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1 | <?xml version='1.0'?> <!--*-nxml-*--> |
2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | |
e735f4d4 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
663996b3 MS |
4 | |
5 | <!-- | |
6 | This file is part of systemd. | |
7 | ||
8 | Copyright 2010 Lennart Poettering | |
9 | ||
10 | systemd is free software; you can redistribute it and/or modify it | |
11 | under the terms of the GNU Lesser General Public License as published by | |
12 | the Free Software Foundation; either version 2.1 of the License, or | |
13 | (at your option) any later version. | |
14 | ||
15 | systemd is distributed in the hope that it will be useful, but | |
16 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | Lesser General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU Lesser General Public License | |
21 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
22 | --> | |
23 | ||
60f067b4 | 24 | <refentry id="systemd" |
e735f4d4 MP |
25 | xmlns:xi="http://www.w3.org/2001/XInclude"> |
26 | ||
27 | <refentryinfo> | |
28 | <title>systemd</title> | |
29 | <productname>systemd</productname> | |
30 | ||
31 | <authorgroup> | |
32 | <author> | |
33 | <contrib>Developer</contrib> | |
34 | <firstname>Lennart</firstname> | |
35 | <surname>Poettering</surname> | |
36 | <email>lennart@poettering.net</email> | |
37 | </author> | |
38 | </authorgroup> | |
39 | </refentryinfo> | |
40 | ||
41 | <refmeta> | |
42 | <refentrytitle>systemd</refentrytitle> | |
43 | <manvolnum>1</manvolnum> | |
44 | </refmeta> | |
45 | ||
46 | <refnamediv> | |
47 | <refname>systemd</refname> | |
48 | <refname>init</refname> | |
49 | <refpurpose>systemd system and service manager</refpurpose> | |
50 | </refnamediv> | |
51 | ||
52 | <refsynopsisdiv> | |
53 | <cmdsynopsis> | |
54 | <command>systemd <arg choice="opt" rep="repeat">OPTIONS</arg></command> | |
55 | </cmdsynopsis> | |
56 | <cmdsynopsis> | |
57 | <command>init <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command> | |
58 | </cmdsynopsis> | |
59 | </refsynopsisdiv> | |
60 | ||
61 | <refsect1> | |
62 | <title>Description</title> | |
63 | ||
64 | <para>systemd is a system and service manager for Linux operating | |
65 | systems. When run as first process on boot (as PID 1), it acts as | |
66 | init system that brings up and maintains userspace | |
67 | services.</para> | |
68 | ||
69 | <para>For compatibility with SysV, if systemd is called as | |
70 | <command>init</command> and a PID that is not 1, it will execute | |
71 | <command>telinit</command> and pass all command line arguments | |
72 | unmodified. That means <command>init</command> and | |
73 | <command>telinit</command> are mostly equivalent when invoked from | |
74 | normal login sessions. See | |
75 | <citerefentry><refentrytitle>telinit</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
76 | for more information.</para> | |
77 | ||
78 | <para>When run as a system instance, systemd interprets the | |
79 | configuration file <filename>system.conf</filename> and the files | |
80 | in <filename>system.conf.d</filename> directories; when run as a | |
81 | user instance, systemd interprets the configuration file | |
82 | <filename>user.conf</filename> and the files in | |
83 | <filename>user.conf.d</filename> directories. See | |
84 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
85 | for more information.</para> | |
86 | </refsect1> | |
87 | ||
88 | <refsect1> | |
89 | <title>Options</title> | |
90 | ||
91 | <para>The following options are understood:</para> | |
92 | ||
93 | <variablelist> | |
94 | <varlistentry> | |
95 | <term><option>--test</option></term> | |
96 | ||
97 | <listitem><para>Determine startup sequence, dump it and exit. | |
98 | This is an option useful for debugging only.</para></listitem> | |
99 | </varlistentry> | |
100 | <varlistentry> | |
101 | <term><option>--dump-configuration-items</option></term> | |
102 | ||
103 | <listitem><para>Dump understood unit configuration items. This | |
104 | outputs a terse but complete list of configuration items | |
105 | understood in unit definition files.</para></listitem> | |
106 | </varlistentry> | |
107 | <varlistentry> | |
108 | <term><option>--unit=</option></term> | |
109 | ||
110 | <listitem><para>Set default unit to activate on startup. If | |
111 | not specified, defaults to | |
112 | <filename>default.target</filename>.</para></listitem> | |
113 | </varlistentry> | |
114 | <varlistentry> | |
115 | <term><option>--system</option></term> | |
116 | <term><option>--user</option></term> | |
117 | ||
118 | <listitem><para>For <option>--system</option>, tell systemd to | |
119 | run a system instance, even if the process ID is not 1, i.e. | |
120 | systemd is not run as init process. <option>--user</option> | |
121 | does the opposite, running a user instance even if the process | |
122 | ID is 1. Normally it should not be necessary to pass these | |
123 | options, as systemd automatically detects the mode it is | |
124 | started in. These options are hence of little use except for | |
125 | debugging. Note that it is not supported booting and | |
126 | maintaining a full system with systemd running in | |
127 | <option>--system</option> mode, but PID not 1. In practice, | |
128 | passing <option>--system</option> explicitly is only useful in | |
129 | conjunction with <option>--test</option>.</para></listitem> | |
130 | </varlistentry> | |
131 | <varlistentry> | |
132 | <term><option>--dump-core</option></term> | |
133 | ||
134 | <listitem><para>Dump core on crash. This switch has no effect | |
135 | when run as user instance.</para></listitem> | |
136 | </varlistentry> | |
137 | <varlistentry> | |
138 | <term><option>--crash-shell</option></term> | |
139 | ||
140 | <listitem><para>Run shell on | |
141 | crash. This switch has no effect when | |
142 | run as user | |
143 | instance.</para></listitem> | |
144 | </varlistentry> | |
145 | <varlistentry> | |
146 | <term><option>--confirm-spawn</option></term> | |
147 | ||
148 | <listitem><para>Ask for confirmation when spawning processes. | |
149 | This switch has no effect when run as user | |
150 | instance.</para></listitem> | |
151 | </varlistentry> | |
152 | <varlistentry> | |
