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">
6 This file is part of systemd.
8 Copyright 2010 Lennart Poettering
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.
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.
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/>.
24 <refentry id="systemctl">
27 <title>systemctl</title>
28 <productname>systemd</productname>
32 <contrib>Developer</contrib>
33 <firstname>Lennart</firstname>
34 <surname>Poettering</surname>
35 <email>lennart@poettering.net</email>
41 <refentrytitle>systemctl</refentrytitle>
42 <manvolnum>1</manvolnum>
46 <refname>systemctl</refname>
47 <refpurpose>Control the systemd system and service manager</refpurpose>
52 <command>systemctl</command>
53 <arg choice="opt" rep="repeat">OPTIONS</arg>
54 <arg choice="plain">COMMAND</arg>
55 <arg choice="opt" rep="repeat">NAME</arg>
60 <title>Description</title>
62 <para><command>systemctl</command> may be used to
63 introspect and control the state of the
64 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
65 system and service manager.</para>
69 <title>Options</title>
71 <para>The following options are understood:</para>
75 <term><option>-h</option></term>
76 <term><option>--help</option></term>
78 <listitem><para>Prints a short help
79 text and exits.</para></listitem>
83 <term><option>--version</option></term>
86 <para>Prints a short version string and exits.</para>
91 <term><option>-t</option></term>
92 <term><option>--type=</option></term>
95 <para>The argument should be a comma-separated list of unit
96 types such as <option>service</option> and
97 <option>socket</option>.
100 <para>If one of the arguments is a unit type, when listing
101 units, limit display to certain unit types. Otherwise, units
102 of all types will be shown.</para>
104 <para>As a special case, if one of the arguments is
105 <option>help</option>, a list of allowed values will be
106 printed and the program will exit.</para>
111 <term><option>--state=</option></term>
114 <para>The argument should be a comma-separated list of unit LOAD
115 or SUB or ACTIVE states. When listing units, show only those
116 with specified LOAD or SUB or ACTIVE state.</para>
121 <term><option>-p</option></term>
122 <term><option>--property=</option></term>
125 <para>When showing unit/job/manager properties with the
126 <command>show</command> command, limit display to certain
127 properties as specified as argument. If not specified, all
128 set properties are shown. The argument should be a
129 comma-separated list of property names, such as
130 <literal>MainPID</literal>. If specified more than once, all
131 properties with the specified names are shown.</para>
136 <term><option>-a</option></term>
137 <term><option>--all</option></term>
140 <para>When listing units, show all loaded units, regardless
141 of their state, including inactive units. When showing
142 unit/job/manager properties, show all properties regardless
143 whether they are set or not.</para>
144 <para>To list all units installed on the system, use the
145 <command>list-unit-files</command> command instead.</para>
150 <term><option>--reverse</option></term>
153 <para>Show reverse dependencies between units with
154 <command>list-dependencies</command>, i.e. units with
155 dependencies of type <varname>Wants=</varname> or
156 <varname>Requires=</varname> on the given unit.
162 <term><option>--after</option></term>
163 <term><option>--before</option></term>
166 <para>Show which units are started after or before
167 with <command>list-dependencies</command>, respectively.
173 <term><option>-l</option></term>
174 <term><option>--full</option></term>
177 <para>Do not ellipsize unit names, cgroup members, and
178 truncate unit descriptions in the output of
179 <command>list-units</command> and
180 <command>list-jobs</command>.</para>
185 <term><option>--fail</option></term>
188 <para>If the requested operation conflicts with a pending
189 unfinished job, fail the command. If this is not specified,
190 the requested operation will replace the pending job, if
191 necessary. Do not confuse with
192 <option>--failed</option>.</para>
197 <term><option>--show-types</option></term>
200 <para>When showing sockets, show the type of the socket.</para>
205 <term><option>--irreversible</option></term>
208 <para>Mark this transaction's jobs as irreversible. This prevents
209 future conflicting transactions from replacing these jobs.
