1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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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>, or unit load states such as
98 <option>loaded</option> and <option>masked</option>
99 (types and states can be mixed).</para>
101 <para>If one of the arguments is a unit type, when listing
102 units, limit display to certain unit types. Otherwise units
103 of all types will be shown.</para>
105 <para>If one of the arguments is a unit load state, when
106 listing units, limit display to certain unit
107 types. Otherwise units of in all load states will be
110 <para>As a special case, if one of the arguments is
111 <option>help</option>, a list of allowed values will be
112 printed and the program will exit.</para>
117 <term><option>-p</option></term>
118 <term><option>--property=</option></term>
121 <para>When showing unit/job/manager properties with the
122 <command>show</command> command, limit display to certain
123 properties as specified as argument. If not specified all
124 set properties are shown. The argument should be a
125 comma-separated list of property names, such as
126 <literal>MainPID</literal>. If specified more than once all
127 properties with the specified names are shown.</para>
132 <term><option>-a</option></term>
133 <term><option>--all</option></term>
136 <para>When listing units, show all loaded units, regardless
137 of their state, including inactive units. When showing
138 unit/job/manager properties, show all properties regardless
139 whether they are set or not.</para>
140 <para>To list all units installed on the system, use the
141 <command>list-unit-files</command> command instead.</para>
146 <term><option>--reverse</option></term>
149 <para>Show reverse dependencies between units with
150 <command>list-dependencies</command>, i.e. units with
151 dependencies of type <varname>Wants=</varname> or
152 <varname>Requires=</varname> on the given unit.
158 <term><option>--after</option></term>
159 <term><option>--before</option></term>
162 <para>Show which units are started after, resp. before
163 with <command>list-dependencies</command>.
169 <term><option>--failed</option></term>
172 <para>When listing units, show only failed units. Do not
173 confuse with <option>--fail</option>.</para>
178 <term><option>--full</option></term>
181 <para>Do not ellipsize unit names, cgroup members, and
182 truncate unit descriptions in the output of
183 <command>list-units</command> and
184 <command>list-jobs</command>.</para>
189 <term><option>--fail</option></term>
192 <para>If the requested operation conflicts with a pending
193 unfinished job, fail the command. If this is not specified
194 the requested operation will replace the pending job, if
195 necessary. Do not confuse with
196 <option>--failed</option>.</para>
201 <term><option>--show-types</option></term>
204 <para>When showing sockets, show the type of the socket.</para>
209 <term><option>--irreversible</option></term>
212 <para>Mark this transaction's jobs as irreversible. This prevents
213 future conflicting transactions from replacing these jobs.
214 The jobs can still be cancelled using the <command>cancel</command>
220 <term><option>--ignore-dependencies</option></term>
223 <para>When enqueuing a new job ignore all its dependencies
224 and execute it immediately. If passed no required units of
225 the unit passed will be pulled in, and no ordering
226 dependencies will be honored. This is mostly a debugging and
227 rescue tool for the administrator and should not be used by
233 <term><option>-i</option></term>
234 <term><option>--ignore-inhibitors</option></term>
237 <para>When system shutdown or a sleep state is requested,
238 ignore inhibitor locks. Applications can establish inhibitor
239 locks to avoid that certain important operations (such as CD
240 burning or suchlike) are interrupted by system shutdown or a
241 sleep state. Any user may take these locks and privileged
242 users may override these locks. If any locks are taken,
243 shutdown and sleep state requests will normally fail
244 (regardless if privileged or not) and a list of active locks
245 is printed. However if <option>--ignore-inhibitors</option>
246 is specified the locks are ignored and not printed, and the
247 operation attempted anyway, possibly requiring additional
253 <term><option>-q</option></term>
254 <term><option>--quiet</option></term>
257 <para>Suppress output to standard output in
258 <command>snapshot</command>,
259 <command>is-active</command>,
260 <command>is-failed</command>,
261 <command>enable</command> and
262 <command>disable</command>.</para>
267 <term><option>--no-block</option></term>
270 <para>Do not synchronously wait for the requested operation
271 to finish. If this is not specified the job will be
272 verified, enqueued and <command>systemctl</command> will
273 wait until it is completed. By passing this argument it is
274 only verified and enqueued.</para>