153 | <term><option>--show-status=</option></term> | |
154 | ||
155 | <listitem><para>Show terse service status information while | |
156 | booting. This switch has no effect when run as user instance. | |
157 | Takes a boolean argument which may be omitted which is | |
158 | interpreted as <option>true</option>.</para></listitem> | |
159 | </varlistentry> | |
160 | <varlistentry> | |
161 | <term><option>--log-target=</option></term> | |
162 | ||
163 | <listitem><para>Set log target. Argument must be one of | |
164 | <option>console</option>, | |
165 | <option>journal</option>, | |
166 | <option>kmsg</option>, | |
167 | <option>journal-or-kmsg</option>, | |
168 | <option>null</option>.</para></listitem> | |
169 | </varlistentry> | |
170 | <varlistentry> | |
171 | <term><option>--log-level=</option></term> | |
172 | ||
173 | <listitem><para>Set log level. As | |
174 | argument this accepts a numerical log | |
175 | level or the well-known <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
176 | symbolic names (lowercase): | |
177 | <option>emerg</option>, | |
178 | <option>alert</option>, | |
179 | <option>crit</option>, | |
180 | <option>err</option>, | |
181 | <option>warning</option>, | |
182 | <option>notice</option>, | |
183 | <option>info</option>, | |
184 | <option>debug</option>.</para></listitem> | |
185 | </varlistentry> | |
186 | <varlistentry> | |
187 | <term><option>--log-color=</option></term> | |
188 | ||
189 | <listitem><para>Highlight important log messages. Argument is | |
190 | a boolean value. If the argument is omitted, it defaults to | |
191 | <option>true</option>.</para></listitem> | |
192 | </varlistentry> | |
193 | <varlistentry> | |
194 | <term><option>--log-location=</option></term> | |
195 | ||
196 | <listitem><para>Include code location in log messages. This is | |
197 | mostly relevant for debugging purposes. Argument is a boolean | |
198 | value. If the argument is omitted it defaults to | |
199 | <option>true</option>.</para></listitem> | |
200 | </varlistentry> | |
201 | <varlistentry> | |
202 | <term><option>--default-standard-output=</option></term> | |
203 | <term><option>--default-standard-error=</option></term> | |
204 | ||
205 | <listitem><para>Sets the default output or error output for | |
206 | all services and sockets, respectively. That is, controls the | |
207 | default for <option>StandardOutput=</option> and | |
208 | <option>StandardError=</option> (see | |
209 | <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
210 | for details). Takes one of | |
211 | <option>inherit</option>, | |
212 | <option>null</option>, | |
213 | <option>tty</option>, | |
214 | <option>journal</option>, | |
215 | <option>journal+console</option>, | |
216 | <option>syslog</option>, | |
217 | <option>syslog+console</option>, | |
218 | <option>kmsg</option>, | |
219 | <option>kmsg+console</option>. If the | |
220 | argument is omitted | |
221 | <option>--default-standard-output=</option> defaults to | |
222 | <option>journal</option> and | |
223 | <option>--default-standard-error=</option> to | |
224 | <option>inherit</option>.</para></listitem> | |
225 | </varlistentry> | |
226 | ||
227 | <xi:include href="standard-options.xml" xpointer="help" /> | |
228 | <xi:include href="standard-options.xml" xpointer="version" /> | |
229 | </variablelist> | |
230 | </refsect1> | |
231 | ||
232 | <refsect1> | |
233 | <title>Concepts</title> | |
234 | ||
235 | <para>systemd provides a dependency system between various | |
236 | entities called "units" of 12 different types. Units encapsulate | |
237 | various objects that are relevant for system boot-up and | |
238 | maintenance. The majority of units are configured in unit | |
239 | configuration files, whose syntax and basic set of options is | |
240 | described in | |
241 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
242 | however some are created automatically from other configuration, | |
243 | dynamically from system state or programmatically at runtime. | |
244 | Units may be "active" (meaning started, bound, plugged in, ..., | |
245 | depending on the unit type, see below), or "inactive" (meaning | |
246 | stopped, unbound, unplugged, ...), as well as in the process of | |
247 | being activated or deactivated, i.e. between the two states (these | |
248 | states are called "activating", "deactivating"). A special | |
249 | "failed" state is available as well, which is very similar to | |
250 | "inactive" and is entered when the service failed in some way | |
251 | (process returned error code on exit, or crashed, or an operation | |
252 | timed out). If this state is entered, the cause will be logged, | |
253 | for later reference. Note that the various unit types may have a | |
254 | number of additional substates, which are mapped to the five | |
255 | generalized unit states described here.</para> | |
256 | ||
257 | <para>The following unit types are available:</para> | |
258 | ||
259 | <orderedlist> | |
260 | <listitem><para>Service units, which start and control daemons | |
261 | and the processes they consist of. For details see | |
262 | <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
263 | ||
264 | <listitem><para>Socket units, which encapsulate local IPC or | |
265 | network sockets in the system, useful for socket-based | |
266 | activation. For details about socket units see | |
267 | <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
268 | for details on socket-based activation and other forms of | |
269 | activation, see | |
270 | <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para></listitem> | |
271 | ||
272 | <listitem><para>Target units are useful to group units, or | |
273 | provide well-known synchronization points during boot-up, see | |
274 | <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
275 | ||
276 | <listitem><para>Device units expose kernel devices in systemd | |
277 | and may be used to implement device-based activation. For | |
278 | details see | |
279 | <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
280 | ||
281 | <listitem><para>Mount units control mount points in the file | |
282 | system, for details see | |
283 | <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
