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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-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 or before
163 with <command>list-dependencies</command>, respectively.
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>-l</option></term>
179 <term><option>--full</option></term>
182 <para>Do not ellipsize unit names, cgroup members, and
183 truncate unit descriptions in the output of
184 <command>list-units</command> and
185 <command>list-jobs</command>.</para>
190 <term><option>--fail</option></term>
193 <para>If the requested operation conflicts with a pending
194 unfinished job, fail the command. If this is not specified,
195 the requested operation will replace the pending job, if
196 necessary. Do not confuse with
197 <option>--failed</option>.</para>
202 <term><option>--show-types</option></term>
205 <para>When showing sockets, show the type of the socket.</para>
210 <term><option>--irreversible</option></term>
213 <para>Mark this transaction's jobs as irreversible. This prevents
214 future conflicting transactions from replacing these jobs.
215 The jobs can still be cancelled using the <command>cancel</command>
221 <term><option>--ignore-dependencies</option></term>
224 <para>When enqueuing a new job, ignore all its dependencies
225 and execute it immediately. If passed, no required units of
226 the unit passed will be pulled in, and no ordering
227 dependencies will be honored. This is mostly a debugging and
228 rescue tool for the administrator and should not be used by
234 <term><option>-i</option></term>
235 <term><option>--ignore-inhibitors</option></term>
238 <para>When system shutdown or a sleep state is requested,
239 ignore inhibitor locks. Applications can establish inhibitor
240 locks to avoid that certain important operations (such as CD
241 burning or suchlike) are interrupted by system shutdown or a
242 sleep state. Any user may take these locks and privileged
243 users may override these locks. If any locks are taken,
244 shutdown and sleep state requests will normally fail
245 (regardless if privileged or not) and a list of active locks
246 is printed. However, if <option>--ignore-inhibitors</option>
247 is specified, the locks are ignored and not printed, and the
248 operation attempted anyway, possibly requiring additional
254 <term><option>-q</option></term>
255 <term><option>--quiet</option></term>
258 <para>Suppress output to standard output in
259 <command>snapshot</command>,
260 <command>is-active</command>,
261 <command>is-failed</command>,
262 <command>enable</command> and
263 <command>disable</command>.</para>
268 <term><option>--no-block</option></term>
271 <para>Do not synchronously wait for the requested operation
272 to finish. If this is not specified, the job will be
273 verified, enqueued and <command>systemctl</command> will
274 wait until it is completed. By passing this argument, it is
275 only verified and enqueued.</para>
280 <term><option>--no-legend</option></term>
283 <para>Do not print a legend, i.e. the column headers and
284 the footer with hints.</para>
289 <term><option>--no-pager</option></term>
292 <para>Do not pipe output into a pager.</para>
297 <term><option>--system</option></term>
300 <para>Talk to the systemd system manager. (Default)</para>
305 <term><option>--user</option></term>
308 <para>Talk to the systemd manager of the calling
314 <term><option>--no-wall</option></term>
317 <para>Do not send wall message before halt, power-off,
323 <term><option>--global</option></term>
326 <para>When used with <command>enable</command> and
327 <command>disable</command>, operate on the global user
328 configuration directory, thus enabling or disabling a unit
329 file globally for all future logins of all users.</para>
334 <term><option>--no-reload</option></term>
337 <para>When used with <command>enable</command> and
338 <command>disable</command>, do not implicitly reload daemon
339 configuration after executing the changes.</para>
344 <term><option>--no-ask-password</option></term>
347 <para>When used with <command>start</command> and related
348 commands, disables asking for passwords. Background services
349 may require input of a password or passphrase string, for
350 example to unlock system hard disks or cryptographic
351 certificates. Unless this option is specified and the
352 command is invoked from a terminal,
353 <command>systemctl</command> will query the user on the
354 terminal for the necessary secrets. Use this option to
355 switch this behavior off. In this case, the password must be
356 supplied by some other means (for example graphical password
357 agents) or the service might fail. This also disables
358 querying the user for authentication for privileged
365 <term><option>--kill-who=</option></term>
368 <para>When used with <command>kill</command>, choose which
