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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-seperated 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 units, regardless of
137 their state, including inactive units. When showing
138 unit/job/manager properties, show all properties regardless
139 whether they are set or not.</para>
144 <term><option>--failed</option></term>
147 <para>When listing units, show only failed units. Do not
148 confuse with <option>--fail</option>.</para>
153 <term><option>--full</option></term>
156 <para>Do not ellipsize unit names, cgroup members, and
157 truncate unit descriptions in the output of
158 <command>list-units</command> and
159 <command>list-jobs</command>.</para>
164 <term><option>--fail</option></term>
167 <para>If the requested operation conflicts with a pending
168 unfinished job, fail the command. If this is not specified
169 the requested operation will replace the pending job, if
170 necessary. Do not confuse with
171 <option>--failed</option>.</para>
176 <term><option>--show-types</option></term>
179 <para>When showing sockets, show the type of the socket.</para>
184 <term><option>--irreversible</option></term>
187 <para>Mark this transaction's jobs as irreversible. This prevents
188 future conflicting transactions from replacing these jobs.
189 The jobs can still be cancelled using the <command>cancel</command>
195 <term><option>--ignore-dependencies</option></term>
198 <para>When enqueuing a new job ignore all its dependencies
199 and execute it immediately. If passed no required units of
200 the unit passed will be pulled in, and no ordering
201 dependencies will be honored. This is mostly a debugging and
202 rescue tool for the administrator and should not be used by
208 <term><option>-i</option></term>
209 <term><option>--ignore-inhibitors</option></term>
212 <para>When system shutdown or a sleep state is requested,
213 ignore inhibitor locks. Applications can establish inhibitor
214 locks to avoid that certain important operations (such as CD
215 burning or suchlike) are interrupted by system shutdown or a
216 sleep state. Any user may take these locks and privileged
217 users may override these locks. If any locks are taken,
218 shutdown and sleep state requests will normally fail
219 (regardless if privileged or not) and a list of active locks
220 is printed. However if <option>--ignore-inhibitors</option>
221 is specified the locks are ignored and not printed, and the
222 operation attempted anyway, possibly requiring additional
228 <term><option>-q</option></term>
229 <term><option>--quiet</option></term>
232 <para>Suppress output to standard output in
233 <command>snapshot</command>,
234 <command>is-active</command>,
235 <command>is-failed</command>,
236 <command>enable</command> and
237 <command>disable</command>.</para>
242 <term><option>--no-block</option></term>
245 <para>Do not synchronously wait for the requested operation
246 to finish. If this is not specified the job will be
247 verified, enqueued and <command>systemctl</command> will
248 wait until it is completed. By passing this argument it is
249 only verified and enqueued.</para>
254 <term><option>--no-legend</option></term>
257 <para>Do not print a legend, i.e. the column headers and
258 the footer with hints.</para>
263 <term><option>--no-pager</option></term>
266 <para>Do not pipe output into a pager.</para>
271 <term><option>--system</option></term>
274 <para>Talk to the systemd system manager. (Default)</para>
279 <term><option>--user</option></term>
282 <para>Talk to the systemd manager of the calling
288 <term><option>--no-wall</option></term>
291 <para>Don't send wall message before halt, power-off,
297 <term><option>--global</option></term>
300 <para>When used with <command>enable</command> and
301 <command>disable</command>, operate on the global user
302 configuration directory, thus enabling or disabling a unit
303 file globally for all future logins of all users.</para>
308 <term><option>--no-reload</option></term>
311 <para>When used with <command>enable</command> and
312 <command>disable</command>, do not implicitly reload daemon
313 configuration after executing the changes.</para>
318 <term><option>--no-ask-password</option></term>
321 <para>When used with <command>start</command> and related
322 commands, disables asking for passwords. Background services
323 may require input of a password or passphrase string, for
324 example to unlock system hard disks or cryptographic
325 certificates. Unless this option is specified and the
326 command is invoked from a terminal
327 <command>systemctl</command> will query the user on the