284 | ||
285 | <listitem><para>Automount units provide automount capabilities, | |
286 | for on-demand mounting of file systems as well as parallelized | |
287 | boot-up. See | |
288 | <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
289 | ||
290 | <listitem><para>Snapshot units can be used to temporarily save | |
291 | the state of the set of systemd units, which later may be | |
292 | restored by activating the saved snapshot unit. For more | |
293 | information see | |
294 | <citerefentry><refentrytitle>systemd.snapshot</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
295 | ||
296 | <listitem><para>Timer units are useful for triggering activation | |
297 | of other units based on timers. You may find details in | |
298 | <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
299 | ||
300 | <listitem><para>Swap units are very similar to mount units and | |
301 | encapsulate memory swap partitions or files of the operating | |
302 | system. They are described in | |
303 | <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
304 | ||
305 | <listitem><para>Path units may be used to activate other | |
306 | services when file system objects change or are modified. See | |
307 | <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
308 | ||
309 | <listitem><para>Slice units may be used to group units which | |
310 | manage system processes (such as service and scope units) in a | |
311 | hierarchical tree for resource management purposes. See | |
312 | <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
313 | ||
314 | <listitem><para>Scope units are similar to service units, but | |
315 | manage foreign processes instead of starting them as well. See | |
316 | <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
317 | ||
318 | </orderedlist> | |
319 | ||
320 | <para>Units are named as their configuration files. Some units | |
321 | have special semantics. A detailed list is available in | |
322 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> | |
323 | ||
324 | <para>systemd knows various kinds of dependencies, including | |
325 | positive and negative requirement dependencies (i.e. | |
326 | <varname>Requires=</varname> and <varname>Conflicts=</varname>) as | |
327 | well as ordering dependencies (<varname>After=</varname> and | |
328 | <varname>Before=</varname>). NB: ordering and requirement | |
329 | dependencies are orthogonal. If only a requirement dependency | |
330 | exists between two units (e.g. <filename>foo.service</filename> | |
331 | requires <filename>bar.service</filename>), but no ordering | |
332 | dependency (e.g. <filename>foo.service</filename> after | |
333 | <filename>bar.service</filename>) and both are requested to start, | |
334 | they will be started in parallel. It is a common pattern that both | |
335 | requirement and ordering dependencies are placed between two | |
336 | units. Also note that the majority of dependencies are implicitly | |
337 | created and maintained by systemd. In most cases, it should be | |
338 | unnecessary to declare additional dependencies manually, however | |
339 | it is possible to do this.</para> | |
340 | ||
341 | <para>Application programs and units (via dependencies) may | |
342 | request state changes of units. In systemd, these requests are | |
343 | encapsulated as 'jobs' and maintained in a job queue. Jobs may | |
344 | succeed or can fail, their execution is ordered based on the | |
345 | ordering dependencies of the units they have been scheduled | |
346 | for.</para> | |
347 | ||
348 | <para>On boot systemd activates the target unit | |
349 | <filename>default.target</filename> whose job is to activate | |
350 | on-boot services and other on-boot units by pulling them in via | |
351 | dependencies. Usually the unit name is just an alias (symlink) for | |
352 | either <filename>graphical.target</filename> (for fully-featured | |
353 | boots into the UI) or <filename>multi-user.target</filename> (for | |
354 | limited console-only boots for use in embedded or server | |
355 | environments, or similar; a subset of graphical.target). However, | |
356 | it is at the discretion of the administrator to configure it as an | |
357 | alias to any other target unit. See | |
358 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
359 | for details about these target units.</para> | |
360 | ||
361 | <para>Processes systemd spawns are placed in individual Linux | |
362 | control groups named after the unit which they belong to in the | |
363 | private systemd hierarchy. (see <ulink | |
364 | url="https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink> | |
365 | for more information about control groups, or short "cgroups"). | |
366 | systemd uses this to effectively keep track of processes. Control | |
367 | group information is maintained in the kernel, and is accessible | |
368 | via the file system hierarchy (beneath | |
369 | <filename>/sys/fs/cgroup/systemd/</filename>), or in tools such as | |
370 | <citerefentry project='man-pages'><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
371 | (<command>ps xawf -eo pid,user,cgroup,args</command> is | |
372 | particularly useful to list all processes and the systemd units | |
373 | they belong to.).</para> | |
374 | ||
375 | <para>systemd is compatible with the SysV init system to a large | |
376 | degree: SysV init scripts are supported and simply read as an | |
377 | alternative (though limited) configuration file format. The SysV | |
378 | <filename>/dev/initctl</filename> interface is provided, and | |
379 | compatibility implementations of the various SysV client tools are | |
380 | available. In addition to that, various established Unix | |
381 | functionality such as <filename>/etc/fstab</filename> or the | |
382 | <filename>utmp</filename> database are supported.</para> | |
383 | ||
384 | <para>systemd has a minimal transaction system: if a unit is | |
385 | requested to start up or shut down it will add it and all its | |
386 | dependencies to a temporary transaction. Then, it will verify if | |
387 | the transaction is consistent (i.e. whether the ordering of all | |
388 | units is cycle-free). If it is not, systemd will try to fix it up, | |