210 The jobs can still be cancelled using the <command>cancel</command>
216 <term><option>--ignore-dependencies</option></term>
219 <para>When enqueuing a new job, ignore all its dependencies
220 and execute it immediately. If passed, no required units of
221 the unit passed will be pulled in, and no ordering
222 dependencies will be honored. This is mostly a debugging and
223 rescue tool for the administrator and should not be used by
229 <term><option>-i</option></term>
230 <term><option>--ignore-inhibitors</option></term>
233 <para>When system shutdown or a sleep state is requested,
234 ignore inhibitor locks. Applications can establish inhibitor
235 locks to avoid that certain important operations (such as CD
236 burning or suchlike) are interrupted by system shutdown or a
237 sleep state. Any user may take these locks and privileged
238 users may override these locks. If any locks are taken,
239 shutdown and sleep state requests will normally fail
240 (regardless if privileged or not) and a list of active locks
241 is printed. However, if <option>--ignore-inhibitors</option>
242 is specified, the locks are ignored and not printed, and the
243 operation attempted anyway, possibly requiring additional
249 <term><option>-q</option></term>
250 <term><option>--quiet</option></term>
253 <para>Suppress output to standard output in
254 <command>snapshot</command>,
255 <command>is-active</command>,
256 <command>is-failed</command>,
257 <command>enable</command> and
258 <command>disable</command>.</para>
263 <term><option>--no-block</option></term>
266 <para>Do not synchronously wait for the requested operation
267 to finish. If this is not specified, the job will be
268 verified, enqueued and <command>systemctl</command> will
269 wait until it is completed. By passing this argument, it is
270 only verified and enqueued.</para>
275 <term><option>--no-legend</option></term>
278 <para>Do not print a legend, i.e. the column headers and
279 the footer with hints.</para>
284 <term><option>--no-pager</option></term>
287 <para>Do not pipe output into a pager.</para>
292 <term><option>--system</option></term>
295 <para>Talk to the systemd system manager. (Default)</para>
300 <term><option>--user</option></term>
303 <para>Talk to the systemd manager of the calling
309 <term><option>--no-wall</option></term>
312 <para>Do not send wall message before halt, power-off,
318 <term><option>--global</option></term>
321 <para>When used with <command>enable</command> and
322 <command>disable</command>, operate on the global user
323 configuration directory, thus enabling or disabling a unit
324 file globally for all future logins of all users.</para>
329 <term><option>--no-reload</option></term>
332 <para>When used with <command>enable</command> and
333 <command>disable</command>, do not implicitly reload daemon
334 configuration after executing the changes.</para>
339 <term><option>--no-ask-password</option></term>
342 <para>When used with <command>start</command> and related
343 commands, disables asking for passwords. Background services
344 may require input of a password or passphrase string, for
345 example to unlock system hard disks or cryptographic
346 certificates. Unless this option is specified and the
347 command is invoked from a terminal,
348 <command>systemctl</command> will query the user on the
349 terminal for the necessary secrets. Use this option to
350 switch this behavior off. In this case, the password must be
351 supplied by some other means (for example graphical password
352 agents) or the service might fail. This also disables
353 querying the user for authentication for privileged
360 <term><option>--kill-who=</option></term>
363 <para>When used with <command>kill</command>, choose which
364 processes to kill. Must be one of <option>main</option>,
365 <option>control</option> or <option>all</option> to select
366 whether to kill only the main process of the unit, the
367 control process or all processes of the unit. If omitted,
368 defaults to <option>all</option>.</para>
374 <term><option>-s</option></term>
375 <term><option>--signal=</option></term>
378 <para>When used with <command>kill</command>, choose which
379 signal to send to selected processes. Must be one of the
380 well known signal specifiers such as <constant>SIGTERM</constant>, <constant>SIGINT</constant> or
381 <constant>SIGSTOP</constant>. If omitted, defaults to
382 <option>SIGTERM</option>.</para>
387 <term><option>-f</option></term>
388 <term><option>--force</option></term>
391 <para>When used with <command>enable</command>, overwrite
392 any existing conflicting symlinks.</para>
394 <para>When used with <command>halt</command>,
395 <command>poweroff</command>, <command>reboot</command> or
396 <command>kexec</command>, execute the selected operation
397 without shutting down all units. However, all processes will
398 be killed forcibly and all file systems are unmounted or
399 remounted read-only. This is hence a drastic but relatively
400 safe option to request an immediate reboot. If
401 <option>--force</option> is specified twice for these
402 operations, they will be executed immediately without
403 terminating any processes or umounting any file
404 systems. Warning: specifying <option>--force</option> twice
405 with any of these operations might result in data
411 <term><option>--root=</option></term>
415 <command>enable</command>/<command>disable</command>/<command>is-enabled</command>
416 (and related commands), use alternative root path when
417 looking for unit files.</para>
423 <term><option>--runtime</option></term>
426 <para>When used with <command>enable</command>,
427 <command>disable</command>, <command>is-enabled</command>
428 (and related commands), make changes only temporarily, so
429 that they are lost on the next reboot. This will have the
430 effect that changes are not made in subdirectories of