279 <term><option>--no-legend</option></term>
282 <para>Do not print a legend, i.e. the column headers and
283 the footer with hints.</para>
288 <term><option>--no-pager</option></term>
291 <para>Do not pipe output into a pager.</para>
296 <term><option>--system</option></term>
299 <para>Talk to the systemd system manager. (Default)</para>
304 <term><option>--user</option></term>
307 <para>Talk to the systemd manager of the calling
313 <term><option>--no-wall</option></term>
316 <para>Don't send wall message before halt, power-off,
322 <term><option>--global</option></term>
325 <para>When used with <command>enable</command> and
326 <command>disable</command>, operate on the global user
327 configuration directory, thus enabling or disabling a unit
328 file globally for all future logins of all users.</para>
333 <term><option>--no-reload</option></term>
336 <para>When used with <command>enable</command> and
337 <command>disable</command>, do not implicitly reload daemon
338 configuration after executing the changes.</para>
343 <term><option>--no-ask-password</option></term>
346 <para>When used with <command>start</command> and related
347 commands, disables asking for passwords. Background services
348 may require input of a password or passphrase string, for
349 example to unlock system hard disks or cryptographic
350 certificates. Unless this option is specified and the
351 command is invoked from a terminal
352 <command>systemctl</command> will query the user on the
353 terminal for the necessary secrets. Use this option to
354 switch this behavior off. In this case the password must be
355 supplied by some other means (for example graphical password
356 agents) or the service might fail. This also disables
357 querying the user for authentication for privileged
364 <term><option>--kill-who=</option></term>
367 <para>When used with <command>kill</command>, choose which
368 processes to kill. Must be one of <option>main</option>,
369 <option>control</option> or <option>all</option> to select
370 whether to kill only the main process of the unit, the
371 control process or all processes of the unit. If omitted
372 defaults to <option>all</option>.</para>
378 <term><option>-s</option></term>
379 <term><option>--signal=</option></term>
382 <para>When used with <command>kill</command>, choose which
383 signal to send to selected processes. Must be one of the
384 well known signal specifiers such as SIGTERM, SIGINT or
385 SIGSTOP. If omitted defaults to
386 <option>SIGTERM</option>.</para>
391 <term><option>-f</option></term>
392 <term><option>--force</option></term>
395 <para>When used with <command>enable</command>, overwrite
396 any existing conflicting symlinks.</para>
398 <para>When used with <command>halt</command>,
399 <command>poweroff</command>, <command>reboot</command> or
400 <command>kexec</command> execute the selected operation
401 without shutting down all units. However, all processes will
402 be killed forcibly and all file systems are unmounted or
403 remounted read-only. This is hence a drastic but relatively
404 safe option to request an immediate reboot. If
405 <option>--force</option> is specified twice for these
406 operations, they will be executed immediately without
407 terminating any processes or umounting any file
408 systems. Warning: specifying <option>--force</option> twice
409 with any of these operations might result in data
415 <term><option>--root=</option></term>
419 <command>enable</command>/<command>disable</command>/<command>is-enabled</command>
420 (and related commands), use alternative root path when
421 looking for unit files.</para>
427 <term><option>--runtime</option></term>
430 <para>When used with <command>enable</command>,
431 <command>disable</command>, <command>is-enabled</command>
432 (and related commands), make changes only temporarily, so
433 that they are lost on the next reboot. This will have the
434 effect that changes are not made in subdirectories of
435 <filename>/etc</filename> but in <filename>/run</filename>,
436 with identical immediate effects, however, since the latter
437 is lost on reboot, the changes are lost too.</para>
439 <para>Similar, when used with
440 <command>set-cgroup-attr</command>,
441 <command>unset-cgroup-attr</command>,
442 <command>set-cgroup</command> and
443 <command>unset-cgroup</command>, make changes only
444 temporarily, so that they are lost on the next
450 <term><option>-H</option></term>
451 <term><option>--host</option></term>
454 <para>Execute operation remotely. Specify a hostname, or
455 username and hostname separated by @, to connect to. This
456 will use SSH to talk to the remote systemd
462 <term><option>-P</option></term>
463 <term><option>--privileged</option></term>
466 <para>Acquire privileges via PolicyKit before executing the
472 <term><option>-n</option></term>
473 <term><option>--lines=</option></term>
476 <para>When used with <command>status</command> controls the
477 number of journal lines to show, counting from the most