389 | and removes non-essential jobs from the transaction that might | |
390 | remove the loop. Also, systemd tries to suppress non-essential | |
391 | jobs in the transaction that would stop a running service. Finally | |
392 | it is checked whether the jobs of the transaction contradict jobs | |
393 | that have already been queued, and optionally the transaction is | |
394 | aborted then. If all worked out and the transaction is consistent | |
395 | and minimized in its impact it is merged with all already | |
396 | outstanding jobs and added to the run queue. Effectively this | |
397 | means that before executing a requested operation, systemd will | |
398 | verify that it makes sense, fixing it if possible, and only | |
399 | failing if it really cannot work.</para> | |
400 | ||
401 | <para>Systemd contains native implementations of various tasks | |
402 | that need to be executed as part of the boot process. For example, | |
403 | it sets the hostname or configures the loopback network device. It | |
404 | also sets up and mounts various API file systems, such as | |
405 | <filename>/sys</filename> or <filename>/proc</filename>.</para> | |
406 | ||
407 | <para>For more information about the concepts and | |
408 | ideas behind systemd, please refer to the | |
409 | <ulink url="http://0pointer.de/blog/projects/systemd.html">Original Design Document</ulink>.</para> | |
410 | ||
411 | <para>Note that some but not all interfaces provided | |
412 | by systemd are covered by the | |
413 | <ulink url="http://www.freedesktop.org/wiki/Software/systemd/InterfaceStabilityPromise">Interface | |
414 | Stability Promise</ulink>.</para> | |
415 | ||
416 | <para>Units may be generated dynamically at boot and system | |
417 | manager reload time, for example based on other configuration | |
418 | files or parameters passed on the kernel command line. For details | |
419 | see the | |
420 | <ulink url="http://www.freedesktop.org/wiki/Software/systemd/Generators">Generators Specification</ulink>.</para> | |
421 | ||
422 | <para>Systems which invoke systemd in a container or initrd | |
423 | environment should implement the | |
424 | <ulink url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container Interface</ulink> or | |
425 | <ulink url="http://www.freedesktop.org/wiki/Software/systemd/InitrdInterface">initrd Interface</ulink> | |
426 | specifications, respectively.</para> | |
427 | </refsect1> | |
428 | ||
429 | <refsect1> | |
430 | <title>Directories</title> | |
431 | ||
432 | <variablelist> | |
433 | <varlistentry> | |
434 | <term>System unit directories</term> | |
435 | ||
436 | <listitem><para>The systemd system manager reads unit | |
437 | configuration from various directories. Packages that want to | |
438 | install unit files shall place them in the directory returned | |
439 | by <command>pkg-config systemd | |
440 | --variable=systemdsystemunitdir</command>. Other directories | |
441 | checked are <filename>/usr/local/lib/systemd/system</filename> | |
442 | and <filename>/usr/lib/systemd/system</filename>. User | |
443 | configuration always takes precedence. <command>pkg-config | |
444 | systemd --variable=systemdsystemconfdir</command> returns the | |
445 | path of the system configuration directory. Packages should | |
446 | alter the content of these directories only with the | |
447 | <command>enable</command> and <command>disable</command> | |
448 | commands of the | |
449 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
450 | tool. Full list of directories is provided in | |
451 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
452 | </para></listitem> | |
453 | </varlistentry> | |
454 | </variablelist> | |
455 | ||
456 | <variablelist> | |
457 | <varlistentry> | |
458 | <term>User unit directories</term> | |
459 | ||
460 | <listitem><para>Similar rules apply for the user unit | |
461 | directories. However, here the | |
462 | <ulink url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG | |
463 | Base Directory specification</ulink> is followed to find | |
464 | units. Applications should place their unit files in the | |
465 | directory returned by <command>pkg-config systemd | |
466 | --variable=systemduserunitdir</command>. Global configuration | |
467 | is done in the directory reported by <command>pkg-config | |
468 | systemd --variable=systemduserconfdir</command>. The | |
469 | <command>enable</command> and <command>disable</command> | |
470 | commands of the | |
471 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
472 | tool can handle both global (i.e. for all users) and private | |
473 | (for one user) enabling/disabling of units. Full list of | |
474 | directories is provided in | |
475 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
476 | </para></listitem> | |
477 | </varlistentry> | |
478 | </variablelist> | |
479 | ||
480 | <variablelist> | |
481 | <varlistentry> | |
482 | <term>SysV init scripts directory</term> | |
483 | ||
484 | <listitem><para>The location of the SysV init script directory | |
485 | varies between distributions. If systemd cannot find a native | |
486 | unit file for a requested service, it will look for a SysV | |
487 | init script of the same name (with the | |
488 | <filename>.service</filename> suffix | |
489 | removed).</para></listitem> | |
490 | </varlistentry> | |
491 | </variablelist> | |
492 | ||
493 | <variablelist> | |
494 | <varlistentry> | |
495 | <term>SysV runlevel link farm directory</term> | |
496 | ||
497 | <listitem><para>The location of the SysV runlevel link farm | |
498 | directory varies between distributions. systemd will take the | |
499 | link farm into account when figuring out whether a service | |
500 | shall be enabled. Note that a service unit with a native unit | |
501 | configuration file cannot be started by activating it in the | |
502 | SysV runlevel link farm.</para></listitem> | |
503 | </varlistentry> | |
504 | </variablelist> | |
505 | </refsect1> | |
506 | ||
507 | <refsect1> | |
508 | <title>Signals</title> | |
509 | ||
510 | <variablelist> | |
511 | <varlistentry> | |
512 | <term><constant>SIGTERM</constant></term> | |
513 | ||
514 | <listitem><para>Upon receiving this signal the systemd system | |
515 | manager serializes its state, reexecutes itself and | |