431 <filename>/etc</filename> but in <filename>/run</filename>,
432 with identical immediate effects, however, since the latter
433 is lost on reboot, the changes are lost too.</para>
435 <para>Similar, when used with
436 <command>set-property</command>, make changes only
437 temporarily, so that they are lost on the next
443 <term><option>-H</option></term>
444 <term><option>--host</option></term>
447 <para>Execute operation remotely. Specify a hostname, or
448 username and hostname separated by <literal>@</literal>, to connect to. This
449 will use SSH to talk to the remote systemd
455 <term><option>-P</option></term>
456 <term><option>--privileged</option></term>
459 <para>Acquire privileges via PolicyKit before executing the
465 <term><option>-n</option></term>
466 <term><option>--lines=</option></term>
469 <para>When used with <command>status</command>, controls the
470 number of journal lines to show, counting from the most
471 recent ones. Takes a positive integer argument. Defaults to
477 <term><option>-o</option></term>
478 <term><option>--output=</option></term>
481 <para>When used with <command>status</command>, controls the
482 formatting of the journal entries that are shown. For the
483 available choices, see
484 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
485 Defaults to <literal>short</literal>.</para>
490 <term><option>--plain</option></term>
493 <para>When used with <command>list-dependencies</command>,
494 the output is printed as a list instead of a tree.</para>
502 <title>Commands</title>
504 <para>The following commands are understood:</para>
508 <term><command>list-units</command></term>
511 <para>List known units (subject to limitations specified
512 with <option>-t</option>).</para>
514 <para>This is the default command.</para>
519 <term><command>list-sockets</command></term>
522 <para>List socket units ordered by the listening address. Produces output
525 LISTEN UNIT ACTIVATES
526 /dev/initctl systemd-initctl.socket systemd-initctl.service
528 [::]:22 sshd.socket sshd.service
529 kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
533 Note: because the addresses might contains spaces, this output
534 is not suitable for programmatic consumption.
537 <para>See also the options <option>--show-types</option>,
538 <option>--all</option>, and <option>--failed</option>.</para>
543 <term><command>start <replaceable>NAME</replaceable>...</command></term>
546 <para>Start (activate) one or more units specified on the
551 <term><command>stop <replaceable>NAME</replaceable>...</command></term>
554 <para>Stop (deactivate) one or more units specified on the
559 <term><command>reload <replaceable>NAME</replaceable>...</command></term>
562 <para>Asks all units listed on the command line to reload
563 their configuration. Note that this will reload the
564 service-specific configuration, not the unit configuration
565 file of systemd. If you want systemd to reload the
566 configuration file of a unit use the
567 <command>daemon-reload</command> command. In other words:
568 for the example case of Apache, this will reload Apache's
569 <filename>httpd.conf</filename> in the web server, not the
570 <filename>apache.service</filename> systemd unit
573 <para>This command should not be confused with the
574 <command>daemon-reload</command> or <command>load</command>
580 <term><command>restart <replaceable>NAME</replaceable>...</command></term>
583 <para>Restart one or more units specified on the command
584 line. If the units are not running yet, they will be
589 <term><command>try-restart <replaceable>NAME</replaceable>...</command></term>
592 <para>Restart one or more units specified on the command
593 line if the units are running. This does nothing if units are not
594 running. Note that, for compatibility with Red Hat init
595 scripts, <command>condrestart</command> is equivalent to this
600 <term><command>reload-or-restart <replaceable>NAME</replaceable>...</command></term>
603 <para>Reload one or more units if they support it. If not,
604 restart them instead. If the units are not running yet, they
605 will be started.</para>
609 <term><command>reload-or-try-restart <replaceable>NAME</replaceable>...</command></term>
612 <para>Reload one or more units if they support it. If not,
613 restart them instead. This does nothing if the units are not
614 running. Note that, for compatibility with SysV init scripts,
615 <command>force-reload</command> is equivalent to this
620 <term><command>isolate <replaceable>NAME</replaceable></command></term>
623 <para>Start the unit specified on the command line and its
624 dependencies and stop all others.</para>
626 <para>This is similar to changing the runlevel in a
627 traditional init system. The <command>isolate</command>
628 command will immediately stop processes that are not enabled
629 in the new unit, possibly including the graphical
630 environment or terminal you are currently using.</para>
632 <para>Note that this is allowed only on units where
633 <option>AllowIsolate=</option> is enabled. See
634 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
639 <term><command>kill <replaceable>NAME</replaceable>...</command></term>
642 <para>Send a signal to one or more processes of the
643 unit. Use <option>--kill-who=</option> to select which
644 process to kill. Use <option>--kill-mode=</option> to select
645 the kill mode and <option>--signal=</option> to select the
646 signal to send.</para>
650 <term><command>is-active <replaceable>NAME</replaceable>...</command></term>
653 <para>Check whether any of the specified units are active
654 (i.e. running). Returns an exit code 0 if at least one is
655 active, non-zero otherwise. Unless <option>--quiet</option>
656 is specified, this will also print the current unit state to
661 <term><command>is-failed <replaceable>NAME</replaceable>...</command></term>
664 <para>Check whether any of the specified units are in a "failed" state.
