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1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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 General Public License as published by
12   the Free Software Foundation; either version 2 of the License, or
13   (at your option) any later version.
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18   General Public License for more details.
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20   You should have received a copy of the GNU General Public License
21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 -->
23
24 <refentry id="systemctl">
25
26         <refentryinfo>
27                 <title>systemctl</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>systemctl</refentrytitle>
42                 <manvolnum>1</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>systemctl</refname>
47                 <refpurpose>Control the systemd system and session manager</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <cmdsynopsis>
52                         <command>systemctl <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg> <arg choice="opt" rep="repeat">NAME</arg></command>
53                 </cmdsynopsis>
54         </refsynopsisdiv>
55
56         <refsect1>
57                 <title>Description</title>
58
59                 <para><command>systemctl</command> may be used to
60                 introspect and control the state of the
61                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
62                 system and session manager.</para>
63         </refsect1>
64
65         <refsect1>
66                 <title>Options</title>
67
68                 <para>The following options are understood:</para>
69
70                 <variablelist>
71                         <varlistentry>
72                                 <term><option>--help</option></term>
73                                 <term><option>-h</option></term>
74
75                                 <listitem><para>Prints a short help
76                                 text and exits.</para></listitem>
77                         </varlistentry>
78
79                         <varlistentry>
80                                 <term><option>--version</option></term>
81
82                                 <listitem><para>Prints a short version
83                                 string and exits.</para></listitem>
84                         </varlistentry>
85
86                         <varlistentry>
87                                 <term><option>--type=</option></term>
88                                 <term><option>-t</option></term>
89
90                                 <listitem><para>When listing units,
91                                 limit display to certain unit
92                                 types. If not specified units of all
93                                 types will be shown. The argument
94                                 should be a unit type name such as
95                                 <option>service</option>,
96                                 <option>socket</option> and
97                                 similar.</para></listitem>
98                         </varlistentry>
99
100                         <varlistentry>
101                                 <term><option>--property=</option></term>
102                                 <term><option>-p</option></term>
103
104                                 <listitem><para>When showing
105                                 unit/job/manager information, limit
106                                 display to certain properties as
107                                 specified as argument. If not
108                                 specified all set properties are
109                                 shown. The argument should be a
110                                 property name, such as
111                                 <literal>MainPID</literal>. If
112                                 specified more than once all
113                                 properties with the specified names
114                                 are shown.</para></listitem>
115                         </varlistentry>
116
117                         <varlistentry>
118                                 <term><option>--all</option></term>
119                                 <term><option>-a</option></term>
120
121                                 <listitem><para>When listing units,
122                                 show all units, regardless of their
123                                 state, including inactive units. When
124                                 showing unit/job/manager information,
125                                 show all properties regardless whether
126                                 they are set or not.</para></listitem>
127                         </varlistentry>
128
129                         <varlistentry>
130                                 <term><option>--full</option></term>
131
132                                 <listitem><para>Do not ellipsize unit
133                                 names and truncate unit descriptions
134                                 in the output of
135                                 <command>list-units</command> and
136                                 <command>list-jobs</command>.</para></listitem>
137                         </varlistentry>
138
139                         <varlistentry>
140                                 <term><option>--fail</option></term>
141
142                                 <listitem><para>If the requested
143                                 operation conflicts with a pending
144                                 unfinished job, fail the command. If
145                                 this is not specified the requested
146                                 operation will replace the pending job,
147                                 if necessary.</para></listitem>
148                         </varlistentry>
149
150                         <varlistentry>
151                                 <term><option>--quiet</option></term>
152                                 <term><option>-q</option></term>
153
154                                 <listitem><para>Suppress output to
155                                 STDOUT in
156                                 <command>snapshot</command>,
157                                 <command>check</command>,
158                                 <command>enable</command> and
159                                 <command>disable</command>.</para></listitem>
160                         </varlistentry>
161
162                         <varlistentry>
163                                 <term><option>--no-block</option></term>
164
165                                 <listitem><para>Do not synchronously wait for
166                                 the requested operation to finish. If this is
167                                 not specified the job will be verified,
168                                 enqueued and <command>systemctl</command> will
169                                 wait until it is completed. By passing this
170                                 argument it is only verified and
171                                 enqueued.</para></listitem> </varlistentry>
172
173                         <varlistentry>
174                                 <term><option>--system</option></term>
175
176                                 <listitem><para>Talk to the systemd
177                                 system manager. (Default)</para></listitem>