328 terminal for the necessary secrets. Use this option to
329 switch this behavior off. In this case the password must be
330 supplied by some other means (for example graphical password
331 agents) or the service might fail. This also disables
332 querying the user for authentication for privileged
339 <term><option>--kill-who=</option></term>
342 <para>When used with <command>kill</command>, choose which
343 processes to kill. Must be one of <option>main</option>,
344 <option>control</option> or <option>all</option> to select
345 whether to kill only the main process of the unit, the
346 control process or all processes of the unit. If omitted
347 defaults to <option>all</option>.</para>
353 <term><option>-s</option></term>
354 <term><option>--signal=</option></term>
357 <para>When used with <command>kill</command>, choose which
358 signal to send to selected processes. Must be one of the
359 well known signal specifiers such as SIGTERM, SIGINT or
360 SIGSTOP. If omitted defaults to
361 <option>SIGTERM</option>.</para>
366 <term><option>-f</option></term>
367 <term><option>--force</option></term>
370 <para>When used with <command>enable</command>, overwrite
371 any existing conflicting symlinks.</para>
373 <para>When used with <command>halt</command>,
374 <command>poweroff</command>, <command>reboot</command> or
375 <command>kexec</command> execute the selected operation
376 without shutting down all units. However, all processes will
377 be killed forcibly and all file systems are unmounted or
378 remounted read-only. This is hence a drastic but relatively
379 safe option to request an immediate reboot. If
380 <option>--force</option> is specified twice for these
381 operations, they will be executed immediately without
382 terminating any processes or umounting any file
383 systems. Warning: specifying <option>--force</option> twice
384 with any of these operations might result in data
390 <term><option>--root=</option></term>
394 <command>enable</command>/<command>disable</command>/<command>is-enabled</command>
395 (and related commands), use alternative root path when
396 looking for unit files.</para>
402 <term><option>--runtime</option></term>
405 <para>When used with <command>enable</command>,
406 <command>disable</command>, <command>is-enabled</command>
407 (and related commands), make changes only temporarily, so
408 that they are lost on the next reboot. This will have the
409 effect that changes are not made in subdirectories of
410 <filename>/etc</filename> but in <filename>/run</filename>,
411 with identical immediate effects, however, since the latter
412 is lost on reboot, the changes are lost too.</para>
414 <para>Similar, when used with
415 <command>set-cgroup-attr</command>,
416 <command>unset-cgroup-attr</command>,
417 <command>set-cgroup</command> and
418 <command>unset-cgroup</command>, make changes only
419 temporarily, so that they are lost on the next
425 <term><option>-H</option></term>
426 <term><option>--host</option></term>
429 <para>Execute operation remotely. Specify a hostname, or
430 username and hostname separated by @, to connect to. This
431 will use SSH to talk to the remote systemd
437 <term><option>-P</option></term>
438 <term><option>--privileged</option></term>
441 <para>Acquire privileges via PolicyKit before executing the
447 <term><option>-n</option></term>
448 <term><option>--lines=</option></term>
451 <para>When used with <command>status</command> controls the
452 number of journal lines to show, counting from the most
453 recent ones. Takes a positive integer argument. Defaults to
459 <term><option>-o</option></term>
460 <term><option>--output=</option></term>
463 <para>When used with <command>status</command> controls the
464 formatting of the journal entries that are shown. For the
465 available choices see
466 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
467 Defaults to <literal>short</literal>.</para>
475 <title>Commands</title>
477 <para>The following commands are understood:</para>
481 <term><command>list-units</command></term>
484 <para>List known units (subject to limitations specified
485 with <option>-t</option>).</para>
487 <para>This is the default command.</para>
492 <term><command>list-sockets</command></term>
495 <para>List socket units ordered by the listening address. Produces output
498 LISTEN UNIT ACTIVATES
499 /dev/initctl systemd-initctl.socket systemd-initctl.service
501 [::]:22 sshd.socket sshd.service
502 kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
506 Note: because the addresses might contains spaces, this output
507 is not suitable for programatic consumption.