665 Returns an exit code 0 if at least one has failed, non-zero
666 otherwise. Unless <option>--quiet</option> is specified, this
667 will also print the current unit state to
672 <term><command>status [<replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...]</command></term>
675 <para>Show terse runtime status information about one or
676 more units, followed by most recent log data from the
677 journal. If no units are specified, show all units (subject
678 to limitations specified with <option>-t</option>). If a PID
679 is passed, show information about the unit the process
682 <para>This function is intended to generate human-readable
683 output. If you are looking for computer-parsable output, use
684 <command>show</command> instead.</para>
688 <term><command>show [<replaceable>NAME</replaceable>...|<replaceable>JOB</replaceable>...]</command></term>
691 <para>Show properties of one or more units, jobs, or the
692 manager itself. If no argument is specified properties of
693 the manager will be shown. If a unit name is specified
694 properties of the unit is shown, and if a job id is
695 specified properties of the job is shown. By default, empty
696 properties are suppressed. Use <option>--all</option> to
697 show those too. To select specific properties to show use
698 <option>--property=</option>. This command is intended to be
699 used whenever computer-parsable output is required. Use
700 <command>status</command> if you are looking for formatted
701 human-readable output.</para>
706 <term><command>set-property <replaceable>NAME</replaceable> <replaceable>ASSIGNMENT</replaceable>...</command></term>
709 <para>Set the specified unit properties at runtime where
710 this is supported. This allows changing configuration
711 parameter properties such as resource management controls at
712 runtime. Not all properties may be changed at runtime, but
713 many resource management settings (primarily those in
714 <citerefentry><refentrytitle>systemd.cgroup</refentrytitle><manvolnum>5</manvolnum></citerefentry>)
715 may. The changes are applied instantly, and stored on disk
716 for future boots, unless <option>--runtime</option> is
717 passed, in which case the settings only apply until the next
718 reboot. The syntax of the property assignment follows
719 closely the syntax of assignments in unit files.</para>
721 <para>Example: <command>systemctl set-property foobar.service CPUShares=777</command></para>
723 <para>Note that this command allows changing multiple
724 properties at the same time, which is preferable over
725 setting them individually. Like unit file configuration
726 settings, assigning the empty list to list parameters will
727 reset the list.</para>
732 <term><command>help <replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...</command></term>
735 <para>Show manual pages for one or more units, if
736 available. If a PID is given, the manual pages for the unit
737 the process belongs to are shown.</para>
742 <term><command>reset-failed [<replaceable>NAME</replaceable>...]</command></term>
745 <para>Reset the <literal>failed</literal> state of the
746 specified units, or if no unit name is passed, reset the state of all
747 units. When a unit fails in some way (i.e. process exiting
748 with non-zero error code, terminating abnormally or timing
749 out), it will automatically enter the
750 <literal>failed</literal> state and its exit code and status
751 is recorded for introspection by the administrator until the
752 service is restarted or reset with this command.</para>
757 <term><command>list-unit-files</command></term>
760 <para>List installed unit files.</para>
765 <term><command>enable <replaceable>NAME</replaceable>...</command></term>
768 <para>Enable one or more unit files or unit file instances,
769 as specified on the command line. This will create a number
770 of symlinks as encoded in the <literal>[Install]</literal>
771 sections of the unit files. After the symlinks have been
772 created, the systemd configuration is reloaded (in a way that
773 is equivalent to <command>daemon-reload</command>) to ensure
774 the changes are taken into account immediately. Note that
775 this does <emphasis>not</emphasis> have the effect of also
776 starting any of the units being enabled. If this
777 is desired, a separate <command>start</command> command must
778 be invoked for the unit. Also note that in case of instance
779 enablement, symlinks named the same as instances are created in
780 the install location, however they all point to the same
781 template unit file.</para>
783 <para>This command will print the actions executed. This
784 output may be suppressed by passing <option>--quiet</option>.