516 | deserializes the saved state again. This is mostly equivalent | |
517 | to <command>systemctl daemon-reexec</command>.</para> | |
518 | ||
519 | <para>systemd user managers will start the | |
520 | <filename>exit.target</filename> unit when this signal is | |
521 | received. This is mostly equivalent to <command>systemctl | |
522 | --user start exit.target</command>.</para></listitem> | |
523 | </varlistentry> | |
524 | ||
525 | <varlistentry> | |
526 | <term><constant>SIGINT</constant></term> | |
527 | ||
528 | <listitem><para>Upon receiving this signal the systemd system | |
529 | manager will start the | |
530 | <filename>ctrl-alt-del.target</filename> unit. This is mostly | |
531 | equivalent to <command>systemctl start | |
532 | ctl-alt-del.target</command>. If this signal is received more | |
533 | often than 7 times per 2s an immediate reboot is triggered. | |
534 | Note that pressing Ctrl-Alt-Del on the console will trigger | |
535 | this signal. Hence, if a reboot is hanging pressing | |
536 | Ctrl-Alt-Del more than 7 times in 2s is a relatively safe way | |
537 | to trigger an immediate reboot.</para> | |
538 | ||
539 | <para>systemd user managers treat this signal the same way as | |
540 | <constant>SIGTERM</constant>.</para></listitem> | |
541 | </varlistentry> | |
542 | ||
543 | <varlistentry> | |
544 | <term><constant>SIGWINCH</constant></term> | |
545 | ||
546 | <listitem><para>When this signal is received the systemd | |
547 | system manager will start the | |
548 | <filename>kbrequest.target</filename> unit. This is mostly | |
549 | equivalent to <command>systemctl start | |
550 | kbrequest.target</command>.</para> | |
551 | ||
552 | <para>This signal is ignored by systemd user | |
553 | managers.</para></listitem> | |
554 | </varlistentry> | |
555 | ||
556 | <varlistentry> | |
557 | <term><constant>SIGPWR</constant></term> | |
558 | ||
559 | <listitem><para>When this signal is received the systemd | |
560 | manager will start the <filename>sigpwr.target</filename> | |
561 | unit. This is mostly equivalent to <command>systemctl start | |
562 | sigpwr.target</command>.</para></listitem> | |
563 | </varlistentry> | |
564 | ||
565 | <varlistentry> | |
566 | <term><constant>SIGUSR1</constant></term> | |
567 | ||
568 | <listitem><para>When this signal is received the systemd | |
569 | manager will try to reconnect to the D-Bus | |
570 | bus.</para></listitem> | |
571 | </varlistentry> | |
572 | ||
573 | <varlistentry> | |
574 | <term><constant>SIGUSR2</constant></term> | |
575 | ||
576 | <listitem><para>When this signal is received the systemd | |
577 | manager will log its complete state in human readable form. | |
578 | The data logged is the same as printed by | |
579 | <command>systemd-analyze dump</command>.</para></listitem> | |
580 | </varlistentry> | |
581 | ||
582 | <varlistentry> | |
583 | <term><constant>SIGHUP</constant></term> | |
584 | ||
585 | <listitem><para>Reloads the complete daemon configuration. | |
586 | This is mostly equivalent to <command>systemctl | |
587 | daemon-reload</command>.</para></listitem> | |
588 | </varlistentry> | |
589 | ||
590 | <varlistentry> | |
591 | <term><constant>SIGRTMIN+0</constant></term> | |
592 | ||
593 | <listitem><para>Enters default mode, starts the | |
594 | <filename>default.target</filename> unit. This is mostly | |
595 | equivalent to <command>systemctl start | |
596 | default.target</command>.</para></listitem> | |
597 | </varlistentry> | |
598 | ||
599 | <varlistentry> | |
600 | <term><constant>SIGRTMIN+1</constant></term> | |
601 | ||
602 | <listitem><para>Enters rescue mode, starts the | |
603 | <filename>rescue.target</filename> unit. This is mostly | |
604 | equivalent to <command>systemctl isolate | |
605 | rescue.target</command>.</para></listitem> | |
606 | </varlistentry> | |
607 | ||
608 | <varlistentry> | |
609 | <term><constant>SIGRTMIN+2</constant></term> | |
610 | ||
611 | <listitem><para>Enters emergency mode, starts the | |
612 | <filename>emergency.service</filename> unit. This is mostly | |
613 | equivalent to <command>systemctl isolate | |
614 | emergency.service</command>.</para></listitem> | |
615 | </varlistentry> | |
616 | ||
617 | <varlistentry> | |
618 | <term><constant>SIGRTMIN+3</constant></term> | |
619 | ||
620 | <listitem><para>Halts the machine, starts the | |
621 | <filename>halt.target</filename> unit. This is mostly | |
622 | equivalent to <command>systemctl start | |
623 | halt.target</command>.</para></listitem> | |
624 | </varlistentry> | |
625 | ||
626 | <varlistentry> | |
627 | <term><constant>SIGRTMIN+4</constant></term> | |
628 | ||
629 | <listitem><para>Powers off the machine, starts the | |
630 | <filename>poweroff.target</filename> unit. This is mostly | |
631 | equivalent to <command>systemctl start | |
632 | poweroff.target</command>.</para></listitem> | |
633 | </varlistentry> | |
634 | ||
635 | <varlistentry> | |
636 | <term><constant>SIGRTMIN+5</constant></term> | |
637 | ||
638 | <listitem><para>Reboots the machine, starts the | |
639 | <filename>reboot.target</filename> unit. This is mostly | |
640 | equivalent to <command>systemctl start | |
641 | reboot.target</command>.</para></listitem> | |
642 | </varlistentry> | |
643 | ||
644 | <varlistentry> | |
645 | <term><constant>SIGRTMIN+6</constant></term> | |
646 | ||
647 | <listitem><para>Reboots the machine via kexec, starts the | |
648 | <filename>kexec.target</filename> unit. This is mostly | |
649 | equivalent to <command>systemctl start | |
650 | kexec.target</command>.</para></listitem> | |
651 | </varlistentry> | |
652 | ||
653 | <varlistentry> | |
654 | <term><constant>SIGRTMIN+13</constant></term> | |
655 | ||
656 | <listitem><para>Immediately halts the machine.</para></listitem> | |
657 | </varlistentry> | |
658 | ||
659 | <varlistentry> | |
660 | <term><constant>SIGRTMIN+14</constant></term> | |
661 | ||
662 | <listitem><para>Immediately powers off the machine.</para></listitem> | |
663 | </varlistentry> | |
664 | ||
665 | <varlistentry> | |
666 | <term><constant>SIGRTMIN+15</constant></term> | |
667 | ||
668 | <listitem><para>Immediately reboots the machine.</para></listitem> | |
669 | </varlistentry> | |
