keep the depending services running">
232     # <i>/etc/init.d/postfix pause</i>
233     </pre>
234    
235     <p>
236     If you want to see what status a service has (started, stopped, paused, ...) you
237     can use the <c>status</c> argument:
238     </p>
239    
240     <pre caption="Status information for postfix">
241     # <i>/etc/init.d/postfix status</i>
242     </pre>
243    
244     <p>
245 swift 1.3 If the status information tells you that the service is running, but you know
246     that it is not, then you can reset the status information to "stopped" with the
247     <c>zap</c> argument:
248 swift 1.2 </p>
249    
250     <pre caption="Resetting status information for postfix">
251     # <i>/etc/init.d/postfix zap</i>
252     </pre>
253    
254     <p>
255     To also ask what dependencies the service has, you can use <c>iuse</c> or
256     <c>ineed</c>. With <c>ineed</c> you can see the services that are really
257     necessary for the correct functioning of the service. <c>iuse</c> on the other
258     hand shows the services that can be used by the service, but are not necessary
259     for the correct functioning.
260     </p>
261    
262     <pre caption="Requesting a list of all necessary services on which Postfix depends">
263     # <i>/etc/init.d/postfix ineed</i>
264     </pre>
265    
266     <p>
267     Similarly, you can ask what services require the service (<c>needsme</c>) or can
268     use it (<c>usesme</c>):
269     </p>
270    
271     <pre caption="Requesting a list of all services that require Postfix">
272     # <i>/etc/init.d/postfix needsme</i>
273     </pre>
274    
275     <p>
276     Finally, you can ask what dependencies the service requires but that are
277     missing:
278     </p>
279    
280     <pre caption="Requesting a list of missing dependencies for Postfix">
281     # <i>/etc/init.d/postfix broken</i>
282     </pre>
283 swift 1.1
284     </body>
285     </subsection>
286     </section>
287     <section>
288     <title>Working with rc-update</title>
289     <subsection>
290     <title>What is rc-update?</title>
291     <body>
292    
293 swift 1.2 <p>
294     Gentoo's init system uses a dependency-tree to decide what service needs to be
295     started first. As this is a tedious task that we wouldn't want our users to do
296     manually, we have created tools that ease the administration of the runlevels
297     and init scripts.
298     </p>
299    
300     <p>
301     With <c>rc-update</c> you can add and remove init scripts to a runlevel. The
302     <c>rc-update</c> tool will then automatically ask the <c>depscan.sh</c> script
303     to rebuild the dependency tree.
304     </p>
305    
306 swift 1.1 </body>
307     </subsection>
308     <subsection>
309     <title>Adding and Removing Services</title>
310     <body>
311    
312 swift 1.2 <p>
313     You have already added init scripts to the "default" runlevel during the
314 swift 1.7 installation of Gentoo. At that time you might not have had a clue what the
315 swift 1.2 "default" is for, but now you should. The <c>rc-update</c> script requires a
316     second argument that defines the action: <e>add</e>, <e>del</e> or <e>show</e>.
317     </p>
318    
319     <p>
320     To add or remove an init script, just give <c>rc-update</c> the <c>add</c> or
321     <c>del</c> argument, followed by the init script and the runlevel. For instance:
322     </p>
323    
324     <pre caption="Removing Postfix from the default runlevel">
325     # <i>rc-update del postfix default</i>
326     </pre>
327    
328     <p>
329     The <c>rc-update show</c> command will show all the available init scripts and
330     list at which runlevels they will execute:
331     </p>
332    
333     <pre caption="Receiving init script information">
334     # <i>rc-update show</i>
335     </pre>
336 swift 1.1
337     </body>
338     </subsection>
339     </section>
340     <section>
341     <title>Configuring Services</title>
342     <subsection>
343 swift 1.2 <title>Why the Need for Extra Configuration?</title>
344 swift 1.1 <body>
345    
346 swift 1.2 <p>
347 swift 1.5 Init scripts can be quite complex. It is therefore not really interesting to
348     have the users directly edit the init script, as it would make it more
349     error-prone. It is however important to be able to configure such a service. For
350     instance, you might want to give more options to the service itself.