178                         </varlistentry>
179
180                         <varlistentry>
181                                 <term><option>--session</option></term>
182
183                                 <listitem><para>Talk to the systemd
184                                 session manager of the calling user.</para></listitem>
185                         </varlistentry>
186
187                         <varlistentry>
188                                 <term><option>--order</option></term>
189                                 <term><option>--require</option></term>
190
191                                 <listitem><para>When used in
192                                 conjunction with the
193                                 <command>dot</command> command (see
194                                 below), selects which dependencies are
195                                 shown in the dependency graph. If
196                                 <option>--order</option> is passed
197                                 only dependencies of type
198                                 <varname>After=</varname> or
199                                 <varname>Before=</varname> are
200                                 shown. If <option>--require</option>
201                                 is passed only dependencies of type
202                                 <varname>Requires=</varname>,
203                                 <varname>RequiresOverridable=</varname>,
204                                 <varname>Requisite=</varname>,
205                                 <varname>RequisiteOverridable=</varname>,
206                                 <varname>Wants=</varname> and
207                                 <varname>Conflicts=</varname> are
208                                 shown. If neither is passed, shows
209                                 dependencies of all these
210                                 types.</para></listitem>
211                         </varlistentry>
212
213                         <varlistentry>
214                                 <term><option>--no-wall</option></term>
215
216                                 <listitem><para>Don't send wall
217                                 message before
218                                 halt, power-off, reboot.</para></listitem>
219                         </varlistentry>
220
221                         <varlistentry>
222                                 <term><option>--global</option></term>
223
224                                 <listitem><para>When used with
225                                 <command>enable</command> and
226                                 <command>disable</command>, operate on the
227                                 global session configuĊ•ation
228                                 directory, thus enabling or disabling
229                                 a unit file globally for all future
230                                 sessions of all users.</para></listitem>
231                         </varlistentry>
232
233                         <varlistentry>
234                                 <term><option>--no-reload</option></term>
235
236                                 <listitem><para>When used with
237                                 <command>enable</command> and
238                                 <command>disable</command>, do not
239                                 implicitly reload daemon configuration
240                                 after executing the
241                                 changes.</para></listitem>
242                         </varlistentry>
243
244                         <varlistentry>
245                                 <term><option>--kill-mode=</option></term>
246
247                                 <listitem><para>When used with
248                                 <command>kill</command>, choose the
249                                 mode how to kill the selected
250                                 processes. Must be one of
251                                 <option>control-group</option>,
252                                 <option>process-group</option> or
253                                 <option>process</option> to select
254                                 whether to kill the entire control
255                                 group, the process group or only the
256                                 selected process itself. If ommitted
257                                 defaults to
258                                 <option>control-group</option> if
259                                 <option>--kill-who=all</option> is
260                                 set, or <option>process</option>
261                                 otherwise. You probably never need to
262                                 use this switch.</para></listitem>
263                         </varlistentry>
264
265                         <varlistentry>
266                                 <term><option>--kill-who=</option></term>
267
268                                 <listitem><para>When used with
269                                 <command>kill</command>, choose which
270                                 processes to kill. Must be one of
271                                 <option>main</option>,
272                                 <option>control</option> or
273                                 <option>all</option> to select whether
274                                 to kill only the main process of the
275                                 unit, the control process or all
276                                 processes of the unit. If ommitted
277                                 defaults to
278                                 <option>all</option>.</para></listitem>
279                         </varlistentry>
280
281                         <varlistentry>
282                                 <term><option>---signal=</option></term>
283                                 <term><option>-s</option></term>
284
285                                 <listitem><para>When used with
286                                 <command>kill</command>, choose which
287                                 signal to send to selected
288                                 processes. Must be one of the well
289                                 know signal specifiers such as
290                                 SIGTERM, SIGINT or SIGSTOP. If
291                                 ommitted defaults to
292                                 <option>SIGTERM</option>.</para></listitem>
293                         </varlistentry>
294
295                         <varlistentry>
296                                 <term><option>--force</option></term>
297                                 <term><option>-f</option></term>
298
299                                 <listitem><para>When used with
300                                 <command>enable</command>, override any
301                                 existing conflicting
302                                 symlinks.</para></listitem>
303
304                                 <listitem><para>When used with
305                                 <command>halt</command>,
306                                 <command>poweroff</command>,
307                                 <command>reboot</command> or
308                                 <command>kexec</command> execute
309                                 selected operation without shutting
310                                 down all units. However, all processes
311                                 will be killed forcibly and all file