478 recent ones. Takes a positive integer argument. Defaults to
484 <term><option>-o</option></term>
485 <term><option>--output=</option></term>
488 <para>When used with <command>status</command> controls the
489 formatting of the journal entries that are shown. For the
490 available choices see
491 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
492 Defaults to <literal>short</literal>.</para>
497 <term><option>--plain</option></term>
500 <para>When used with <command>list-dependencies</command>
501 the output is printed as a list instead of a tree.</para>
509 <title>Commands</title>
511 <para>The following commands are understood:</para>
515 <term><command>list-units</command></term>
518 <para>List known units (subject to limitations specified
519 with <option>-t</option>).</para>
521 <para>This is the default command.</para>
526 <term><command>list-sockets</command></term>
529 <para>List socket units ordered by the listening address. Produces output
532 LISTEN UNIT ACTIVATES
533 /dev/initctl systemd-initctl.socket systemd-initctl.service
535 [::]:22 sshd.socket sshd.service
536 kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
540 Note: because the addresses might contains spaces, this output
541 is not suitable for programatic consumption.
544 <para>See also the options <option>--show-types</option>,
545 <option>--all</option>, and <option>--failed</option>.</para>
550 <term><command>start <replaceable>NAME</replaceable>...</command></term>
553 <para>Start (activate) one or more units specified on the
558 <term><command>stop <replaceable>NAME</replaceable>...</command></term>
561 <para>Stop (deactivate) one or more units specified on the
566 <term><command>reload <replaceable>NAME</replaceable>...</command></term>
569 <para>Asks all units listed on the command line to reload
570 their configuration. Note that this will reload the
571 service-specific configuration, not the unit configuration
572 file of systemd. If you want systemd to reload the
573 configuration file of a unit use the
574 <command>daemon-reload</command> command. In other words:
575 for the example case of Apache, this will reload Apache's
576 <filename>httpd.conf</filename> in the web server, not the
577 <filename>apache.service</filename> systemd unit
580 <para>This command should not be confused with the
581 <command>daemon-reload</command> or <command>load</command>
587 <term><command>restart <replaceable>NAME</replaceable>...</command></term>
590 <para>Restart one or more units specified on the command
591 line. If the units are not running yet they will be
596 <term><command>try-restart <replaceable>NAME</replaceable>...</command></term>
599 <para>Restart one or more units specified on the command
600 line if the units are running. Do nothing if units are not
601 running. Note that for compatibility with Red Hat init
602 scripts <command>condrestart</command> is equivalent to this
607 <term><command>reload-or-restart <replaceable>NAME</replaceable>...</command></term>
610 <para>Reload one or more units if they support it. If not,
611 restart them instead. If the units are not running yet they
612 will be started.</para>
616 <term><command>reload-or-try-restart <replaceable>NAME</replaceable>...</command></term>
619 <para>Reload one or more units if they support it. If not,
620 restart them instead. Do nothing if the units are not
621 running. Note that for compatibility with SysV init scripts
622 <command>force-reload</command> is equivalent to this
627 <term><command>isolate <replaceable>NAME</replaceable></command></term>
630 <para>Start the unit specified on the command line and its
631 dependencies and stop all others.</para>
633 <para>This is similar to changing the runlevel in a
634 traditional init system. The <command>isolate</command>
635 command will immediately stop processes that are not enabled
636 in the new unit, possibly including the graphical
637 environment or terminal you are currently using.</para>
639 <para>Note that this is allowed only on units where
640 <option>AllowIsolate=</option> is enabled. See
641 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
646 <term><command>kill <replaceable>NAME</replaceable>...</command></term>
649 <para>Send a signal to one or more processes of the
650 unit. Use <option>--kill-who=</option> to select which
651 process to kill. Use <option>--kill-mode=</option> to select
652 the kill mode and <option>--signal=</option> to select the
653 signal to send.</para>
657 <term><command>is-active <replaceable>NAME</replaceable>...</command></term>
660 <para>Check whether any of the specified units are active
661 (i.e. running). Returns an exit code 0 if at least one is
662 active, non-zero otherwise. Unless <option>--quiet</option>
663 is specified this will also print the current unit state to
668 <term><command>is-failed <replaceable>NAME</replaceable>...</command></term>
671 <para>Check whether any of the specified units are failed.