369 processes to kill. Must be one of <option>main</option>,
370 <option>control</option> or <option>all</option> to select
371 whether to kill only the main process of the unit, the
372 control process or all processes of the unit. If omitted,
373 defaults to <option>all</option>.</para>
379 <term><option>-s</option></term>
380 <term><option>--signal=</option></term>
383 <para>When used with <command>kill</command>, choose which
384 signal to send to selected processes. Must be one of the
385 well known signal specifiers such as <constant>SIGTERM</constant>, <constant>SIGINT</constant> or
386 <constant>SIGSTOP</constant>. If omitted, defaults to
387 <option>SIGTERM</option>.</para>
392 <term><option>-f</option></term>
393 <term><option>--force</option></term>
396 <para>When used with <command>enable</command>, overwrite
397 any existing conflicting symlinks.</para>
399 <para>When used with <command>halt</command>,
400 <command>poweroff</command>, <command>reboot</command> or
401 <command>kexec</command>, execute the selected operation
402 without shutting down all units. However, all processes will
403 be killed forcibly and all file systems are unmounted or
404 remounted read-only. This is hence a drastic but relatively
405 safe option to request an immediate reboot. If
406 <option>--force</option> is specified twice for these
407 operations, they will be executed immediately without
408 terminating any processes or umounting any file
409 systems. Warning: specifying <option>--force</option> twice
410 with any of these operations might result in data
416 <term><option>--root=</option></term>
420 <command>enable</command>/<command>disable</command>/<command>is-enabled</command>
421 (and related commands), use alternative root path when
422 looking for unit files.</para>
428 <term><option>--runtime</option></term>
431 <para>When used with <command>enable</command>,
432 <command>disable</command>, <command>is-enabled</command>
433 (and related commands), make changes only temporarily, so
434 that they are lost on the next reboot. This will have the
435 effect that changes are not made in subdirectories of
436 <filename>/etc</filename> but in <filename>/run</filename>,
437 with identical immediate effects, however, since the latter
438 is lost on reboot, the changes are lost too.</para>
440 <para>Similar, when used with
441 <command>set-cgroup-attr</command>,
442 <command>unset-cgroup-attr</command>,
443 <command>set-cgroup</command> and
444 <command>unset-cgroup</command>, make changes only
445 temporarily, so that they are lost on the next
451 <term><option>-H</option></term>
452 <term><option>--host</option></term>
455 <para>Execute operation remotely. Specify a hostname, or
456 username and hostname separated by <literal>@</literal>, to connect to. This
457 will use SSH to talk to the remote systemd
463 <term><option>-P</option></term>
464 <term><option>--privileged</option></term>
467 <para>Acquire privileges via PolicyKit before executing the
473 <term><option>-n</option></term>
474 <term><option>--lines=</option></term>
477 <para>When used with <command>status</command>, controls the
478 number of journal lines to show, counting from the most
479 recent ones. Takes a positive integer argument. Defaults to
485 <term><option>-o</option></term>
486 <term><option>--output=</option></term>
489 <para>When used with <command>status</command>, controls the
490 formatting of the journal entries that are shown. For the
491 available choices, see
492 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
493 Defaults to <literal>short</literal>.</para>
498 <term><option>--plain</option></term>
501 <para>When used with <command>list-dependencies</command>,
502 the output is printed as a list instead of a tree.</para>
510 <title>Commands</title>
512 <para>The following commands are understood:</para>
516 <term><command>list-units</command></term>
519 <para>List known units (subject to limitations specified
520 with <option>-t</option>).</para>
522 <para>This is the default command.</para>
527 <term><command>list-sockets</command></term>
530 <para>List socket units ordered by the listening address. Produces output
533 LISTEN UNIT ACTIVATES
534 /dev/initctl systemd-initctl.socket systemd-initctl.service
536 [::]:22 sshd.socket sshd.service
537 kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
541 Note: because the addresses might contains spaces, this output
542 is not suitable for programmatic consumption.
545 <para>See also the options <option>--show-types</option>,
546 <option>--all</option>, and <option>--failed</option>.</para>
551 <term><command>set-log-level <replaceable>LEVEL</replaceable></command></term>
554 <para>Change current log level of the
555 <command>systemd</command> daemon to
556 <replaceable>LEVEL</replaceable> (accepts the same values
557 as <option>--log-level=</option> described in
558 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>).