670 | ||
671 | <varlistentry> | |
672 | <term><constant>SIGRTMIN+16</constant></term> | |
673 | ||
674 | <listitem><para>Immediately reboots the machine with kexec.</para></listitem> | |
675 | </varlistentry> | |
676 | ||
677 | <varlistentry> | |
678 | <term><constant>SIGRTMIN+20</constant></term> | |
679 | ||
680 | <listitem><para>Enables display of status messages on the | |
681 | console, as controlled via | |
682 | <varname>systemd.show_status=1</varname> on the kernel command | |
683 | line.</para></listitem> | |
684 | </varlistentry> | |
685 | ||
686 | <varlistentry> | |
687 | <term><constant>SIGRTMIN+21</constant></term> | |
688 | ||
689 | <listitem><para>Disables display of | |
690 | status messages on the console, as | |
691 | controlled via | |
692 | <varname>systemd.show_status=0</varname> | |
693 | on the kernel command | |
694 | line.</para></listitem> | |
695 | </varlistentry> | |
696 | ||
697 | <varlistentry> | |
698 | <term><constant>SIGRTMIN+22</constant></term> | |
699 | <term><constant>SIGRTMIN+23</constant></term> | |
700 | ||
701 | <listitem><para>Sets the log level to <literal>debug</literal> | |
702 | (or <literal>info</literal> on | |
703 | <constant>SIGRTMIN+23</constant>), as controlled via | |
704 | <varname>systemd.log_level=debug</varname> (or | |
705 | <varname>systemd.log_level=info</varname> on | |
706 | <constant>SIGRTMIN+23</constant>) on the kernel command | |
707 | line.</para></listitem> | |
708 | </varlistentry> | |
709 | ||
710 | <varlistentry> | |
711 | <term><constant>SIGRTMIN+24</constant></term> | |
712 | ||
713 | <listitem><para>Immediately exits the manager (only available | |
714 | for --user instances).</para></listitem> | |
715 | </varlistentry> | |
716 | ||
717 | <varlistentry> | |
718 | <term><constant>SIGRTMIN+26</constant></term> | |
719 | <term><constant>SIGRTMIN+27</constant></term> | |
720 | <term><constant>SIGRTMIN+28</constant></term> | |
721 | ||
722 | <listitem><para>Sets the log level to | |
723 | <literal>journal-or-kmsg</literal> (or | |
724 | <literal>console</literal> on | |
725 | <constant>SIGRTMIN+27</constant>, <literal>kmsg</literal> on | |
726 | <constant>SIGRTMIN+28</constant>), as controlled via | |
727 | <varname>systemd.log_target=journal-or-kmsg</varname> (or | |
728 | <varname>systemd.log_target=console</varname> on | |
729 | <constant>SIGRTMIN+27</constant> or | |
730 | <varname>systemd.log_target=kmsg</varname> on | |
731 | <constant>SIGRTMIN+28</constant>) on the kernel command | |
732 | line.</para></listitem> | |
733 | </varlistentry> | |
734 | </variablelist> | |
735 | </refsect1> | |
736 | ||
737 | <refsect1> | |
738 | <title>Environment</title> | |
739 | ||
740 | <variablelist class='environment-variables'> | |
741 | <varlistentry> | |
742 | <term><varname>$SYSTEMD_LOG_LEVEL</varname></term> | |
743 | <listitem><para>systemd reads the log level from this | |
744 | environment variable. This can be overridden with | |
745 | <option>--log-level=</option>.</para></listitem> | |
746 | </varlistentry> | |
747 | ||
748 | <varlistentry> | |
749 | <term><varname>$SYSTEMD_LOG_TARGET</varname></term> | |
750 | <listitem><para>systemd reads the log target from this | |
751 | environment variable. This can be overridden with | |
752 | <option>--log-target=</option>.</para></listitem> | |
753 | </varlistentry> | |
754 | ||
755 | <varlistentry> | |
756 | <term><varname>$SYSTEMD_LOG_COLOR</varname></term> | |
757 | <listitem><para>Controls whether systemd highlights important | |
758 | log messages. This can be overridden with | |
759 | <option>--log-color=</option>.</para></listitem> | |
760 | </varlistentry> | |
761 | ||
762 | <varlistentry> | |
763 | <term><varname>$SYSTEMD_LOG_LOCATION</varname></term> | |
764 | <listitem><para>Controls whether systemd prints the code | |
765 | location along with log messages. This can be overridden with | |
766 | <option>--log-location=</option>.</para></listitem> | |
767 | </varlistentry> | |
768 | ||
769 | <varlistentry> | |
770 | <term><varname>$XDG_CONFIG_HOME</varname></term> | |
771 | <term><varname>$XDG_CONFIG_DIRS</varname></term> | |
772 | <term><varname>$XDG_DATA_HOME</varname></term> | |
773 | <term><varname>$XDG_DATA_DIRS</varname></term> | |
774 | ||
775 | <listitem><para>The systemd user manager uses these variables | |
776 | in accordance to the <ulink | |
777 | url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG | |
778 | Base Directory specification</ulink> to find its | |
779 | configuration.</para></listitem> | |
780 | </varlistentry> | |
781 | ||
782 | <varlistentry> | |
783 | <term><varname>$SYSTEMD_UNIT_PATH</varname></term> | |
784 | ||
785 | <listitem><para>Controls where systemd looks for unit | |
786 | files.</para></listitem> | |
787 | </varlistentry> | |
788 | ||
789 | <varlistentry> | |
790 | <term><varname>$SYSTEMD_SYSVINIT_PATH</varname></term> | |
791 | ||
792 | <listitem><para>Controls where systemd looks for SysV init | |
793 | scripts.</para></listitem> | |
794 | </varlistentry> | |
795 | ||
796 | <varlistentry> | |
797 | <term><varname>$SYSTEMD_SYSVRCND_PATH</varname></term> | |
798 | ||
799 | <listitem><para>Controls where systemd looks for SysV init | |
800 | script runlevel link farms.</para></listitem> | |
801 | </varlistentry> | |
802 | ||
803 | <varlistentry> | |
804 | <term><varname>$LISTEN_PID</varname></term> | |
805 | <term><varname>$LISTEN_FDS</varname></term> | |
806 | ||
807 | <listitem><para>Set by systemd for supervised processes during | |
808 | socket-based activation. See | |
809 | <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
810 | for more information. </para></listitem> | |
811 | </varlistentry> | |
812 | ||
813 | <varlistentry> | |
814 | <term><varname>$NOTIFY_SOCKET</varname></term> | |
815 | ||
816 | <listitem><para>Set by systemd for supervised processes for | |
817 | status and start-up completion notification. See | |
818 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
819 | for more information. </para></listitem> | |
820 | </varlistentry> | |
821 | </variablelist> | |
822 | </refsect1> | |
823 | ||
824 | <refsect1> | |
825 | <title>Kernel Command Line</title> | |
826 | ||
827 | <para>When run as system instance systemd parses a number of | |