510 <para>See also the options <option>--show-types</option>,
511 <option>--all</option>, and <option>--failed</option>.</para>
516 <term><command>start <replaceable>NAME</replaceable>...</command></term>
519 <para>Start (activate) one or more units specified on the
524 <term><command>stop <replaceable>NAME</replaceable>...</command></term>
527 <para>Stop (deactivate) one or more units specified on the
532 <term><command>reload <replaceable>NAME</replaceable>...</command></term>
535 <para>Asks all units listed on the command line to reload
536 their configuration. Note that this will reload the
537 service-specific configuration, not the unit configuration
538 file of systemd. If you want systemd to reload the
539 configuration file of a unit use the
540 <command>daemon-reload</command> command. In other words:
541 for the example case of Apache, this will reload Apache's
542 <filename>httpd.conf</filename> in the web server, not the
543 <filename>apache.service</filename> systemd unit
546 <para>This command should not be confused with the
547 <command>daemon-reload</command> or <command>load</command>
553 <term><command>restart <replaceable>NAME</replaceable>...</command></term>
556 <para>Restart one or more units specified on the command
557 line. If the units are not running yet they will be
562 <term><command>try-restart <replaceable>NAME</replaceable>...</command></term>
565 <para>Restart one or more units specified on the command
566 line if the units are running. Do nothing if units are not
567 running. Note that for compatibility with Red Hat init
568 scripts <command>condrestart</command> is equivalent to this
573 <term><command>reload-or-restart <replaceable>NAME</replaceable>...</command></term>
576 <para>Reload one or more units if they support it. If not,
577 restart them instead. If the units are not running yet they
578 will be started.</para>
582 <term><command>reload-or-try-restart <replaceable>NAME</replaceable>...</command></term>
585 <para>Reload one or more units if they support it. If not,
586 restart them instead. Do nothing if the units are not
587 running. Note that for compatibility with SysV init scripts
588 <command>force-reload</command> is equivalent to this
593 <term><command>isolate <replaceable>NAME</replaceable></command></term>
596 <para>Start the unit specified on the command line and its
597 dependencies and stop all others.</para>
599 <para>This is similar to changing the runlevel in a
600 traditional init system. The <command>isolate</command>
601 command will immediately stop processes that are not enabled
602 in the new unit, possibly including the graphical
603 environment or terminal you are currently using.</para>
605 <para>Note that this is allowed only on units where
606 <option>AllowIsolate=</option> is enabled. See
607 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
612 <term><command>kill <replaceable>NAME</replaceable>...</command></term>
615 <para>Send a signal to one or more processes of the
616 unit. Use <option>--kill-who=</option> to select which
617 process to kill. Use <option>--kill-mode=</option> to select
618 the kill mode and <option>--signal=</option> to select the
619 signal to send.</para>
623 <term><command>is-active <replaceable>NAME</replaceable>...</command></term>
626 <para>Check whether any of the specified units are active
627 (i.e. running). Returns an exit code 0 if at least one is
628 active, non-zero otherwise. Unless <option>--quiet</option>
629 is specified this will also print the current unit state to
634 <term><command>is-failed <replaceable>NAME</replaceable>...</command></term>
637 <para>Check whether any of the specified units are failed.
638 Returns an exit code 0 if at least one is failed, non-zero
639 otherwise. Unless <option>--quiet</option> is specified this
640 will also print the current unit state to
645 <term><command>status [<replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...]</command></term>
648 <para>Show terse runtime status information about one or
649 more units, followed by most recent log data from the
650 journal. If no units are specified, show all units (subject
651 to limitations specified with <option>-t</option>). If a PID
652 is passed show information about the unit the process
655 <para>This function is intended to generate human-readable
656 output. If you are looking for computer-parsable output, use
657 <command>show</command> instead.</para>
661 <term><command>show [<replaceable>NAME</replaceable>...|<replaceable>JOB</replaceable>...]</command></term>
664 <para>Show properties of one or more units, jobs, or the
665 manager itself. If no argument is specified properties of
666 the manager will be shown. If a unit name is specified
667 properties of the unit is shown, and if a job id is
668 specified properties of the job is shown. By default, empty
669 properties are suppressed. Use <option>--all</option> to
670 show those too. To select specific properties to show use
671 <option>--property=</option>. This command is intended to be
672 used whenever computer-parsable output is required. Use
673 <command>status</command> if you are looking for formatted
674 human-readable output.</para>
679 <term><command>get-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable>...</command></term>
682 <para>Retrieve the specified control group attributes of the
683 specified unit. Takes a unit name and one or more attribute
684 names such as <literal>cpu.shares</literal>. This will
685 output the current values of the specified attributes,
686 separated by new-lines. For attributes that take list of
687 items the output will be new-line separated, too. This
688 operation will always try to retrieve the data in question