564 <term><command>start <replaceable>NAME</replaceable>...</command></term>
567 <para>Start (activate) one or more units specified on the
572 <term><command>stop <replaceable>NAME</replaceable>...</command></term>
575 <para>Stop (deactivate) one or more units specified on the
580 <term><command>reload <replaceable>NAME</replaceable>...</command></term>
583 <para>Asks all units listed on the command line to reload
584 their configuration. Note that this will reload the
585 service-specific configuration, not the unit configuration
586 file of systemd. If you want systemd to reload the
587 configuration file of a unit use the
588 <command>daemon-reload</command> command. In other words:
589 for the example case of Apache, this will reload Apache's
590 <filename>httpd.conf</filename> in the web server, not the
591 <filename>apache.service</filename> systemd unit
594 <para>This command should not be confused with the
595 <command>daemon-reload</command> or <command>load</command>
601 <term><command>restart <replaceable>NAME</replaceable>...</command></term>
604 <para>Restart one or more units specified on the command
605 line. If the units are not running yet, they will be
610 <term><command>try-restart <replaceable>NAME</replaceable>...</command></term>
613 <para>Restart one or more units specified on the command
614 line if the units are running. This does nothing if units are not
615 running. Note that, for compatibility with Red Hat init
616 scripts, <command>condrestart</command> is equivalent to this
621 <term><command>reload-or-restart <replaceable>NAME</replaceable>...</command></term>
624 <para>Reload one or more units if they support it. If not,
625 restart them instead. If the units are not running yet, they
626 will be started.</para>
630 <term><command>reload-or-try-restart <replaceable>NAME</replaceable>...</command></term>
633 <para>Reload one or more units if they support it. If not,
634 restart them instead. This does nothing if the units are not
635 running. Note that, for compatibility with SysV init scripts,
636 <command>force-reload</command> is equivalent to this
641 <term><command>isolate <replaceable>NAME</replaceable></command></term>
644 <para>Start the unit specified on the command line and its
645 dependencies and stop all others.</para>
647 <para>This is similar to changing the runlevel in a
648 traditional init system. The <command>isolate</command>
649 command will immediately stop processes that are not enabled
650 in the new unit, possibly including the graphical
651 environment or terminal you are currently using.</para>
653 <para>Note that this is allowed only on units where
654 <option>AllowIsolate=</option> is enabled. See
655 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
660 <term><command>kill <replaceable>NAME</replaceable>...</command></term>
663 <para>Send a signal to one or more processes of the
664 unit. Use <option>--kill-who=</option> to select which
665 process to kill. Use <option>--kill-mode=</option> to select
666 the kill mode and <option>--signal=</option> to select the
667 signal to send.</para>
671 <term><command>is-active <replaceable>NAME</replaceable>...</command></term>
674 <para>Check whether any of the specified units are active
675 (i.e. running). Returns an exit code 0 if at least one is
676 active, non-zero otherwise. Unless <option>--quiet</option>
677 is specified, this will also print the current unit state to
682 <term><command>is-failed <replaceable>NAME</replaceable>...</command></term>
685 <para>Check whether any of the specified units are in a "failed" state.
686 Returns an exit code 0 if at least one has failed, non-zero
687 otherwise. Unless <option>--quiet</option> is specified, this
688 will also print the current unit state to
693 <term><command>status [<replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...]</command></term>
696 <para>Show terse runtime status information about one or
697 more units, followed by most recent log data from the
698 journal. If no units are specified, show all units (subject
699 to limitations specified with <option>-t</option>). If a PID
700 is passed, show information about the unit the process
703 <para>This function is intended to generate human-readable
704 output. If you are looking for computer-parsable output, use
705 <command>show</command> instead.</para>
709 <term><command>show [<replaceable>NAME</replaceable>...|<replaceable>JOB</replaceable>...]</command></term>
712 <para>Show properties of one or more units, jobs, or the
713 manager itself. If no argument is specified properties of
714 the manager will be shown. If a unit name is specified
715 properties of the unit is shown, and if a job id is
716 specified properties of the job is shown. By default, empty
717 properties are suppressed. Use <option>--all</option> to
718 show those too. To select specific properties to show use
719 <option>--property=</option>. This command is intended to be
720 used whenever computer-parsable output is required. Use
721 <command>status</command> if you are looking for formatted
722 human-readable output.</para>
727 <term><command>get-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable>...</command></term>
730 <para>Retrieve the specified control group attributes of the
731 specified unit. Takes a unit name and one or more attribute
732 names such as <literal>cpu.shares</literal>. This will
733 output the current values of the specified attributes,
734 separated by new-lines. For attributes that take a list of
735 items, the output will be newline-separated, too. This
736 operation will always try to retrieve the data in question
737 from the kernel first, and if that is not available, use the