787 <para>Note that this operation creates only the suggested
788 symlinks for the units. While this command is the
789 recommended way to manipulate the unit configuration
790 directory, the administrator is free to make additional
791 changes manually by placing or removing symlinks in the
792 directory. This is particularly useful to create
793 configurations that deviate from the suggested default
794 installation. In this case, the administrator must make sure
795 to invoke <command>daemon-reload</command> manually as
796 necessary to ensure the changes are taken into account.
799 <para>Enabling units should not be confused with starting
800 (activating) units, as done by the <command>start</command>
801 command. Enabling and starting units is orthogonal: units
802 may be enabled without being started and started without
803 being enabled. Enabling simply hooks the unit into various
804 suggested places (for example, so that the unit is
805 automatically started on boot or when a particular kind of
806 hardware is plugged in). Starting actually spawns the daemon
807 process (in case of service units), or binds the socket (in
808 case of socket units), and so on.</para>
810 <para>Depending on whether <option>--system</option>,
811 <option>--user</option> or <option>--global</option> is
812 specified, this enables the unit for the system, for the
813 calling user only or for all future logins of all
814 users. Note that in the last case, no systemd daemon
815 configuration is reloaded.</para>
820 <term><command>disable <replaceable>NAME</replaceable>...</command></term>
823 <para>Disables one or more units. This removes all symlinks
824 to the specified unit files from the unit configuration
825 directory, and hence undoes the changes made by
826 <command>enable</command>. Note however that this removes
827 all symlinks to the unit files (i.e. including manual
828 additions), not just those actually created by
829 <command>enable</command>. This call implicitly reloads the
830 systemd daemon configuration after completing the disabling
831 of the units. Note that this command does not implicitly
832 stop the units that are being disabled. If this is desired,
833 an additional <command>stop</command> command should be
834 executed afterwards.</para>
836 <para>This command will print the actions executed. This
837 output may be suppressed by passing <option>--quiet</option>.
840 <para>This command honors <option>--system</option>,
841 <option>--user</option>, <option>--global</option> in a
842 similar way as <command>enable</command>.</para>
847 <term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>
850 <para>Checks whether any of the specified unit files are
851 enabled (as with <command>enable</command>). Returns an exit
852 code of 0 if at least one is enabled, non-zero
853 otherwise. Prints the current enable status. To suppress
854 this output, use <option>--quiet</option>.</para>
859 <term><command>reenable <replaceable>NAME</replaceable>...</command></term>
862 <para>Reenable one or more unit files, as specified on the
863 command line. This is a combination of
864 <command>disable</command> and <command>enable</command> and
865 is useful to reset the symlinks a unit is enabled with to
866 the defaults configured in the <literal>[Install]</literal>
867 section of the unit file.</para>
872 <term><command>preset <replaceable>NAME</replaceable>...</command></term>
875 <para>Reset one or more unit files, as specified on the
876 command line, to the defaults configured in the preset
877 policy files. This has the same effect as
878 <command>disable</command> or <command>enable</command>,
879 depending how the unit is listed in the preset files. For
880 more information on the preset policy format, see
881 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
882 For more information on the concept of presets, please
884 <ulink url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
890 <term><command>mask <replaceable>NAME</replaceable>...</command></term>
893 <para>Mask one or more unit files, as specified on the