689 from the kernel first, and if that is not available use the
690 configured values instead. Instead of low-level control
691 group attribute names high-level pretty names may be used,
692 as used for unit execution environment configuration, see
693 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
694 for details. For example, passing
695 <literal>memory.limit_in_bytes</literal> and
696 <literal>MemoryLimit</literal> is equivalent.</para>
701 <term><command>set-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable> <replaceable>VALUE</replaceable>...</command></term>
704 <para>Set the specified control group attribute of the
705 specified unit to the specified value. Takes a unit
706 name and an attribute name such as
707 <literal>cpu.shares</literal>, plus one or more values
708 (multiple values may only be used for attributes that take
709 multiple values). This operation will immediately update the
710 kernel attribute for this unit and persistently store this
711 setting for later reboots (unless <option>--runtime</option>
712 is passed, in which case the setting is not saved
713 persistently and only valid until the next reboot.) Instead
714 of low-level control group attribute names high-level pretty
715 names may be used, as used for unit execution environment
717 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
718 for details. For example, passing
719 <literal>memory.limit_in_bytes</literal> and
720 <literal>MemoryLimit</literal> is equivalent. This operation
721 will implicitly create a control group for the unit in the
722 controller the attribute belongs to, if needed. For
723 attributes that take multiple values, this operation will
724 append the specified values to the previously set values
725 list (use <command>unset-cgroup-attr</command> to reset the
726 list explicitly). For attributes that take a single value
727 only the list will be reset implicitly.</para>
732 <term><command>unset-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable>...</command></term>
734 <listitem><para>Unset the specified control group attributes
735 of the specified unit. Takes a unit name and one or more
736 attribut names such as <literal>cpu.shares</literal>. This
737 operation might or might not have an immediate effect on the
738 current kernel attribute value. This will remove any
739 persistently stored configuration values for this attribute
740 (as set with <command>set-cgroup-attr</command> before),
741 unless <option>--runtime</option> is passed, in which case the
742 configuration is reset only until the next reboot. Again,
743 high-level control group attributes may be used instead of the
744 low-level kernel ones. For attributes which take multiple
745 values, all currently set values are reset.</para>
750 <term><command>set-cgroup <replaceable>NAME</replaceable> <replaceable>CGROUP</replaceable>...</command></term>
751 <term><command>unset-cgroup <replaceable>NAME</replaceable> <replaceable>CGROUP</replaceable>...</command></term>
753 <listitem><para>Add or remove a unit to/from a specific
754 control group hierarchy and/or control group path. Takes a
755 unit name, plus a control group specification in the syntax
756 <replaceable>CONTROLLER</replaceable>:<replaceable>PATH</replaceable>
757 or <replaceable>CONTROLLER</replaceable>. In the latter syntax
758 (where the path is omitted) the default unit control group
759 path is implied. Examples: <literal>cpu</literal> or
760 <literal>cpu:/foo/bar</literal>. If a unit is removed from a
761 control group hierarchy all its processes will be moved to the
762 root group of the hierarchy and all control group attributes
763 will be reset. These operations are immediately reflected in
764 the kernel hierarchy, and stored persistently to disk (unless
765 <option>--runtime</option> is passed).</para>
770 <term><command>help <replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...</command></term>
773 <para>Show manual pages for one or more units, if
774 available. If a PID is passed the manual pages for the unit
775 the process of the PID belongs to is
781 <term><command>reset-failed [<replaceable>NAME</replaceable>...]</command></term>
784 <para>Reset the <literal>failed</literal> state of the
785 specified units, or if no unit name is passed of all
786 units. When a unit fails in some way (i.e. process exiting
787 with non-zero error code, terminating abnormally or timing
788 out) it will automatically enter the
789 <literal>failed</literal> state and its exit code and status
790 is recorded for introspection by the administrator until the
791 service is restarted or reset with this command.</para>
796 <term><command>list-unit-files</command></term>
799 <para>List installed unit files.</para>
804 <term><command>enable <replaceable>NAME</replaceable>...</command></term>
807 <para>Enable one or more unit files or unit file instances,
808 as specified on the command line. This will create a number
809 of symlinks as encoded in the <literal>[Install]</literal>
810 sections of the unit files. After the symlinks have been
811 created the systemd configuration is reloaded (in a way that
812 is equivalent to <command>daemon-reload</command>) to ensure
813 the changes are taken into account immediately. Note that
814 this does not have the effect that any of the units enabled
815 are also started at the same time. If this is desired a
816 separate <command>start</command> command must be invoked
817 for the unit. Also note that in case of instance enablement,
818 symlinks named same as instances are created in install
819 location, however they all point to the same template unit
822 <para>This command will print the actions executed. This
823 output may be suppressed by passing <option>--quiet</option>.