672 Returns an exit code 0 if at least one is failed, non-zero
673 otherwise. Unless <option>--quiet</option> is specified this
674 will also print the current unit state to
679 <term><command>status [<replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...]</command></term>
682 <para>Show terse runtime status information about one or
683 more units, followed by most recent log data from the
684 journal. If no units are specified, show all units (subject
685 to limitations specified with <option>-t</option>). If a PID
686 is passed show information about the unit the process
689 <para>This function is intended to generate human-readable
690 output. If you are looking for computer-parsable output, use
691 <command>show</command> instead.</para>
695 <term><command>show [<replaceable>NAME</replaceable>...|<replaceable>JOB</replaceable>...]</command></term>
698 <para>Show properties of one or more units, jobs, or the
699 manager itself. If no argument is specified properties of
700 the manager will be shown. If a unit name is specified
701 properties of the unit is shown, and if a job id is
702 specified properties of the job is shown. By default, empty
703 properties are suppressed. Use <option>--all</option> to
704 show those too. To select specific properties to show use
705 <option>--property=</option>. This command is intended to be
706 used whenever computer-parsable output is required. Use
707 <command>status</command> if you are looking for formatted
708 human-readable output.</para>
713 <term><command>get-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable>...</command></term>
716 <para>Retrieve the specified control group attributes of the
717 specified unit. Takes a unit name and one or more attribute
718 names such as <literal>cpu.shares</literal>. This will
719 output the current values of the specified attributes,
720 separated by new-lines. For attributes that take list of
721 items the output will be new-line separated, too. This
722 operation will always try to retrieve the data in question
723 from the kernel first, and if that is not available use the
724 configured values instead. Instead of low-level control
725 group attribute names high-level pretty names may be used,
726 as used for unit execution environment configuration, see
727 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
728 for details. For example, passing
729 <literal>memory.limit_in_bytes</literal> and
730 <literal>MemoryLimit</literal> is equivalent.</para>
735 <term><command>set-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable> <replaceable>VALUE</replaceable>...</command></term>
738 <para>Set the specified control group attribute of the
739 specified unit to the specified value. Takes a unit
740 name and an attribute name such as
741 <literal>cpu.shares</literal>, plus one or more values
742 (multiple values may only be used for attributes that take
743 multiple values). This operation will immediately update the
744 kernel attribute for this unit and persistently store this
745 setting for later reboots (unless <option>--runtime</option>
746 is passed, in which case the setting is not saved
747 persistently and only valid until the next reboot.) Instead
748 of low-level control group attribute names high-level pretty
749 names may be used, as used for unit execution environment
751 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
752 for details. For example, passing
753 <literal>memory.limit_in_bytes</literal> and
754 <literal>MemoryLimit</literal> is equivalent. This operation
755 will implicitly create a control group for the unit in the
756 controller the attribute belongs to, if needed. For
757 attributes that take multiple values, this operation will
758 append the specified values to the previously set values
759 list (use <command>unset-cgroup-attr</command> to reset the
760 list explicitly). For attributes that take a single value
761 only the list will be reset implicitly.</para>
766 <term><command>unset-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable>...</command></term>
768 <listitem><para>Unset the specified control group attributes
769 of the specified unit. Takes a unit name and one or more