828 | kernel command line arguments<footnote><para>If run inside a Linux | |
829 | container these arguments may be passed as command line arguments | |
830 | to systemd itself, next to any of the command line options listed | |
831 | in the Options section above. If run outside of Linux containers, | |
832 | these arguments are parsed from <filename>/proc/cmdline</filename> | |
833 | instead.</para></footnote>:</para> | |
834 | ||
835 | <variablelist class='kernel-commandline-options'> | |
836 | <varlistentry> | |
837 | <term><varname>systemd.unit=</varname></term> | |
838 | <term><varname>rd.systemd.unit=</varname></term> | |
839 | ||
840 | <listitem><para>Overrides the unit to activate on boot. | |
841 | Defaults to <filename>default.target</filename>. This may be | |
842 | used to temporarily boot into a different boot unit, for | |
843 | example <filename>rescue.target</filename> or | |
844 | <filename>emergency.service</filename>. See | |
845 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
846 | for details about these units. The option prefixed with | |
847 | <literal>rd.</literal> is honored only in the initial RAM disk | |
848 | (initrd), while the one that is not prefixed only in the main | |
849 | system.</para></listitem> | |
850 | </varlistentry> | |
851 | ||
852 | <varlistentry> | |
853 | <term><varname>systemd.dump_core=</varname></term> | |
854 | ||
855 | <listitem><para>Takes a boolean argument. If | |
856 | <option>true</option>, systemd dumps core when it crashes. | |
857 | Otherwise, no core dump is created. Defaults to | |
858 | <option>true</option>.</para></listitem> | |
859 | </varlistentry> | |
860 | ||
861 | <varlistentry> | |
862 | <term><varname>systemd.crash_shell=</varname></term> | |
863 | ||
864 | <listitem><para>Takes a boolean argument. If | |
865 | <option>true</option>, systemd spawns a shell when it crashes. | |
866 | Otherwise, no shell is spawned. Defaults to | |
867 | <option>false</option>, for security reasons, as the shell is | |
868 | not protected by any password | |
869 | authentication.</para></listitem> | |
870 | </varlistentry> | |
871 | ||
872 | <varlistentry> | |
873 | <term><varname>systemd.crash_chvt=</varname></term> | |
874 | ||
875 | <listitem><para>Takes an integer argument. If positive systemd | |
876 | activates the specified virtual terminal when it crashes. | |
877 | Defaults to <constant>-1</constant>.</para></listitem> | |
878 | </varlistentry> | |
879 | ||
880 | <varlistentry> | |
881 | <term><varname>systemd.confirm_spawn=</varname></term> | |
882 | ||
883 | <listitem><para>Takes a boolean argument. If | |
884 | <option>true</option>, asks for confirmation when spawning | |
885 | processes. Defaults to | |
886 | <option>false</option>.</para></listitem> | |
887 | </varlistentry> | |
888 | ||
889 | <varlistentry> | |
890 | <term><varname>systemd.show_status=</varname></term> | |
891 | ||
892 | <listitem><para>Takes a boolean argument or the constant | |
893 | <constant>auto</constant>. If <option>true</option>, shows | |
894 | terse service status updates on the console during bootup. | |
895 | <constant>auto</constant> behaves like <option>false</option> | |
896 | until a service fails or there is a significant delay in boot. | |
897 | Defaults to <option>true</option>, unless | |
898 | <option>quiet</option> is passed as kernel command line option | |
899 | in which case it defaults to | |
900 | <constant>auto</constant>.</para></listitem> | |
901 | </varlistentry> | |
902 | ||
903 | <varlistentry> | |
904 | <term><varname>systemd.log_target=</varname></term> | |
905 | <term><varname>systemd.log_level=</varname></term> | |
906 | <term><varname>systemd.log_color=</varname></term> | |
907 | <term><varname>systemd.log_location=</varname></term> | |
908 | ||
909 | <listitem><para>Controls log output, with the same effect as | |
910 | the <varname>$SYSTEMD_LOG_TARGET</varname>, | |
911 | <varname>$SYSTEMD_LOG_LEVEL</varname>, | |
912 | <varname>$SYSTEMD_LOG_COLOR</varname>, | |
913 | <varname>$SYSTEMD_LOG_LOCATION</varname> environment variables | |
914 | described above.</para></listitem> | |
915 | </varlistentry> | |
916 | ||
917 | <varlistentry> | |
918 | <term><varname>systemd.default_standard_output=</varname></term> | |
919 | <term><varname>systemd.default_standard_error=</varname></term> | |
920 | <listitem><para>Controls default standard output and error | |
921 | output for services, with the same effect as the | |
922 | <option>--default-standard-output=</option> and | |
923 | <option>--default-standard-error=</option> command line | |
924 | arguments described above, respectively.</para></listitem> | |
925 | </varlistentry> | |
926 | ||
927 | <varlistentry> | |
928 | <term><varname>systemd.setenv=</varname></term> | |
929 | ||
930 | <listitem><para>Takes a string argument in the form | |
931 | VARIABLE=VALUE. May be used to set default environment | |
932 | variables to add to forked child processes. May be used more | |
933 | than once to set multiple variables.</para></listitem> | |
934 | </varlistentry> | |
935 | ||
936 | <varlistentry> | |
937 | <term><varname>quiet</varname></term> | |
938 | ||
939 | <listitem><para>Turn off status output at boot, much like | |
940 | <varname>systemd.show_status=false</varname> would. Note that | |
941 | this option is also read by the kernel itself and disables | |
942 | kernel log output. Passing this option hence turns off the | |
943 | usual output from both the system manager and the kernel. | |
944 | </para></listitem> | |
945 | </varlistentry> | |
946 | ||
947 | <varlistentry> | |
948 | <term><varname>debug</varname></term> | |
949 | ||
950 | <listitem><para>Turn on debugging output. This is equivalent | |
951 | to <varname>systemd.log_level=debug</varname>. Note that this | |
952 | option is also read by the kernel itself and enables kernel | |
953 | debug output. Passing this option hence turns on the debug | |
954 | output from both the system manager and the | |
955 | kernel.</para></listitem> | |
956 | </varlistentry> | |
957 | ||
958 | <varlistentry> | |
959 | <term><varname>emergency</varname></term> | |
960 | <term><varname>-b</varname></term> | |
961 | ||