826 <para>Note that this operation creates only the suggested
827 symlinks for the units. While this command is the
828 recommended way to manipulate the unit configuration
829 directory, the administrator is free to make additional
830 changes manually, by placing or removing symlinks in the
831 directory. This is particularly useful to create
832 configurations that deviate from the suggested default
833 installation. In this case the administrator must make sure
834 to invoke <command>daemon-reload</command> manually as
835 necessary, to ensure his changes are taken into account.
838 <para>Enabling units should not be confused with starting
839 (activating) units, as done by the <command>start</command>
840 command. Enabling and starting units is orthogonal: units
841 may be enabled without being started and started without
842 being enabled. Enabling simply hooks the unit into various
843 suggested places (for example, so that the unit is
844 automatically started on boot or when a particular kind of
845 hardware is plugged in). Starting actually spawns the daemon
846 process (in case of service units), or binds the socket (in
847 case of socket units), and so on.</para>
849 <para>Depending on whether <option>--system</option>,
850 <option>--user</option> or <option>--global</option> is
851 specified this enables the unit for the system, for the
852 calling user only or for all future logins of all
853 users. Note that in the last case no systemd daemon
854 configuration is reloaded.</para>
859 <term><command>disable <replaceable>NAME</replaceable>...</command></term>
862 <para>Disables one or more units. This removes all symlinks
863 to the specified unit files from the unit configuration
864 directory, and hence undoes the changes made by
865 <command>enable</command>. Note however that this removes
866 all symlinks to the unit files (i.e. including manual
867 additions), not just those actually created by
868 <command>enable</command>. This call implicitly reloads the
869 systemd daemon configuration after completing the disabling
870 of the units. Note that this command does not implicitly
871 stop the units that are being disabled. If this is desired
872 an additional <command>stop</command> command should be
873 executed afterwards.</para>
875 <para>This command will print the actions executed. This
876 output may be suppressed by passing <option>--quiet</option>.
879 <para>This command honors <option>--system</option>,
880 <option>--user</option>, <option>--global</option> in a
881 similar way as <command>enable</command>.</para>
886 <term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>
889 <para>Checks whether any of the specified unit files are
890 enabled (as with <command>enable</command>). Returns an exit
891 code of 0 if at least one is enabled, non-zero
892 otherwise. Prints the current enable status. To suppress
893 this output use <option>--quiet</option>.</para>
898 <term><command>reenable <replaceable>NAME</replaceable>...</command></term>
901 <para>Reenable one or more unit files, as specified on the
902 command line. This is a combination of
903 <command>disable</command> and <command>enable</command> and
904 is useful to reset the symlinks a unit is enabled with to
905 the defaults configured in the <literal>[Install]</literal>
906 section of the unit file.</para>
911 <term><command>preset <replaceable>NAME</replaceable>...</command></term>
914 <para>Reset one or more unit files, as specified on the
915 command line, to the defaults configured in the preset
916 policy files. This has the same effect as
917 <command>disable</command> or <command>enable</command>,
918 depending how the unit is listed in the preset files. For
919 more information on preset policy format see
920 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
921 For more information on the concept of presets please
923 <ulink url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
929 <term><command>mask <replaceable>NAME</replaceable>...</command></term>
932 <para>Mask one or more unit files, as specified on the
933 command line. This will link these units to
934 <filename>/dev/null</filename>, making it impossible to
935 start them. This is a stronger version of
936 <command>disable</command>, since it prohibits all kinds of
937 activation of the unit, including manual activation. Use
938 this option with care.</para>
943 <term><command>unmask <replaceable>NAME</replaceable>...</command></term>