312                                 systems are unmounted or remounted
313                                 read-only. This is hence a drastic but
314                                 relatively safe option to request an
315                                 immediate reboot.</para></listitem>
316                         </varlistentry>
317
318                         <varlistentry>
319                                 <term><option>--defaults</option></term>
320
321                                 <listitem><para>When used with
322                                 <command>disable</command>, ensures
323                                 that only the symlinks created by
324                                 <command>enable</command> are removed,
325                                 not all symlinks pointing to the unit
326                                 file that shall be
327                                 disabled.</para></listitem>
328                         </varlistentry>
329                 </variablelist>
330
331                 <para>The following commands are understood:</para>
332
333                 <variablelist>
334                         <varlistentry>
335                                 <term><command>list-units</command></term>
336
337                                 <listitem><para>List known units.</para></listitem>
338                         </varlistentry>
339                         <varlistentry>
340                                 <term><command>start [NAME...]</command></term>
341
342                                 <listitem><para>Start (activate) one
343                                 or more units specified on the command
344                                 line.</para></listitem>
345                         </varlistentry>
346                         <varlistentry>
347                                 <term><command>stop [NAME...]</command></term>
348
349                                 <listitem><para>Stop (deactivate) one
350                                 or more units specified on the command
351                                 line.</para></listitem>
352                         </varlistentry>
353                         <varlistentry>
354                                 <term><command>reload [NAME...]</command></term>
355
356                                 <listitem><para>Asks all units listed
357                                 on the command line to reload their
358                                 configuration. Note that this will
359                                 reload the service-specific
360                                 configuration, not the unit
361                                 configuration file of systemd. If you
362                                 want systemd to reload the
363                                 configuration file of a unit use the
364                                 <command>daemon-reload</command>
365                                 command. In other words: for the
366                                 example case of Apache, this will
367                                 reload Apache's
368                                 <filename>httpd.conf</filename> in the
369                                 web server, not the
370                                 <filename>apache.service</filename>
371                                 systemd unit file. </para>
372
373                                 <para>This command should not be
374                                 confused with the
375                                 <command>daemon-reload</command> or
376                                 <command>load</command>
377                                 commands.</para></listitem>
378
379                         </varlistentry>
380                         <varlistentry>
381                                 <term><command>restart [NAME...]</command></term>
382
383                                 <listitem><para>Restart one or more
384                                 units specified on the command
385                                 line. If the units are not running yet
386                                 they will be
387                                 started.</para></listitem>
388                         </varlistentry>
389                         <varlistentry>
390                                 <term><command>try-restart [NAME...]</command></term>
391
392                                 <listitem><para>Restart one or more
393                                 units specified on the command
394                                 line. If the units are not running yet
395                                 the operation will
396                                 fail.</para></listitem>
397                         </varlistentry>
398                         <varlistentry>
399                                 <term><command>reload-or-restart [NAME...]</command></term>
400                                 <term><command>reload-or-try-restart [NAME...]</command></term>
401
402                                 <listitem><para>Reload one or more
403                                 units if they support it. If not,
404                                 restart them instead. Note that for
405                                 compatibility with SysV and Red Hat
406                                 init scripts
407                                 <command>force-reload</command> and
408                                 <command>condrestart</command> may be
409                                 used as equivalent commands to
410                                 <command>reload-or-try-restart</command>.</para></listitem>
411                         </varlistentry>
412                         <varlistentry>
413                                 <term><command>isolate [NAME]</command></term>
414
415                                 <listitem><para>Start the unit
416                                 specified on the command line and its
417                                 dependencies and stop all others.</para>
418
419                                 <para>This is similar to changing the
420                                 runlevel in a traditional init system. The
421                                 <command>isolate</command> command will
422                                 immediately stop processes that are not
423                                 enabled in the new unit, possibly including
424                                 the graphical environment or terminal you
425                                 are currently using.</para>
426
427                                 <para>Note that this works only on units
428                                 where <option>AllowIsolate=</option> is
429                                 enabled. See
430                                 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
431                                 for details.</para></listitem>
432                         </varlistentry>
433                         <varlistentry>
434                                 <term><command>kill [NAME...]</command></term>
435
436                                 <listitem><para>Send a signal to one
437                                 or more processes of the unit. Use
438                                 <option>--kill-who=</option> to select
439                                 which process to kill. Use
440                                 <option>--kill-mode=</option> to
441                                 select the kill mode and
442                                 <option>--signal=</option> to select