770 attribut names such as <literal>cpu.shares</literal>. This
771 operation might or might not have an immediate effect on the
772 current kernel attribute value. This will remove any
773 persistently stored configuration values for this attribute
774 (as set with <command>set-cgroup-attr</command> before),
775 unless <option>--runtime</option> is passed, in which case the
776 configuration is reset only until the next reboot. Again,
777 high-level control group attributes may be used instead of the
778 low-level kernel ones. For attributes which take multiple
779 values, all currently set values are reset.</para>
784 <term><command>set-cgroup <replaceable>NAME</replaceable> <replaceable>CGROUP</replaceable>...</command></term>
785 <term><command>unset-cgroup <replaceable>NAME</replaceable> <replaceable>CGROUP</replaceable>...</command></term>
787 <listitem><para>Add or remove a unit to/from a specific
788 control group hierarchy and/or control group path. Takes a
789 unit name, plus a control group specification in the syntax
790 <replaceable>CONTROLLER</replaceable>:<replaceable>PATH</replaceable>
791 or <replaceable>CONTROLLER</replaceable>. In the latter syntax
792 (where the path is omitted) the default unit control group
793 path is implied. Examples: <literal>cpu</literal> or
794 <literal>cpu:/foo/bar</literal>. If a unit is removed from a
795 control group hierarchy all its processes will be moved to the
796 root group of the hierarchy and all control group attributes
797 will be reset. These operations are immediately reflected in
798 the kernel hierarchy, and stored persistently to disk (unless
799 <option>--runtime</option> is passed).</para>
804 <term><command>help <replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...</command></term>
807 <para>Show manual pages for one or more units, if
808 available. If a PID is passed the manual pages for the unit
809 the process of the PID belongs to is
815 <term><command>reset-failed [<replaceable>NAME</replaceable>...]</command></term>
818 <para>Reset the <literal>failed</literal> state of the
819 specified units, or if no unit name is passed of all
820 units. When a unit fails in some way (i.e. process exiting
821 with non-zero error code, terminating abnormally or timing
822 out) it will automatically enter the
823 <literal>failed</literal> state and its exit code and status
824 is recorded for introspection by the administrator until the
825 service is restarted or reset with this command.</para>
830 <term><command>list-unit-files</command></term>
833 <para>List installed unit files.</para>
838 <term><command>enable <replaceable>NAME</replaceable>...</command></term>
841 <para>Enable one or more unit files or unit file instances,
842 as specified on the command line. This will create a number
843 of symlinks as encoded in the <literal>[Install]</literal>
844 sections of the unit files. After the symlinks have been
845 created the systemd configuration is reloaded (in a way that
846 is equivalent to <command>daemon-reload</command>) to ensure
847 the changes are taken into account immediately. Note that
848 this does not have the effect that any of the units enabled
849 are also started at the same time. If this is desired a
850 separate <command>start</command> command must be invoked
851 for the unit. Also note that in case of instance enablement,
852 symlinks named same as instances are created in install
853 location, however they all point to the same template unit
856 <para>This command will print the actions executed. This
857 output may be suppressed by passing <option>--quiet</option>.
860 <para>Note that this operation creates only the suggested
861 symlinks for the units. While this command is the
862 recommended way to manipulate the unit configuration
863 directory, the administrator is free to make additional
864 changes manually, by placing or removing symlinks in the
865 directory. This is particularly useful to create
866 configurations that deviate from the suggested default
867 installation. In this case the administrator must make sure
868 to invoke <command>daemon-reload</command> manually as
869 necessary, to ensure his changes are taken into account.