351 swift 1.2 </p>
352    
353     <p>
354     A second reason to have this configuration outside the init script is to be able
355     to update the init scripts without being afraid that your configuration changes
356     are undone.
357     </p>
358    
359 swift 1.1 </body>
360     </subsection>
361     <subsection>
362     <title>The /etc/conf.d Directory</title>
363     <body>
364    
365 swift 1.2 <p>
366     Gentoo provides an easy way to configure such a service: every init script that
367     can be configured has a file in <path>/etc/conf.d</path>. For instance, the
368     apache2 initscript (called <path>/etc/init.d/apache2</path>) has a
369     configuration file called <path>/etc/conf.d/apache2</path>, which can contain
370     the options you want to give to the Apache 2 server when it is started:
371     </p>
372    
373     <pre caption="Variable defined in /etc/conf.d/apache2">
374     APACHE2_OPTS="-D PHP4"
375     </pre>
376    
377     <p>
378     Such a configuration file contains variables and variables alone (just like
379     <path>/etc/make.conf</path>), making it very easy to configure services. It also
380     allows us to provide more information about the variables (as comments).
381     </p>
382    
383 swift 1.1 </body>
384     </subsection>
385     </section>
386     <section>
387 swift 1.2 <title>Writing Init Scripts</title>
388 swift 1.1 <subsection>
389     <title>Do I Have To?</title>
390     <body>
391    
392 swift 1.2 <p>
393     No. Writing an init script is usually not necessary as Gentoo provides
394     ready-to-use init scripts for all provided services. However, you might have
395     installed a service without using Portage, in which case you will most likely
396     have to create an init script.
397     </p>
398    
399     <p>
400     Do not use the init script provided by the service if it isn't explicitly
401     written for Gentoo: Gentoo's init scripts are not compatible with the init
402     scripts used by other distributions!
403     </p>
404    
405 swift 1.1 </body>
406     </subsection>
407     <subsection>
408     <title>Layout</title>
409     <body>
410    
411 swift 1.2 <p>
412     The basic layout of an init script is shown below.
413     </p>
414    
415     <pre caption="Basic layout of an init script">
416     #!/sbin/runscript
417    
418     depend() {
419     <comment>(Dependency information)</comment>
420     }
421    
422     start() {
423     <comment>(Commands necessary to start the service)</comment>
424     }
425    
426     stop() {
427     <comment>(Commands necessary to stop the service)</comment>
428     }
429    
430     restart() {
431     <comment>(Commands necessary to restart the service)</comment>
432     }
433     </pre>
434    
435     <p>
436     Any init script <e>requires</e> the <c>start()</c> function to be defined. All
437     other sections are optional.
438     </p>
439    
440 swift 1.1 </body>
441     </subsection>
442     <subsection>
443     <title>Dependencies</title>
444     <body>
445    
446 swift 1.2 <p>
447     There are two dependencies you can define: <c>use</c> and <c>need</c>. As we
448     have mentioned before, the <c>need</c> dependency is more strict than the
449     <c>use</c> dependency. Following this dependency type you enter the service
450     you depend on, or the <e>virtual</e> dependency.
451     </p>
452    
453     <p>
454     A <e>virtual</e> dependency is a dependency that a service provides, but that is
455     not provided solely by that service. Your init script can depend on a system
456     logger, but there are many system loggers available (metalogd, syslog-ng,
457     sysklogd, ...). As you cannot <c>need</c> every single one of them (no sensible
458     system has all these system loggers installed and running) we made sure that
459     all these services <c>provide</c> a virtual dependency.