443                                 the signal to send.</para></listitem>
444                         </varlistentry>
445                         <varlistentry>
446                                 <term><command>is-active [NAME...]</command></term>
447
448                                 <listitem><para>Check whether any of
449                                 the specified units is active
450                                 (i.e. running). Returns an exit code
451                                 0 if at least one is active, non-zero
452                                 otherwise. Unless
453                                 <option>--quiet</option> is specified
454                                 this will also print the current unit
455                                 state to STDOUT.</para></listitem>
456                         </varlistentry>
457                         <varlistentry>
458                                 <term><command>status [NAME...|PID...]</command></term>
459
460                                 <listitem><para>Show terse runtime
461                                 status information about one or more
462                                 units. This function is intended to
463                                 generate human-readable output. If you
464                                 are looking for computer-parsable
465                                 output, use <command>show</command>
466                                 instead. If a PID is passed
467                                 information about the unit the process
468                                 of the PID belongs to is
469                                 shown.</para></listitem>
470                         </varlistentry>
471                         <varlistentry>
472                                 <term><command>show [NAME...|JOB...]</command></term>
473
474                                 <listitem><para>Show properties of one
475                                 or more units, jobs or the manager
476                                 itself. If no argument is specified
477                                 properties of the manager will be
478                                 shown. If a unit name is specified
479                                 properties of the unit is shown, and
480                                 if a job id is specified properties of
481                                 the job is shown. By default, empty
482                                 properties are suppressed. Use
483                                 <option>--all</option> to show those
484                                 too. To select specific properties to
485                                 show use
486                                 <option>--property=</option>. This
487                                 command is intended to be used
488                                 whenever computer-parsable output is
489                                 required. Use
490                                 <command>status</command> if you are
491                                 looking for formatted human-readable
492                                 output.</para></listitem>
493                         </varlistentry>
494
495                         <varlistentry>
496                                 <term><command>reset-failed [NAME...]</command></term>
497
498                                 <listitem><para>Reset the
499                                 '<literal>failed</literal>' state of the
500                                 specified units, or if no unit name is
501                                 passed of all units. When a unit fails
502                                 in some way (i.e. process exiting with
503                                 non-zero error code, terminating
504                                 abnormally or timing out) it will
505                                 automatically enter the
506                                 '<literal>failed</literal>' state and
507                                 its exit code and status is recorded
508                                 for introspection by the administrator
509                                 until the service is restarted or
510                                 reset with this
511                                 command.</para></listitem>
512                         </varlistentry>
513
514                         <varlistentry>
515                                 <term><command>enable [NAME...]</command></term>
516
517                                 <listitem><para>Enable one or more
518                                 unit files, as specified on the
519                                 command line. This will create a
520                                 number of symlinks as encoded in the
521                                 <literal>[Install]</literal> sections
522                                 of the unit files. After the symlinks
523                                 have been created the systemd
524                                 configuration is reloaded (in a way
525                                 that is equivalent to
526                                 <command>daemon-reload</command>) to
527                                 ensure the changes are taken into
528                                 account immediately. Note that this
529                                 does not have the effect that any of
530                                 the units enabled are also started at
531                                 the same time. If this is desired a
532                                 separate <command>start</command>
533                                 command must be invoked for the
534                                 unit.</para>
535
536                                 <para>This command will
537                                 print the actions executed. This
538                                 output may be suppressed by passing
539                                 <option>--quiet</option>.</para>
540
541                                 <para>Note that this operation creates
542                                 only the suggested symlinks for the
543                                 units. While this command is the
544                                 recommended way to manipulate the unit
545                                 configuration directory, the
546                                 administrator is free to make
547                                 additional changes manually, by
548                                 placing or removing symlinks in the
549                                 directory. This is particular useful
550                                 to create configurations that deviate
551                                 from the suggested default
552                                 installation. In this case the
553                                 administrator must make sure to invoke
554                                 <command>daemon-reload</command>
555                                 manually as necessary, to ensure his
556                                 changes are taken into account.</para>
557
558                                 <para>Enabling units should not be
559                                 confused with starting (activating)
560                                 units, as done by the
561                                 <command>start</command>
562                                 command. Enabling and starting units
563                                 is orthogonal: units may be enabled
564                                 without being started and started