894 command line. This will link these units to
895 <filename>/dev/null</filename>, making it impossible to
896 start them. This is a stronger version of
897 <command>disable</command>, since it prohibits all kinds of
898 activation of the unit, including manual activation. Use
899 this option with care.</para>
904 <term><command>unmask <replaceable>NAME</replaceable>...</command></term>
907 <para>Unmask one or more unit files, as specified on the
908 command line. This will undo the effect of
909 <command>mask</command>.</para>
914 <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
917 <para>Link a unit file that is not in the unit file search
918 paths into the unit file search path. This requires an
919 absolute path to a unit file. The effect of this can be
920 undone with <command>disable</command>. The effect of this
921 command is that a unit file is available for
922 <command>start</command> and other commands although it
923 is not installed directly in the unit search path.</para>
928 <term><command>get-default</command></term>
931 <para>Get the default target specified
932 via <filename>default.target</filename> link.</para>
937 <term><command>set-default <replaceable>NAME</replaceable></command></term>
940 <para>Set the default target to boot into. Command links
941 <filename>default.target</filename> to the given unit.</para>
946 <term><command>list-jobs</command></term>
949 <para>List jobs that are in progress.</para>
953 <term><command>cancel <replaceable>JOB</replaceable>...</command></term>
956 <para>Cancel one or more jobs specified on the command line
957 by their numeric job IDs. If no job ID is specified, cancel
958 all pending jobs.</para>
963 <term><command>list-dependencies <replaceable>NAME</replaceable></command></term>
966 <para>Shows required and wanted units of the specified
967 unit. If no unit is specified,
968 <filename>default.target</filename> is implied. Target units
969 are recursively expanded. When <option>--all</option> is
970 passed, all other units are recursively expanded as
975 <term><command>snapshot [<replaceable>NAME</replaceable>]</command></term>
978 <para>Create a snapshot. If a snapshot name is specified,
979 the new snapshot will be named after it. If none is
980 specified, an automatic snapshot name is generated. In either
981 case, the snapshot name used is printed to STDOUT, unless
982 <option>--quiet</option> is specified.</para>
984 <para>A snapshot refers to a saved state of the systemd
985 manager. It is implemented itself as a unit that is
986 generated dynamically with this command and has dependencies
987 on all units active at the time. At a later time, the user
988 may return to this state by using the
989 <command>isolate</command> command on the snapshot unit.
992 <para>Snapshots are only useful for saving and restoring
993 which units are running or are stopped, they do not
994 save/restore any other state. Snapshots are dynamic and lost
999 <term><command>delete <replaceable>NAME</replaceable>...</command></term>
1002 <para>Remove a snapshot previously created with
1003 <command>snapshot</command>.</para>
1007 <term><command>daemon-reload</command></term>
1010 <para>Reload systemd manager configuration. This will reload
1011 all unit files and recreate the entire dependency
1012 tree. While the daemon is reloaded, all sockets systemd
1013 listens on on behalf of user configuration will stay
1014 accessible.</para> <para>This command should not be confused
1015 with the <command>load</command> or
1016 <command>reload</command> commands.</para>
1020 <term><command>daemon-reexec</command></term>
1023 <para>Reexecute the systemd manager. This will serialize the
1024 manager state, reexecute the process and deserialize the
1025 state again. This command is of little use except for
1026 debugging and package upgrades. Sometimes it might be
1027 helpful as a heavy-weight <command>daemon-reload</command>.
1028 While the daemon is reexecuted, all sockets systemd listening
1029 on behalf of user configuration will stay accessible.