738 configured values instead. Instead of low-level control
739 group attribute names, high-level pretty names may be used,
740 as used for unit execution environment configuration, see
741 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
742 for details. For example, passing
743 <literal>memory.limit_in_bytes</literal> and
744 <literal>MemoryLimit</literal> is equivalent.</para>
749 <term><command>set-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable> <replaceable>VALUE</replaceable>...</command></term>
752 <para>Set the specified control group attribute of the
753 specified unit to the specified value. Takes a unit
754 name and an attribute name such as
755 <literal>cpu.shares</literal>, plus one or more values
756 (multiple values may only be used for attributes that take
757 multiple values). This operation will immediately update the
758 kernel attribute for this unit and persistently store this
759 setting for later reboots (unless <option>--runtime</option>
760 is passed, in which case the setting is not saved
761 persistently and only valid until the next reboot.) Instead
762 of low-level control group attribute names, high-level pretty
763 names may be used, as used for unit execution environment
765 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
766 for details. For example, passing
767 <literal>memory.limit_in_bytes</literal> and
768 <literal>MemoryLimit</literal> is equivalent. This operation
769 will implicitly create a control group for the unit in the
770 controller the attribute belongs to, if needed. For
771 attributes that take multiple values, this operation will
772 append the specified values to the previously set values
773 list (use <command>unset-cgroup-attr</command> to reset the
774 list explicitly). For attributes that take a single value
775 only, the list will be reset implicitly.</para>
780 <term><command>unset-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable>...</command></term>
782 <listitem><para>Unset the specified control group attributes
783 of the specified unit. Takes a unit name and one or more
784 attribut names such as <literal>cpu.shares</literal>. This
785 operation might or might not have an immediate effect on the
786 current kernel attribute value. This will remove any
787 persistently stored configuration values for this attribute
788 (as set with <command>set-cgroup-attr</command> before),
789 unless <option>--runtime</option> is passed, in which case the
790 configuration is reset only until the next reboot. Again,
791 high-level control group attributes may be used instead of the
792 low-level kernel ones. For attributes which take multiple
793 values, all currently set values are reset.</para>
798 <term><command>set-cgroup <replaceable>NAME</replaceable> <replaceable>CGROUP</replaceable>...</command></term>
799 <term><command>unset-cgroup <replaceable>NAME</replaceable> <replaceable>CGROUP</replaceable>...</command></term>
801 <listitem><para>Add or remove a unit to/from a specific
802 control group hierarchy and/or control group path. Takes a
803 unit name, plus a control group specification in the syntax
804 <replaceable>CONTROLLER</replaceable>:<replaceable>PATH</replaceable>
805 or <replaceable>CONTROLLER</replaceable>. In the latter syntax
806 (where the path is omitted), the default unit control group
807 path is implied. Examples: <literal>cpu</literal> or
808 <literal>cpu:/foo/bar</literal>. If a unit is removed from a
809 control group hierarchy, all its processes will be moved to the
810 root group of the hierarchy and all control group attributes
811 will be reset. These operations are immediately reflected in
812 the kernel hierarchy, and stored persistently to disk (unless
813 <option>--runtime</option> is passed).</para>
818 <term><command>help <replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...</command></term>
821 <para>Show manual pages for one or more units, if
822 available. If a PID is given, the manual pages for the unit
823 the process belongs to are shown.</para>
828 <term><command>reset-failed [<replaceable>NAME</replaceable>...]</command></term>
831 <para>Reset the <literal>failed</literal> state of the
832 specified units, or if no unit name is passed, reset the state of all
833 units. When a unit fails in some way (i.e. process exiting
834 with non-zero error code, terminating abnormally or timing
835 out), it will automatically enter the
836 <literal>failed</literal> state and its exit code and status
837 is recorded for introspection by the administrator until the
838 service is restarted or reset with this command.</para>
843 <term><command>list-unit-files</command></term>
846 <para>List installed unit files.</para>
851 <term><command>enable <replaceable>NAME</replaceable>...</command></term>
854 <para>Enable one or more unit files or unit file instances,
855 as specified on the command line. This will create a number
856 of symlinks as encoded in the <literal>[Install]</literal>
857 sections of the unit files. After the symlinks have been
858 created, the systemd configuration is reloaded (in a way that
859 is equivalent to <command>daemon-reload</command>) to ensure
860 the changes are taken into account immediately. Note that
861 this does <emphasis>not</emphasis> have the effect of also
862 starting any of the units being enabled. If this
863 is desired, a separate <command>start</command> command must
864 be invoked for the unit. Also note that in case of instance
865 enablement, symlinks named the same as instances are created in
866 the install location, however they all point to the same
867 template unit file.</para>
869 <para>This command will print the actions executed. This
870 output may be suppressed by passing <option>--quiet</option>.