565                                 without being enabled. Enabling simply
566                                 hooks the unit into various suggested
567                                 places (for example, so that the unit
568                                 is automatically started on boot or
569                                 when a particular kind of hardware is
570                                 plugged in). Starting actually spawns
571                                 the daemon process (in case of service
572                                 units), or binds the socket (in case
573                                 of socket units), and so
574                                 on.</para>
575
576                                 <para>Depending on whether
577                                 <option>--system</option>,
578                                 <option>--session</option> or
579                                 <option>--global</option> is specified
580                                 this enables the unit for the system,
581                                 for sessions of the calling user only
582                                 or for all future session of all
583                                 users. Note that in the latter case no
584                                 systemd daemon configuration is
585                                 reloaded.</para>
586                                 </listitem>
587                         </varlistentry>
588
589                         <varlistentry>
590                                 <term><command>disable [NAME...]</command></term>
591
592                                 <listitem><para>Disables one or more
593                                 units. This removes all symlinks to
594                                 the specified unit files from the unit
595                                 configuration directory, and hence
596                                 undoes the changes made by
597                                 <command>enable</command>. Note
598                                 however that this by default removes
599                                 all symlinks to the unit files
600                                 (i.e. including manual additions), not
601                                 just those actually created by
602                                 <command>enable</command>. If only the
603                                 symlinks that are suggested by default
604                                 shall be removed, pass
605                                 <option>--defaults</option>. This
606                                 implicitly reloads the systemd daemon
607                                 configuration after completing the
608                                 disabling of the units. Note that this
609                                 command does not implicitly stop the
610                                 units that is being disabled. If this
611                                 is desired an additional
612                                 <command>stop</command>command should
613                                 be executed afterwards.</para>
614
615                                 <para>This command will print the
616                                 actions executed. This output may be
617                                 suppressed by passing
618                                 <option>--quiet</option>.</para>
619                                 </listitem>
620
621                                 <para>This command honours
622                                 <option>--system</option>,
623                                 <option>--session</option>,
624                                 <option>--global</option> in a similar
625                                 way as
626                                 <command>enable</command>.</para>
627                         </varlistentry>
628
629                         <varlistentry>
630                                 <term><command>is-enabled [NAME...]</command></term>
631
632                                 <listitem><para>Checks whether any of
633                                 the specified unit files is enabled
634                                 (as with
635                                 <command>enable</command>). Returns an
636                                 exit code of 0 if at least one is
637                                 enabled, non-zero
638                                 otherwise.</para></listitem>
639                         </varlistentry>
640
641                         <varlistentry>
642                                 <term><command>load [NAME...]</command></term>
643
644                                 <listitem><para>Load one or more units
645                                 specified on the command line. This
646                                 will simply load their configuration
647                                 from disk, but not start them. To
648                                 start them you need to use the
649                                 <command>start</command> command which
650                                 will implicitly load a unit that has
651                                 not been loaded yet. Note that systemd
652                                 garbage collects loaded units that are
653                                 not active or referenced by an active
654                                 unit. This means that units loaded
655                                 this way will usually not stay loaded
656                                 for long. Also note that this command
657                                 cannot be used to reload unit
658                                 configuration. Use the
659                                 <command>daemon-reload</command>
660                                 command for that. All in all, this
661                                 command is of little use except for
662                                 debugging.</para>
663                                 <para>This command should not be
664                                 confused with the
665                                 <command>daemon-reload</command> or
666                                 <command>reload</command>
667                                 commands.</para></listitem>
668                         </varlistentry>
669                         <varlistentry>
670                                 <term><command>list-jobs</command></term>
671
672                                 <listitem><para>List jobs that are in progress.</para></listitem>
673                         </varlistentry>
674                         <varlistentry>
675                                 <term><command>cancel [JOB...]</command></term>
676
677                                 <listitem><para>Cancel one or more
678                                 jobs specified on the command line by
679                                 their numeric job
680                                 IDs. If not job id is specified cancels all jobs that are pending.</para></listitem>
681                         </varlistentry>
682                         <varlistentry>
683                                 <term><command>monitor</command></term>
684
685                                 <listitem><para>Monitor unit/job
686                                 changes. This is mostly useful for
687                                 debugging purposes and prints a line
688                                 each time systemd loads or unloads a