872 <para>Enabling units should not be confused with starting
873 (activating) units, as done by the <command>start</command>
874 command. Enabling and starting units is orthogonal: units
875 may be enabled without being started and started without
876 being enabled. Enabling simply hooks the unit into various
877 suggested places (for example, so that the unit is
878 automatically started on boot or when a particular kind of
879 hardware is plugged in). Starting actually spawns the daemon
880 process (in case of service units), or binds the socket (in
881 case of socket units), and so on.</para>
883 <para>Depending on whether <option>--system</option>,
884 <option>--user</option> or <option>--global</option> is
885 specified this enables the unit for the system, for the
886 calling user only or for all future logins of all
887 users. Note that in the last case no systemd daemon
888 configuration is reloaded.</para>
893 <term><command>disable <replaceable>NAME</replaceable>...</command></term>
896 <para>Disables one or more units. This removes all symlinks
897 to the specified unit files from the unit configuration
898 directory, and hence undoes the changes made by
899 <command>enable</command>. Note however that this removes
900 all symlinks to the unit files (i.e. including manual
901 additions), not just those actually created by
902 <command>enable</command>. This call implicitly reloads the
903 systemd daemon configuration after completing the disabling
904 of the units. Note that this command does not implicitly
905 stop the units that are being disabled. If this is desired
906 an additional <command>stop</command> command should be
907 executed afterwards.</para>
909 <para>This command will print the actions executed. This
910 output may be suppressed by passing <option>--quiet</option>.
913 <para>This command honors <option>--system</option>,
914 <option>--user</option>, <option>--global</option> in a
915 similar way as <command>enable</command>.</para>
920 <term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>
923 <para>Checks whether any of the specified unit files are
924 enabled (as with <command>enable</command>). Returns an exit
925 code of 0 if at least one is enabled, non-zero
926 otherwise. Prints the current enable status. To suppress
927 this output use <option>--quiet</option>.</para>
932 <term><command>reenable <replaceable>NAME</replaceable>...</command></term>
935 <para>Reenable one or more unit files, as specified on the
936 command line. This is a combination of
937 <command>disable</command> and <command>enable</command> and
938 is useful to reset the symlinks a unit is enabled with to
939 the defaults configured in the <literal>[Install]</literal>
940 section of the unit file.</para>
945 <term><command>preset <replaceable>NAME</replaceable>...</command></term>
948 <para>Reset one or more unit files, as specified on the
949 command line, to the defaults configured in the preset
950 policy files. This has the same effect as
951 <command>disable</command> or <command>enable</command>,
952 depending how the unit is listed in the preset files. For
953 more information on preset policy format see
954 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
955 For more information on the concept of presets please
957 <ulink url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
963 <term><command>mask <replaceable>NAME</replaceable>...</command></term>
966 <para>Mask one or more unit files, as specified on the
967 command line. This will link these units to
968 <filename>/dev/null</filename>, making it impossible to
969 start them. This is a stronger version of
970 <command>disable</command>, since it prohibits all kinds of
971 activation of the unit, including manual activation. Use
972 this option with care.</para>
977 <term><command>unmask <replaceable>NAME</replaceable>...</command></term>
980 <para>Unmask one or more unit files, as specified on the
981 command line. This will undo the effect of
982 <command>mask</command>.</para>
987 <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
990 <para>Link a unit file that is not in the unit file search
991 paths into the unit file search path. This requires an
992 absolute path to a unit file. The effect of this can be
993 undone with <command>disable</command>. The effect of this
994 command is that a unit file is available for
995 <command>start</command> and other commands although it
996 isn't installed directly in the unit search path.</para>
1001 <term><command>load <replaceable>NAME</replaceable>...</command></term>
1004 <para>Load one or more units specified on the command
1005 line. This will simply load their configuration from disk,
1006 but not start them. To start them you need to use the
1007 <command>start</command> command which will implicitly load
1008 a unit that has not been loaded yet. Note that systemd
1009 garbage collects loaded units that are not active or
1010 referenced by an active unit. This means that units loaded