1034 <term><command>show-environment</command></term>
1037 <para>Dump the systemd manager environment block. The
1038 environment block will be dumped in straight-forward form
1039 suitable for sourcing into a shell script. This environment
1040 block will be passed to all processes the manager
1045 <term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>
1048 <para>Set one or more systemd manager environment variables,
1049 as specified on the command line.</para>
1053 <term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>
1056 <para>Unset one or more systemd manager environment
1057 variables. If only a variable name is specified, it will be
1058 removed regardless of its value. If a variable and a value
1059 are specified, the variable is only removed if it has the
1060 specified value.</para>
1064 <term><command>default</command></term>
1067 <para>Enter default mode. This is mostly equivalent to
1068 <command>isolate default.target</command>.</para>
1072 <term><command>rescue</command></term>
1075 <para>Enter rescue mode. This is mostly equivalent to
1076 <command>isolate rescue.target</command>, but also prints a
1077 wall message to all users.</para>
1081 <term><command>emergency</command></term>
1084 <para>Enter emergency mode. This is mostly equivalent to
1085 <command>isolate emergency.target</command>, but also prints
1086 a wall message to all users.</para>
1090 <term><command>halt</command></term>
1093 <para>Shut down and halt the system. This is mostly equivalent to
1094 <command>start halt.target --irreversible</command>, but also
1095 prints a wall message to all users. If combined with
1096 <option>--force</option>, shutdown of all running services is
1097 skipped, however all processes are killed and all file
1098 systems are unmounted or mounted read-only, immediately
1099 followed by the system halt. If <option>--force</option> is
1100 specified twice, the operation is immediately executed
1101 without terminating any processes or unmounting any file
1102 systems. This may result in data loss.</para>
1106 <term><command>poweroff</command></term>
1109 <para>Shut down and power-off the system. This is mostly
1110 equivalent to <command>start poweroff.target --irreversible</command>,
1111 but also prints a wall message to all users. If combined with
1112 <option>--force</option>, shutdown of all running services is
1113 skipped, however all processes are killed and all file
1114 systems are unmounted or mounted read-only, immediately
1115 followed by the powering off. If <option>--force</option> is
1116 specified twice, the operation is immediately executed
1117 without terminating any processes or unmounting any file
1118 systems. This may result in data loss.</para>
1122 <term><command>reboot</command></term>
1125 <para>Shut down and reboot the system. This is mostly
1126 equivalent to <command>start reboot.target --irreversible</command>,
1127 but also prints a wall message to all users. If combined with
1128 <option>--force</option>, shutdown of all running services is
1129 skipped, however all processes are killed and all file
1130 systems are unmounted or mounted read-only, immediately
1131 followed by the reboot. If <option>--force</option> is
1132 specified twice, the operation is immediately executed
1133 without terminating any processes or unmounting any file
1134 systems. This may result in data loss.</para>
1138 <term><command>kexec</command></term>
1141 <para>Shut down and reboot the system via kexec. This is
1142 mostly equivalent to <command>start kexec.target --irreversible</command>,
1143 but also prints a wall message to all users. If combined
1144 with <option>--force</option>, shutdown of all running
1145 services is skipped, however all processes are killed and
1146 all file systems are unmounted or mounted read-only,
1147 immediately followed by the reboot.</para>
1151 <term><command>exit</command></term>
1154 <para>Ask the systemd manager to quit. This is only
1155 supported for user service managers (i.e. in conjunction
1156 with the <option>--user</option> option) and will fail
1162 <term><command>suspend</command></term>
1165 <para>Suspend the system. This will trigger activation of
1166 the special <filename>suspend.target</filename> target.
1171 <term><command>hibernate</command></term>
1174 <para>Hibernate the system. This will trigger activation of
1175 the special <filename>hibernate.target</filename> target.
1180 <term><command>hybrid-sleep</command></term>
1183 <para>Hibernate and suspend the system. This will trigger
1184 activation of the special
1185 <filename>hybrid-sleep.target</filename> target.</para>
1189 <term><command>switch-root <replaceable>ROOT</replaceable> [<replaceable>INIT</replaceable>]</command></term>
1192 <para>Switches to a different root directory and executes a
1193 new system manager process below it. This is intended for
1194 usage in initial RAM disks ("initrd"), and will transition
1195 from the initrd's system manager process (a.k.a "init"
1196 process) to the main system manager process. This call takes two
1197 arguments: the directory that is to become the new root directory, and
1198 the path to the new system manager binary below it to
1199 execute as PID 1. If the latter is omitted or the empty
1200 string, a systemd binary will automatically be searched for
1201 and used as init. If the system manager path is omitted or
1202 equal to the empty string, the state of the initrd's system
1203 manager process is passed to the main system manager, which
1204 allows later introspection of the state of the services
1205 involved in the initrd boot.</para>
1213 <title>Exit status</title>
1215 <para>On success, 0 is returned, a non-zero failure
1216 code otherwise.</para>
1220 <title>Environment</title>
1222 <variablelist class='environment-variables'>
1224 <term><varname>$SYSTEMD_PAGER</varname></term>
1227 <para>Pager to use when <option>--no-pager</option> is not
1228 given; overrides <varname>$PAGER</varname>. Setting this to
1229 an empty string or the value <literal>cat</literal> is
1230 equivalent to passing
1231 <option>--no-pager</option>.</para>
1238 <title>See Also</title>
1240 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1241 <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1242 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1243 <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1244 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1245 <citerefentry><refentrytitle>systemd.cgroupq</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1246 <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1247 <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1248 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>