460     </p>
461    
462     <p>
463     Let us take a look at the dependency information for the postfix service.
464     </p>
465    
466     <pre caption="Dependency information for Postfix">
467     depend() {
468     need net
469     use logger dns
470     provide mta
471     }
472     </pre>
473    
474     <p>
475     As you can see, the postfix service:
476     </p>
477    
478     <ul>
479     <li>
480     requires the (virtual) <c>net</c> dependency (which is provided by, for
481     instance, <path>/etc/init.d/net.eth0</path>)
482     </li>
483     <li>
484     uses the (virtual) <c>logger</c> dependency (which is provided by, for
485     instance, <path>/etc/init.d/syslog-ng</path>)
486     </li>
487     <li>
488     uses the (virtual) <c>dns</c> dependency (which is provided by, for
489     instance, <path>/etc/init.d/named</path>)
490     </li>
491     <li>
492     provides the (virtual) <c>mta</c> dependency (which is common for all mail
493     servers)
494     </li>
495     </ul>
496    
497 swift 1.1 </body>
498     </subsection>
499     <subsection>
500     <title>Controlling the Order</title>
501     <body>
502    
503 swift 1.2 <p>
504     In some cases you might not require a service, but want your service to be
505     started <c>before</c> (or <c>after</c>) another service <e>if</e> it is
506     available on the system (note the conditional - this is no dependency anymore)
507     <e>and</e> ran in the same runlevel (note the conditional - only services in the
508     same runlevel are involved). You can provide this information using the
509     <c>before</c> or <c>after</c> settings.
510     </p>
511    
512     <p>
513     As an example we view the settings of the Portmap service:
514     </p>
515    
516     <pre caption="The depend() function in the Portmap service">
517     depend() {
518     need net
519     before inetd
520     before xinetd
521     }
522     </pre>
523    
524     <p>
525     You can also use the "*" glob to catch all services in the same runlevel,
526     although this isn't adviseable.
527     </p>
528    
529     <pre caption="Running an init script as first script in the runlevel">
530     depend() {
531     before *
532     }
533     </pre>
534 swift 1.1
535     </body>
536     </subsection>
537     <subsection>
538     <title>Standard Functions</title>
539     <body>
540    
541 swift 1.2 <p>
542     Next to the <c>depend()</c> functionality, you also need to define the
543     <c>start()</c> function. This one contains all the commands necessary to
544 swift 1.6 initialize your service. It is adviseable to use the <c>ebegin</c> and
545 swift 1.2 <c>eend</c> functions to inform the user about what is happening:
546     </p>
547    
548     <pre caption="Example start() function">
549     start() {
550     ebegin "Starting my_service"
551     start-stop-daemon --start --quiet --exec /path/to/my_service
552     eend $?
553     }
554     </pre>
555    
556     <p>
557     If you need more examples of the <c>start()</c> function, please read the source
558     code of the available init scripts in your <path>/etc/init.d</path> directory.
559     As for <c>start-stop-daemon</c>, there is an excellent man page available if you
560     need more information:
561     </p>
562    
563     <pre caption="Getting the man page for start-stop-daemon">
564     # <i>man start-stop-daemon</i>
565     </pre>
566    
567     <p>
568     Other functions you can define are: <c>stop()</c> and <c>restart()</c>. You are
569     not obliged to define these functions! Our init system is intelligent enough to
570 swift 1.9 fill these functions by itself if you use <c>start-stop-daemon</c>.