873 <para>Note that this operation creates only the suggested
874 symlinks for the units. While this command is the
875 recommended way to manipulate the unit configuration
876 directory, the administrator is free to make additional
877 changes manually by placing or removing symlinks in the
878 directory. This is particularly useful to create
879 configurations that deviate from the suggested default
880 installation. In this case, the administrator must make sure
881 to invoke <command>daemon-reload</command> manually as
882 necessary to ensure the changes are taken into account.
885 <para>Enabling units should not be confused with starting
886 (activating) units, as done by the <command>start</command>
887 command. Enabling and starting units is orthogonal: units
888 may be enabled without being started and started without
889 being enabled. Enabling simply hooks the unit into various
890 suggested places (for example, so that the unit is
891 automatically started on boot or when a particular kind of
892 hardware is plugged in). Starting actually spawns the daemon
893 process (in case of service units), or binds the socket (in
894 case of socket units), and so on.</para>
896 <para>Depending on whether <option>--system</option>,
897 <option>--user</option> or <option>--global</option> is
898 specified, this enables the unit for the system, for the
899 calling user only or for all future logins of all
900 users. Note that in the last case, no systemd daemon
901 configuration is reloaded.</para>
906 <term><command>disable <replaceable>NAME</replaceable>...</command></term>
909 <para>Disables one or more units. This removes all symlinks
910 to the specified unit files from the unit configuration
911 directory, and hence undoes the changes made by
912 <command>enable</command>. Note however that this removes
913 all symlinks to the unit files (i.e. including manual
914 additions), not just those actually created by
915 <command>enable</command>. This call implicitly reloads the
916 systemd daemon configuration after completing the disabling
917 of the units. Note that this command does not implicitly
918 stop the units that are being disabled. If this is desired,
919 an additional <command>stop</command> command should be
920 executed afterwards.</para>
922 <para>This command will print the actions executed. This
923 output may be suppressed by passing <option>--quiet</option>.
926 <para>This command honors <option>--system</option>,
927 <option>--user</option>, <option>--global</option> in a
928 similar way as <command>enable</command>.</para>
933 <term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>
936 <para>Checks whether any of the specified unit files are
937 enabled (as with <command>enable</command>). Returns an exit
938 code of 0 if at least one is enabled, non-zero
939 otherwise. Prints the current enable status. To suppress
940 this output, use <option>--quiet</option>.</para>
945 <term><command>reenable <replaceable>NAME</replaceable>...</command></term>
948 <para>Reenable one or more unit files, as specified on the
949 command line. This is a combination of
950 <command>disable</command> and <command>enable</command> and
951 is useful to reset the symlinks a unit is enabled with to
952 the defaults configured in the <literal>[Install]</literal>
953 section of the unit file.</para>
958 <term><command>preset <replaceable>NAME</replaceable>...</command></term>
961 <para>Reset one or more unit files, as specified on the
962 command line, to the defaults configured in the preset
963 policy files. This has the same effect as
964 <command>disable</command> or <command>enable</command>,
965 depending how the unit is listed in the preset files. For
966 more information on the preset policy format, see
967 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
968 For more information on the concept of presets, please
970 <ulink url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
976 <term><command>mask <replaceable>NAME</replaceable>...</command></term>
979 <para>Mask one or more unit files, as specified on the
980 command line. This will link these units to
981 <filename>/dev/null</filename>, making it impossible to
982 start them. This is a stronger version of
983 <command>disable</command>, since it prohibits all kinds of
984 activation of the unit, including manual activation. Use
985 this option with care.</para>
990 <term><command>unmask <replaceable>NAME</replaceable>...</command></term>
993 <para>Unmask one or more unit files, as specified on the
994 command line. This will undo the effect of
995 <command>mask</command>.</para>
1000 <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