962 | <listitem><para>Boot into emergency mode. This is equivalent | |
963 | to <varname>systemd.unit=emergency.target</varname> and | |
964 | provided for compatibility reasons and to be easier to | |
965 | type.</para></listitem> | |
966 | </varlistentry> | |
967 | ||
968 | <varlistentry> | |
969 | <term><varname>rescue</varname></term> | |
970 | <term><varname>single</varname></term> | |
971 | <term><varname>s</varname></term> | |
972 | <term><varname>S</varname></term> | |
973 | <term><varname>1</varname></term> | |
974 | ||
975 | <listitem><para>Boot into rescue mode. This is equivalent to | |
976 | <varname>systemd.unit=rescue.target</varname> and provided for | |
977 | compatibility reasons and to be easier to | |
978 | type.</para></listitem> | |
979 | </varlistentry> | |
980 | ||
981 | <varlistentry> | |
982 | <term><varname>2</varname></term> | |
983 | <term><varname>3</varname></term> | |
984 | <term><varname>4</varname></term> | |
985 | <term><varname>5</varname></term> | |
986 | ||
987 | <listitem><para>Boot into the specified legacy SysV runlevel. | |
988 | These are equivalent to | |
989 | <varname>systemd.unit=runlevel2.target</varname>, | |
990 | <varname>systemd.unit=runlevel3.target</varname>, | |
991 | <varname>systemd.unit=runlevel4.target</varname>, and | |
992 | <varname>systemd.unit=runlevel5.target</varname>, | |
993 | respectively, and provided for compatibility reasons and to be | |
994 | easier to type.</para></listitem> | |
995 | </varlistentry> | |
996 | ||
997 | <varlistentry> | |
998 | <term><varname>locale.LANG=</varname></term> | |
999 | <term><varname>locale.LANGUAGE=</varname></term> | |
1000 | <term><varname>locale.LC_CTYPE=</varname></term> | |
1001 | <term><varname>locale.LC_NUMERIC=</varname></term> | |
1002 | <term><varname>locale.LC_TIME=</varname></term> | |
1003 | <term><varname>locale.LC_COLLATE=</varname></term> | |
1004 | <term><varname>locale.LC_MONETARY=</varname></term> | |
1005 | <term><varname>locale.LC_MESSAGES=</varname></term> | |
1006 | <term><varname>locale.LC_PAPER=</varname></term> | |
1007 | <term><varname>locale.LC_NAME=</varname></term> | |
1008 | <term><varname>locale.LC_ADDRESS=</varname></term> | |
1009 | <term><varname>locale.LC_TELEPHONE=</varname></term> | |
1010 | <term><varname>locale.LC_MEASUREMENT=</varname></term> | |
1011 | <term><varname>locale.LC_IDENTIFICATION=</varname></term> | |
1012 | ||
1013 | <listitem><para>Set the system locale to use. This overrides | |
1014 | the settings in <filename>/etc/locale.conf</filename>. For | |
1015 | more information see | |
1016 | <citerefentry><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
1017 | and | |
1018 | <citerefentry><refentrytitle>locale</refentrytitle><manvolnum>7</manvolnum></citerefentry>. | |
1019 | </para></listitem> | |
1020 | </varlistentry> | |
1021 | </variablelist> | |
1022 | ||
1023 | <para>For other kernel command line parameters understood by | |
1024 | components of the core OS, please refer to | |
1025 | <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> | |
1026 | </refsect1> | |
1027 | ||
1028 | <refsect1> | |
1029 | <title>Sockets and FIFOs</title> | |
1030 | ||
1031 | <variablelist> | |
1032 | <varlistentry> | |
1033 | <term><filename>/run/systemd/notify</filename></term> | |
1034 | ||
1035 | <listitem><para>Daemon status notification socket. This is an | |
1036 | <constant>AF_UNIX</constant> datagram socket and is used to | |
1037 | implement the daemon notification logic as implemented by | |
1038 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> | |
1039 | ||
1040 | </varlistentry> | |
1041 | ||
1042 | <varlistentry> | |
1043 | <term><filename>/run/systemd/shutdownd</filename></term> | |
1044 | ||
1045 | <listitem><para>Used internally by the | |
1046 | <citerefentry><refentrytitle>shutdown</refentrytitle><manvolnum>8</manvolnum></citerefentry> | |
1047 | tool to implement delayed shutdowns. This is an | |
1048 | <constant>AF_UNIX</constant> datagram | |
1049 | socket.</para></listitem> | |
1050 | </varlistentry> | |
1051 | ||
1052 | <varlistentry> | |
1053 | <term><filename>/run/systemd/private</filename></term> | |
1054 | ||
1055 | <listitem><para>Used internally as communication channel | |
1056 | between | |
1057 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
1058 | and the systemd process. This is an | |
1059 | <constant>AF_UNIX</constant> stream socket. This interface is | |
1060 | private to systemd and should not be used in external | |
1061 | projects.</para></listitem> | |
1062 | </varlistentry> | |
1063 | ||
1064 | <varlistentry> | |
1065 | <term><filename>/dev/initctl</filename></term> | |
1066 | ||
1067 | <listitem><para>Limited compatibility support for the SysV | |
1068 | client interface, as implemented by the | |
1069 | <filename>systemd-initctl.service</filename> unit. This is a | |
1070 | named pipe in the file system. This interface is obsolete and | |
1071 | should not be used in new applications.</para></listitem> | |
1072 | </varlistentry> | |
1073 | </variablelist> | |
1074 | </refsect1> | |
1075 | ||
1076 | <refsect1> | |
1077 | <title>See Also</title> | |
1078 | <para> | |
1079 | The <ulink url="http://www.freedesktop.org/wiki/Software/systemd/">systemd Homepage</ulink>, | |
1080 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1081 | <citerefentry><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1082 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
1083 | <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
1084 | <citerefentry><refentrytitle>systemd-notify</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
1085 | <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>, | |
1086 | <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>, | |
1087 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1088 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
1089 | <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
1090 | <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>, | |
1091 | <citerefentry project='man-pages'><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>, | |
1092 | <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
1093 | </para> | |
1094 | </refsect1> | |
663996b3 MS |
1095 | |
1096 | </refentry> |