689                                 unit configuration file, or a unit
690                                 property changes.</para></listitem>
691                         </varlistentry>
692                         <varlistentry>
693                                 <term><command>dump</command></term>
694
695                                 <listitem><para>Dump server
696                                 status. This will output a (usually
697                                 very long) human readable manager
698                                 status dump. Its format is subject to
699                                 change without notice and should not
700                                 be parsed by
701                                 applications.</para></listitem>
702                         </varlistentry>
703                         <varlistentry>
704                                 <term><command>dot</command></term>
705
706                                 <listitem><para>Generate textual
707                                 dependency graph description in dot
708                                 format for further processing with the
709                                 GraphViz
710                                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
711                                 tool. Use a command line like
712                                 <command>systemctl dot | dot -Tsvg >
713                                 systemd.svg</command> to generate a
714                                 graphical dependency tree. Unless
715                                 <option>--order</option> or
716                                 <option>--require</option> is passed
717                                 the generated graph will show both
718                                 ordering and requirement
719                                 dependencies.</para></listitem>
720                         </varlistentry>
721                         <varlistentry>
722                                 <term><command>snapshot [NAME]</command></term>
723
724                                 <listitem><para>Create a snapshot. If
725                                 a snapshot name is specified, the new
726                                 snapshot will be named after it. If
727                                 none is specified an automatic
728                                 snapshot name is generated. In either
729                                 case, the snapshot name used is
730                                 printed to STDOUT, unless
731                                 <option>--quiet</option> is
732                                 specified.</para>
733
734                                 <para>A snapshot refers to a saved
735                                 state of the systemd manager. It is
736                                 implemented itself as unit that is
737                                 generated dynamically with this
738                                 command and has dependencies on all
739                                 units active at the time. At a later
740                                 time the user may return to this state
741                                 by using the
742                                 <command>isolate</command> command on
743                                 the snapshot unit.</para></listitem>
744
745                                 <para>Snapshots are only useful for
746                                 saving and restoring which units are
747                                 running or are stopped, they do not
748                                 save/restore any other
749                                 state. Snapshots are dynamic and lost
750                                 on reboot.</para>
751                         </varlistentry>
752                         <varlistentry>
753                                 <term><command>delete [NAME...]</command></term>
754
755                                 <listitem><para>Remove a snapshot
756                                 previously created with
757                                 <command>snapshot</command>.</para></listitem>
758                         </varlistentry>
759                         <varlistentry>
760                                 <term><command>daemon-reload</command></term>
761
762                                 <listitem><para>Reload systemd manager
763                                 configuration. This will reload all
764                                 unit files and recreate the entire
765                                 dependency tree. While the daemon is
766                                 reloaded, all sockets systemd listens
767                                 on on behalf of user configuration will
768                                 stay accessible.</para> <para>This
769                                 command should not be confused with
770                                 the <command>load</command> or
771                                 <command>reload</command>
772                                 commands.</para></listitem>
773                         </varlistentry>
774                         <varlistentry>
775                                 <term><command>daemon-reexec</command></term>
776
777                                 <listitem><para>Reexecute the systemd
778                                 manager. This will serialize the
779                                 manager state, reexecute the process
780                                 and deserialize the state again. This
781                                 command is of little use except for
782                                 debugging and package
783                                 upgrades. Sometimes it might be
784                                 helpful as a heavy-weight
785                                 <command>daemon-reload</command>. While
786                                 the daemon is reexecuted all sockets
787                                 systemd listens on on behalf of user
788                                 configuration will stay
789                                 accessible.</para></listitem>
790                         </varlistentry>
791                         <varlistentry>
792                                 <term><command>show-environment</command></term>
793
794                                 <listitem><para>Dump the systemd
795                                 manager environment block. The
796                                 environment block will be dumped in
797                                 straight-forward form suitable for
798                                 sourcing into a shell script. This
799                                 environment block will be passed to
800                                 all processes the manager
801                                 spawns.</para></listitem>
802                         </varlistentry>
803                         <varlistentry>
804                                 <term><command>set-environment [NAME=VALUE...]</command></term>
805
806                                 <listitem><para>Set one or more
807                                 systemd manager environment variables,
808                                 as specified on the command
809                                 line.</para></listitem>
810                         </varlistentry>
811                         <varlistentry>
812                                 <term><command>unset-environment [NAME...]</command></term>
813