1003 <para>Link a unit file that is not in the unit file search
1004 paths into the unit file search path. This requires an
1005 absolute path to a unit file. The effect of this can be
1006 undone with <command>disable</command>. The effect of this
1007 command is that a unit file is available for
1008 <command>start</command> and other commands although it
1009 is not installed directly in the unit search path.</para>
1014 <term><command>get-default</command></term>
1017 <para>Get the default target specified
1018 via <filename>default.target</filename> link.</para>
1023 <term><command>set-default <replaceable>NAME</replaceable></command></term>
1026 <para>Set the default target to boot into. Command links
1027 <filename>default.target</filename> to the given unit.</para>
1032 <term><command>load <replaceable>NAME</replaceable>...</command></term>
1035 <para>Load one or more units specified on the command
1036 line. This will simply load their configuration from disk,
1037 but not start them. To start them, you need to use the
1038 <command>start</command> command which will implicitly load
1039 a unit that has not been loaded yet. Note that systemd
1040 garbage collects loaded units that are not active or
1041 referenced by an active unit. This means that units loaded
1042 this way will usually not stay loaded for long. Also note
1043 that this command cannot be used to reload unit
1044 configuration. Use the <command>daemon-reload</command>
1045 command for that. All in all, this command is of little use
1046 except for debugging.</para>
1048 <para>This command should not be confused with the
1049 <command>daemon-reload</command> or
1050 <command>reload</command>.</para>
1054 <term><command>list-jobs</command></term>
1057 <para>List jobs that are in progress.</para>
1061 <term><command>cancel <replaceable>JOB</replaceable>...</command></term>
1064 <para>Cancel one or more jobs specified on the command line
1065 by their numeric job IDs. If no job ID is specified, cancel
1066 all pending jobs.</para>
1070 <term><command>dump</command></term>
1073 <para>Dump server status. This will output a (usually very
1074 long) human readable manager status dump. Its format is
1075 subject to change without notice and should not be parsed by
1076 applications.</para>
1080 <term><command>list-dependencies <replaceable>NAME</replaceable></command></term>
1083 <para>Shows required and wanted units of the specified
1084 unit. If no unit is specified,
1085 <filename>default.target</filename> is implied. Target units
1086 are recursively expanded. When <option>--all</option> is
1087 passed, all other units are recursively expanded as
1092 <term><command>snapshot [<replaceable>NAME</replaceable>]</command></term>
1095 <para>Create a snapshot. If a snapshot name is specified,
1096 the new snapshot will be named after it. If none is
1097 specified, an automatic snapshot name is generated. In either
1098 case, the snapshot name used is printed to STDOUT, unless
1099 <option>--quiet</option> is specified.</para>
1101 <para>A snapshot refers to a saved state of the systemd
1102 manager. It is implemented itself as a unit that is
1103 generated dynamically with this command and has dependencies
1104 on all units active at the time. At a later time, the user
1105 may return to this state by using the
1106 <command>isolate</command> command on the snapshot unit.
1109 <para>Snapshots are only useful for saving and restoring
1110 which units are running or are stopped, they do not
1111 save/restore any other state. Snapshots are dynamic and lost
1116 <term><command>delete <replaceable>NAME</replaceable>...</command></term>
1119 <para>Remove a snapshot previously created with
1120 <command>snapshot</command>.</para>
1124 <term><command>daemon-reload</command></term>
1127 <para>Reload systemd manager configuration. This will reload
1128 all unit files and recreate the entire dependency
1129 tree. While the daemon is reloaded, all sockets systemd
1130 listens on on behalf of user configuration will stay
1131 accessible.</para> <para>This command should not be confused
1132 with the <command>load</command> or
1133 <command>reload</command> commands.</para>
1137 <term><command>daemon-reexec</command></term>
1140 <para>Reexecute the systemd manager. This will serialize the
1141 manager state, reexecute the process and deserialize the
1142 state again. This command is of little use except for
1143 debugging and package upgrades. Sometimes it might be
1144 helpful as a heavy-weight <command>daemon-reload</command>.
1145 While the daemon is reexecuted, all sockets systemd listening
1146 on behalf of user configuration will stay accessible.