571 swift 1.2 </p>
572    
573 swift 1.1 </body>
574     </subsection>
575     <subsection>
576     <title>Adding Custom Options</title>
577     <body>
578    
579 swift 1.2 <p>
580     If you want your init script to support more options than the ones we have
581     already encountered, you should add the option to the <c>opts</c> variable, and
582     create a function with the same name as the option. For instance, to support an
583     option called <c>restartdelay</c>:
584     </p>
585    
586     <pre caption="Supporting the restartdelay option">
587     opts="${opts} restartdelay"
588    
589     restartdelay() {
590     stop()
591     sleep 3 <comment># Wait 3 seconds before starting again</comment>
592     start()
593     }
594     </pre>
595    
596 swift 1.1 </body>
597     </subsection>
598     <subsection>
599     <title>Service Configuration Variables</title>
600     <body>
601 swift 1.2
602     <p>
603     You don't have to do anything to support a configuration file in
604     <path>/etc/conf.d</path>: if your init script is executed, the following files
605     are automatically sourced (i.e. the variables are available to use):
606     </p>
607    
608     <ul>
609     <li><path>/etc/conf.d/&lt;your init script&gt;</path></li>
610     <li><path>/etc/conf.d/basic</path></li>
611     <li><path>/etc/rc.conf</path></li>
612     </ul>
613    
614     <p>
615     Also, if your init script provides a virtual dependency (such as <c>net</c>),
616     the file associated with that dependency (such as <path>/etc/conf.d/net</path>)
617     will be sourced too.
618     </p>
619 swift 1.1
620     </body>
621     </subsection>
622     </section>
623 swift 1.12 <section>
624     <title>Changing the Runlevel Behaviour</title>
625     <subsection>
626     <title>Who might benefit from this?</title>
627     <body>
628    
629     <p>
630     Many laptop users know the situation: at home you need to start <c>net.eth0</c>
631     while you don't want to start <c>net.eth0</c> while you're on the road (as
632     there is no network available). With Gentoo you can alter the runlevel behaviour
633     to your own will.
634     </p>
635    
636     <p>
637     For instance you can create a second "default" runlevel which you can boot that
638     has other init scripts assigned to it. You can then select at boottime what
639     defalt runlevel you want to use.
640     </p>
641    
642     </body>
643     </subsection>
644     <subsection>
645     <title>Using SOFTLEVEL</title>
646     <body>
647    
648     <p>
649     First of all, create the runlevel directory for your second "default" runlevel.
650     As an example we create the <path>offline</path> runlevel:
651     </p>
652    
653     <pre caption="Creating a runlevel directory">
654     # <i>mkdir /etc/runlevels/offline</i>
655     </pre>
656    
657     <p>
658     Add the necessary init scripts to the newly created runlevels. For instance, if
659     you want to have an exact copy of your current <c>default</c> runlevel but
660     without <c>net.eth0</c>:
661     </p>
662    
663     <pre caption="Adding the necessary init scripts">
664     # <i>ls /etc/runlevels/default</i>
665 neysx 1.13 acpid domainname local net.eth0 netmount postfix syslog-ng vixie-cron
666 swift 1.12 # <i>rc-update add acpid offline</i>
667     # <i>rc-update add domainname offline</i>
668     # <i>rc-update add local offline</i>
669     # <i>rc-update add syslog-ng offline</i>
670     # <i>rc-update add vixie-cron offline</i>
671     </pre>
672    
673     <p>
674     Now edit your bootloader configuration and add a new entry for the
675     <c>offline</c> runlevel. For instance, in <path>/boot/grub/grub.conf</path>:
676     </p>
677    
678     <pre caption="Adding an entry for the offline runlevel">
679     title Gentoo Linux Offline Usage
680     root (hd0,0)
681     kernel (hd0,0)/kernel-2.4.25 root=/dev/hda3 <i>softlevel=offline</i>
682     </pre>
683    
684     <p>
685     Voila, you're all set now. If you boot your system and select the newly added
686     entry at boot, the <c>offline</c> runlevel will be used instead of the
687     <c>default</c> one.
688     </p>
689    
690     </body>
691     </subsection>
692     <subsection>
693     <title>Using BOOTLEVEL</title>
694     <body>
695    
696     <p>
697     Using <c>bootlevel</c> is completely analogous to <c>softlevel</c>. The only
698     difference here is that you define a second "boot" runlevel instead of a second
699     "default" runlevel.
700     </p>
701    
702     </body>
703     </subsection>
704     </section>
705 swift 1.1 </sections>

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