1011 this way will usually not stay loaded for long. Also note
1012 that this command cannot be used to reload unit
1013 configuration. Use the <command>daemon-reload</command>
1014 command for that. All in all, this command is of little use
1015 except for debugging.</para>
1017 <para>This command should not be confused with the
1018 <command>daemon-reload</command> or
1019 <command>reload</command>.</para>
1023 <term><command>list-jobs</command></term>
1026 <para>List jobs that are in progress.</para>
1030 <term><command>cancel <replaceable>JOB</replaceable>...</command></term>
1033 <para>Cancel one or more jobs specified on the command line
1034 by their numeric job IDs. If no job id is specified, cancel
1035 all pending jobs.</para>
1039 <term><command>dump</command></term>
1042 <para>Dump server status. This will output a (usually very
1043 long) human readable manager status dump. Its format is
1044 subject to change without notice and should not be parsed by
1045 applications.</para>
1049 <term><command>list-dependencies <replaceable>NAME</replaceable></command></term>
1052 <para>Shows required and wanted units of the specified
1053 unit. If no unit is specified
1054 <filename>default.target</filename> is implied. Target units
1055 are recursively expanded. When <option>--all</option> is
1056 passed all other units are recursively expanded as
1061 <term><command>snapshot [<replaceable>NAME</replaceable>]</command></term>
1064 <para>Create a snapshot. If a snapshot name is specified,
1065 the new snapshot will be named after it. If none is
1066 specified an automatic snapshot name is generated. In either
1067 case, the snapshot name used is printed to STDOUT, unless
1068 <option>--quiet</option> is specified.</para>
1070 <para>A snapshot refers to a saved state of the systemd
1071 manager. It is implemented itself as a unit that is
1072 generated dynamically with this command and has dependencies
1073 on all units active at the time. At a later time the user
1074 may return to this state by using the
1075 <command>isolate</command> command on the snapshot unit.
1078 <para>Snapshots are only useful for saving and restoring
1079 which units are running or are stopped, they do not
1080 save/restore any other state. Snapshots are dynamic and lost
1085 <term><command>delete <replaceable>NAME</replaceable>...</command></term>
1088 <para>Remove a snapshot previously created with
1089 <command>snapshot</command>.</para>
1093 <term><command>daemon-reload</command></term>
1096 <para>Reload systemd manager configuration. This will reload
1097 all unit files and recreate the entire dependency
1098 tree. While the daemon is reloaded, all sockets systemd
1099 listens on on behalf of user configuration will stay
1100 accessible.</para> <para>This command should not be confused
1101 with the <command>load</command> or
1102 <command>reload</command> commands.</para>
1106 <term><command>daemon-reexec</command></term>
1109 <para>Reexecute the systemd manager. This will serialize the
1110 manager state, reexecute the process and deserialize the
1111 state again. This command is of little use except for
1112 debugging and package upgrades. Sometimes it might be
1113 helpful as a heavy-weight <command>daemon-reload</command>.
1114 While the daemon is reexecuted all sockets systemd listens
1115 on on behalf of user configuration will stay accessible.
1120 <term><command>show-environment</command></term>
1123 <para>Dump the systemd manager environment block. The
1124 environment block will be dumped in straight-forward form
1125 suitable for sourcing into a shell script. This environment
1126 block will be passed to all processes the manager
1131 <term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>
1134 <para>Set one or more systemd manager environment variables,
1135 as specified on the command line.</para>
1139 <term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>
1142 <para>Unset one or more systemd manager environment
1143 variables. If only a variable name is specified it will be
1144 removed regardless of its value. If a variable and a value
1145 are specified the variable is only removed if it has the
1146 specified value.</para>
1150 <term><command>default</command></term>
1153 <para>Enter default mode. This is mostly equivalent to
1154 <command>isolate default.target</command>.</para>
1158 <term><command>rescue</command></term>
1161 <para>Enter rescue mode. This is mostly equivalent to
1162 <command>isolate rescue.target</command> but also prints a
1163 wall message to all users.</para>
1167 <term><command>emergency</command></term>
1170 <para>Enter emergency mode. This is mostly equivalent to
1171 <command>isolate emergency.target</command> but also prints
1172 a wall message to all users.</para>
1176 <term><command>halt</command></term>
1179 <para>Shut down and halt the system. This is mostly equivalent to
1180 <command>start halt.target --irreversible</command> but also
1181 prints a wall message to all users. If combined with