946 <para>Unmask one or more unit files, as specified on the
947 command line. This will undo the effect of
948 <command>mask</command>.</para>
953 <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
956 <para>Link a unit file that is not in the unit file search
957 paths into the unit file search path. This requires an
958 absolute path to a unit file. The effect of this can be
959 undone with <command>disable</command>. The effect of this
960 command is that a unit file is available for
961 <command>start</command> and other commands although it
962 isn't installed directly in the unit search path.</para>
967 <term><command>load <replaceable>NAME</replaceable>...</command></term>
970 <para>Load one or more units specified on the command
971 line. This will simply load their configuration from disk,
972 but not start them. To start them you need to use the
973 <command>start</command> command which will implicitly load
974 a unit that has not been loaded yet. Note that systemd
975 garbage collects loaded units that are not active or
976 referenced by an active unit. This means that units loaded
977 this way will usually not stay loaded for long. Also note
978 that this command cannot be used to reload unit
979 configuration. Use the <command>daemon-reload</command>
980 command for that. All in all, this command is of little use
981 except for debugging.</para>
983 <para>This command should not be confused with the
984 <command>daemon-reload</command> or
985 <command>reload</command>.</para>
989 <term><command>list-jobs</command></term>
992 <para>List jobs that are in progress.</para>
996 <term><command>cancel <replaceable>JOB</replaceable>...</command></term>
999 <para>Cancel one or more jobs specified on the command line
1000 by their numeric job IDs. If no job id is specified, cancel
1001 all pending jobs.</para>
1005 <term><command>dump</command></term>
1008 <para>Dump server status. This will output a (usually very
1009 long) human readable manager status dump. Its format is
1010 subject to change without notice and should not be parsed by
1011 applications.</para>
1015 <term><command>list-dependencies <replaceable>NAME</replaceable></command></term>
1018 <para>Shows required and wanted units of the specified
1019 unit. If no unit is specified
1020 <filename>default.target</filename> is implied. Target units
1021 are recursively expanded. When <option>--all</option> is
1022 passed all other units are recursively expanded as
1027 <term><command>snapshot [<replaceable>NAME</replaceable>]</command></term>
1030 <para>Create a snapshot. If a snapshot name is specified,
1031 the new snapshot will be named after it. If none is
1032 specified an automatic snapshot name is generated. In either
1033 case, the snapshot name used is printed to STDOUT, unless
1034 <option>--quiet</option> is specified.</para>
1036 <para>A snapshot refers to a saved state of the systemd
1037 manager. It is implemented itself as a unit that is
1038 generated dynamically with this command and has dependencies
1039 on all units active at the time. At a later time the user
1040 may return to this state by using the
1041 <command>isolate</command> command on the snapshot unit.
1044 <para>Snapshots are only useful for saving and restoring
1045 which units are running or are stopped, they do not
1046 save/restore any other state. Snapshots are dynamic and lost
1051 <term><command>delete <replaceable>NAME</replaceable>...</command></term>
1054 <para>Remove a snapshot previously created with
1055 <command>snapshot</command>.</para>
1059 <term><command>daemon-reload</command></term>
1062 <para>Reload systemd manager configuration. This will reload
1063 all unit files and recreate the entire dependency
1064 tree. While the daemon is reloaded, all sockets systemd
1065 listens on on behalf of user configuration will stay
1066 accessible.</para> <para>This command should not be confused
1067 with the <command>load</command> or
1068 <command>reload</command> commands.</para>
1072 <term><command>daemon-reexec</command></term>
1075 <para>Reexecute the systemd manager. This will serialize the
1076 manager state, reexecute the process and deserialize the
1077 state again. This command is of little use except for
1078 debugging and package upgrades. Sometimes it might be
1079 helpful as a heavy-weight <command>daemon-reload</command>.
1080 While the daemon is reexecuted all sockets systemd listens
1081 on on behalf of user configuration will stay accessible.