814                                 <listitem><para>Unset one or more
815                                 systemd manager environment
816                                 variables. If only a variable name is
817                                 specified it will be removed
818                                 regardless of its value. If a variable
819                                 and a value are specified the variable
820                                 is only removed if it has the
821                                 specified value.</para></listitem>
822                         </varlistentry>
823                         <varlistentry>
824                                 <term><command>default</command></term>
825
826                                 <listitem><para>Enter default
827                                 mode. This is mostly equivalent to
828                                 <command>start
829                                 default.target</command>.</para></listitem>
830                         </varlistentry>
831                         <varlistentry>
832                                 <term><command>rescue</command></term>
833
834                                 <listitem><para>Enter rescue
835                                 mode. This is mostly equivalent to
836                                 <command>isolate
837                                 rescue.target</command> but also
838                                 prints a wall message to all
839                                 users.</para></listitem>
840                         </varlistentry>
841                         <varlistentry>
842                                 <term><command>emergency</command></term>
843
844                                 <listitem><para>Enter emergency
845                                 mode. This is mostly equivalent to
846                                 <command>isolate
847                                 emergency.target</command> but also
848                                 prints a wall message to all
849                                 users.</para></listitem>
850                         </varlistentry>
851                         <varlistentry>
852                                 <term><command>halt</command></term>
853
854                                 <listitem><para>Shut down and halt the
855                                 system. This is mostly equivalent to
856                                 <command>start halt.target</command>
857                                 but also prints a wall message to all
858                                 users.  If
859                                 combined with <option>--force</option>
860                                 shutdown of all running services is
861                                 skipped, however all processes killed
862                                 and all file systems unmounted or
863                                 mounted read-only, immediately
864                                 followed by the
865                                 system halt.</para></listitem>
866                         </varlistentry>
867                         <varlistentry>
868                                 <term><command>poweroff</command></term>
869
870                                 <listitem><para>Shut down and
871                                 power-off the system. This is mostly
872                                 equivalent to <command>start
873                                 poweroff.target</command> but also
874                                 prints a wall message to all
875                                 users. If
876                                 combined with <option>--force</option>
877                                 shutdown of all running services is
878                                 skipped, however all processes killed
879                                 and all file systems unmounted or
880                                 mounted read-only, immediately
881                                 followed by the
882                                 powering off.</para></listitem>
883                         </varlistentry>
884                         <varlistentry>
885                                 <term><command>reboot</command></term>
886
887                                 <listitem><para>Shut down and
888                                 reboot the system. This is mostly
889                                 equivalent to <command>start
890                                 reboot.target</command> but also
891                                 prints a wall message to all
892                                 users. If
893                                 combined with <option>--force</option>
894                                 shutdown of all running services is
895                                 skipped, however all processes killed
896                                 and all file systems unmounted or
897                                 mounted read-only, immediately
898                                 followed by the
899                                 reboot.</para></listitem>
900                         </varlistentry>
901                         <varlistentry>
902                                 <term><command>kexec</command></term>
903
904                                 <listitem><para>Shut down and reboot
905                                 the system via kexec. This is mostly
906                                 equivalent to <command>start
907                                 kexec.target</command> but also prints
908                                 a wall message to all users. If
909                                 combined with <option>--force</option>
910                                 shutdown of all running services is
911                                 skipped, however all processes killed
912                                 and all file systems unmounted or
913                                 mounted read-only, immediately
914                                 followed by the
915                                 reboot.</para></listitem>
916                         </varlistentry>
917                         <varlistentry>
918                                 <term><command>exit</command></term>
919
920                                 <listitem><para>Ask the systemd
921                                 manager to quit. This is only
922                                 supported for session managers
923                                 (i.e. in conjunction with the
924                                 <option>--session</option> option) and
925                                 will fail otherwise.</para></listitem>
926                         </varlistentry>
927                 </variablelist>
928
929         </refsect1>
930
931         <refsect1>
932                 <title>Exit status</title>
933
934                 <para>On success 0 is returned, a non-zero failure
935                 code otherwise.</para>
936         </refsect1>
937
938         <refsect1>
939                 <title>See Also</title>
940                 <para>
941                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
942                         <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
943                         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
944                         <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
945                         <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>
946                 </para>
947         </refsect1>
948
949 </refentry>