1182 <option>--force</option> shutdown of all running services is
1183 skipped, however all processes are killed and all file
1184 systems are unmounted or mounted read-only, immediately
1185 followed by the system halt. If <option>--force</option> is
1186 specified twice the operation is immediately executed
1187 without terminating any processes or unmounting any file
1188 systems. This may result in data loss.</para>
1192 <term><command>poweroff</command></term>
1195 <para>Shut down and power-off the system. This is mostly
1196 equivalent to <command>start poweroff.target --irreversible</command>
1197 but also prints a wall message to all users. If combined with
1198 <option>--force</option> shutdown of all running services is
1199 skipped, however all processes are killed and all file
1200 systems are unmounted or mounted read-only, immediately
1201 followed by the powering off. If <option>--force</option> is
1202 specified twice the operation is immediately executed
1203 without terminating any processes or unmounting any file
1204 systems. This may result in data loss.</para>
1208 <term><command>reboot</command></term>
1211 <para>Shut down and reboot the system. This is mostly
1212 equivalent to <command>start reboot.target --irreversible</command>
1213 but also prints a wall message to all users. If combined with
1214 <option>--force</option> shutdown of all running services is
1215 skipped, however all processes are killed and all file
1216 systems are unmounted or mounted read-only, immediately
1217 followed by the reboot. If <option>--force</option> is
1218 specified twice the operation is immediately executed
1219 without terminating any processes or unmounting any file
1220 systems. This may result in data loss.</para>
1224 <term><command>kexec</command></term>
1227 <para>Shut down and reboot the system via kexec. This is
1228 mostly equivalent to <command>start kexec.target --irreversible</command>
1229 but also prints a wall message to all users. If combined
1230 with <option>--force</option> shutdown of all running
1231 services is skipped, however all processes are killed and
1232 all file systems are unmounted or mounted read-only,
1233 immediately followed by the reboot.</para>
1237 <term><command>exit</command></term>
1240 <para>Ask the systemd manager to quit. This is only
1241 supported for user service managers (i.e. in conjunction
1242 with the <option>--user</option> option) and will fail
1248 <term><command>suspend</command></term>
1251 <para>Suspend the system. This will trigger activation of
1252 the special <filename>suspend.target</filename> target.
1257 <term><command>hibernate</command></term>
1260 <para>Hibernate the system. This will trigger activation of
1261 the special <filename>hibernate.target</filename> target.
1266 <term><command>hybrid-sleep</command></term>
1269 <para>Hibernate and suspend the system. This will trigger
1270 activation of the special
1271 <filename>hybrid-sleep.target</filename> target.</para>
1275 <term><command>switch-root <replaceable>ROOT</replaceable> [<replaceable>INIT</replaceable>]</command></term>
1278 <para>Switches to a different root directory and executes a
1279 new system manager process below it. This is intended for
1280 usage in initial RAM disks ("initrd"), and will transition
1281 from the initrd's system manager process (a.k.a "init"
1282 process) to the main system manager process. Takes two
1283 arguments: the directory to make the new root directory, and
1284 the path to the new system manager binary below it to
1285 execute as PID 1. If the latter is omitted or the empty
1286 string, a systemd binary will automatically be searched for
1287 and used as init. If the system manager path is omitted or
1288 equal to the empty string the state of the initrd's system
1289 manager process is passed to the main system manager, which
1290 allows later introspection of the state of the services
1291 involved in the initrd boot.</para>
1299 <title>Exit status</title>
1301 <para>On success 0 is returned, a non-zero failure
1302 code otherwise.</para>
1306 <title>Environment</title>
1308 <variablelist class='environment-variables'>
1310 <term><varname>$SYSTEMD_PAGER</varname></term>
1313 <para>Pager to use when <option>--no-pager</option> is not
1314 given; overrides <varname>$PAGER</varname>. Setting this to
1315 an empty string or the value <literal>cat</literal> is
1316 equivalent to passing
1317 <option>--no-pager</option>.</para>
1324 <title>See Also</title>
1326 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1327 <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1328 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1329 <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1330 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1331 <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1332 <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1333 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>