1086 <term><command>show-environment</command></term>
1089 <para>Dump the systemd manager environment block. The
1090 environment block will be dumped in straight-forward form
1091 suitable for sourcing into a shell script. This environment
1092 block will be passed to all processes the manager
1097 <term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>
1100 <para>Set one or more systemd manager environment variables,
1101 as specified on the command line.</para>
1105 <term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>
1108 <para>Unset one or more systemd manager environment
1109 variables. If only a variable name is specified it will be
1110 removed regardless of its value. If a variable and a value
1111 are specified the variable is only removed if it has the
1112 specified value.</para>
1116 <term><command>default</command></term>
1119 <para>Enter default mode. This is mostly equivalent to
1120 <command>isolate default.target</command>.</para>
1124 <term><command>rescue</command></term>
1127 <para>Enter rescue mode. This is mostly equivalent to
1128 <command>isolate rescue.target</command> but also prints a
1129 wall message to all users.</para>
1133 <term><command>emergency</command></term>
1136 <para>Enter emergency mode. This is mostly equivalent to
1137 <command>isolate emergency.target</command> but also prints
1138 a wall message to all users.</para>
1142 <term><command>halt</command></term>
1145 <para>Shut down and halt the system. This is mostly equivalent to
1146 <command>start halt.target --irreversible</command> but also
1147 prints a wall message to all users. If combined with
1148 <option>--force</option> shutdown of all running services is
1149 skipped, however all processes are killed and all file
1150 systems are unmounted or mounted read-only, immediately
1151 followed by the system halt. If <option>--force</option> is
1152 specified twice the operation is immediately executed
1153 without terminating any processes or unmounting any file
1154 systems. This may result in data loss.</para>
1158 <term><command>poweroff</command></term>
1161 <para>Shut down and power-off the system. This is mostly
1162 equivalent to <command>start poweroff.target --irreversible</command>
1163 but also prints a wall message to all users. If combined with
1164 <option>--force</option> shutdown of all running services is
1165 skipped, however all processes are killed and all file
1166 systems are unmounted or mounted read-only, immediately
1167 followed by the powering off. If <option>--force</option> is
1168 specified twice the operation is immediately executed
1169 without terminating any processes or unmounting any file
1170 systems. This may result in data loss.</para>
1174 <term><command>reboot</command></term>
1177 <para>Shut down and reboot the system. This is mostly
1178 equivalent to <command>start reboot.target --irreversible</command>
1179 but also prints a wall message to all users. If combined with
1180 <option>--force</option> shutdown of all running services is
1181 skipped, however all processes are killed and all file
1182 systems are unmounted or mounted read-only, immediately
1183 followed by the reboot. If <option>--force</option> is
1184 specified twice the operation is immediately executed
1185 without terminating any processes or unmounting any file
1186 systems. This may result in data loss.</para>
1190 <term><command>kexec</command></term>
1193 <para>Shut down and reboot the system via kexec. This is
1194 mostly equivalent to <command>start kexec.target --irreversible</command>
1195 but also prints a wall message to all users. If combined
1196 with <option>--force</option> shutdown of all running
1197 services is skipped, however all processes are killed and
1198 all file systems are unmounted or mounted read-only,
1199 immediately followed by the reboot.</para>
1203 <term><command>exit</command></term>
1206 <para>Ask the systemd manager to quit. This is only
1207 supported for user service managers (i.e. in conjunction
1208 with the <option>--user</option> option) and will fail
1214 <term><command>suspend</command></term>
1217 <para>Suspend the system. This will trigger activation of
1218 the special <filename>suspend.target</filename> target.
1223 <term><command>hibernate</command></term>
1226 <para>Hibernate the system. This will trigger activation of
1227 the special <filename>hibernate.target</filename> target.
1232 <term><command>hybrid-sleep</command></term>
1235 <para>Hibernate and suspend the system. This will trigger
1236 activation of the special
1237 <filename>hybrid-sleep.target</filename> target.</para>
1241 <term><command>switch-root <replaceable>ROOT</replaceable> [<replaceable>INIT</replaceable>]</command></term>
1244 <para>Switches to a different root directory and executes a
1245 new system manager process below it. This is intended for
1246 usage in initial RAM disks ("initrd"), and will transition
1247 from the initrd's system manager process (a.k.a "init"
1248 process) to the main system manager process. Takes two
1249 arguments: the directory to make the new root directory, and
1250 the path to the new system manager binary below it to
1251 execute as PID 1. If the latter is omitted or the empty
1252 string, a systemd binary will automatically be searched for
1253 and used as init. If the system manager path is omitted or
1254 equal to the empty string the state of the initrd's system
1255 manager process is passed to the main system manager, which
1256 allows later introspection of the state of the services
1257 involved in the initrd boot.</para>
1265 <title>Exit status</title>
1267 <para>On success 0 is returned, a non-zero failure
1268 code otherwise.</para>
1272 <title>Environment</title>
1274 <variablelist class='environment-variables'>
1276 <term><varname>$SYSTEMD_PAGER</varname></term>
1279 <para>Pager to use when <option>--no-pager</option> is not
1280 given; overrides <varname>$PAGER</varname>. Setting this to
1281 an empty string or the value <literal>cat</literal> is
1282 equivalent to passing
1283 <option>--no-pager</option>.</para>
1290 <title>See Also</title>
1292 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1293 <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1294 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1295 <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1296 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1297 <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1298 <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1299 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>