1151 <term><command>show-environment</command></term>
1154 <para>Dump the systemd manager environment block. The
1155 environment block will be dumped in straight-forward form
1156 suitable for sourcing into a shell script. This environment
1157 block will be passed to all processes the manager
1162 <term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>
1165 <para>Set one or more systemd manager environment variables,
1166 as specified on the command line.</para>
1170 <term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>
1173 <para>Unset one or more systemd manager environment
1174 variables. If only a variable name is specified, it will be
1175 removed regardless of its value. If a variable and a value
1176 are specified, the variable is only removed if it has the
1177 specified value.</para>
1181 <term><command>default</command></term>
1184 <para>Enter default mode. This is mostly equivalent to
1185 <command>isolate default.target</command>.</para>
1189 <term><command>rescue</command></term>
1192 <para>Enter rescue mode. This is mostly equivalent to
1193 <command>isolate rescue.target</command>, but also prints a
1194 wall message to all users.</para>
1198 <term><command>emergency</command></term>
1201 <para>Enter emergency mode. This is mostly equivalent to
1202 <command>isolate emergency.target</command>, but also prints
1203 a wall message to all users.</para>
1207 <term><command>halt</command></term>
1210 <para>Shut down and halt the system. This is mostly equivalent to
1211 <command>start halt.target --irreversible</command>, but also
1212 prints a wall message to all users. If combined with
1213 <option>--force</option>, shutdown of all running services is
1214 skipped, however all processes are killed and all file
1215 systems are unmounted or mounted read-only, immediately
1216 followed by the system halt. If <option>--force</option> is
1217 specified twice, the operation is immediately executed
1218 without terminating any processes or unmounting any file
1219 systems. This may result in data loss.</para>
1223 <term><command>poweroff</command></term>
1226 <para>Shut down and power-off the system. This is mostly
1227 equivalent to <command>start poweroff.target --irreversible</command>,
1228 but also prints a wall message to all users. If combined with
1229 <option>--force</option>, shutdown of all running services is
1230 skipped, however all processes are killed and all file
1231 systems are unmounted or mounted read-only, immediately
1232 followed by the powering off. If <option>--force</option> is
1233 specified twice, the operation is immediately executed
1234 without terminating any processes or unmounting any file
1235 systems. This may result in data loss.</para>
1239 <term><command>reboot</command></term>
1242 <para>Shut down and reboot the system. This is mostly
1243 equivalent to <command>start reboot.target --irreversible</command>,
1244 but also prints a wall message to all users. If combined with
1245 <option>--force</option>, shutdown of all running services is
1246 skipped, however all processes are killed and all file
1247 systems are unmounted or mounted read-only, immediately
1248 followed by the reboot. If <option>--force</option> is
1249 specified twice, the operation is immediately executed
1250 without terminating any processes or unmounting any file
1251 systems. This may result in data loss.</para>
1255 <term><command>kexec</command></term>
1258 <para>Shut down and reboot the system via kexec. This is
1259 mostly equivalent to <command>start kexec.target --irreversible</command>,
1260 but also prints a wall message to all users. If combined
1261 with <option>--force</option>, shutdown of all running
1262 services is skipped, however all processes are killed and
1263 all file systems are unmounted or mounted read-only,
1264 immediately followed by the reboot.</para>
1268 <term><command>exit</command></term>
1271 <para>Ask the systemd manager to quit. This is only
1272 supported for user service managers (i.e. in conjunction
1273 with the <option>--user</option> option) and will fail
1279 <term><command>suspend</command></term>
1282 <para>Suspend the system. This will trigger activation of
1283 the special <filename>suspend.target</filename> target.
1288 <term><command>hibernate</command></term>
1291 <para>Hibernate the system. This will trigger activation of
1292 the special <filename>hibernate.target</filename> target.
1297 <term><command>hybrid-sleep</command></term>
1300 <para>Hibernate and suspend the system. This will trigger
1301 activation of the special
1302 <filename>hybrid-sleep.target</filename> target.</para>
1306 <term><command>switch-root <replaceable>ROOT</replaceable> [<replaceable>INIT</replaceable>]</command></term>
1309 <para>Switches to a different root directory and executes a
1310 new system manager process below it. This is intended for
1311 usage in initial RAM disks ("initrd"), and will transition
1312 from the initrd's system manager process (a.k.a "init"
1313 process) to the main system manager process. This call takes two
1314 arguments: the directory that is to become the new root directory, and
1315 the path to the new system manager binary below it to
1316 execute as PID 1. If the latter is omitted or the empty
1317 string, a systemd binary will automatically be searched for
1318 and used as init. If the system manager path is omitted or
1319 equal to the empty string, the state of the initrd's system
1320 manager process is passed to the main system manager, which
1321 allows later introspection of the state of the services
1322 involved in the initrd boot.</para>
1330 <title>Exit status</title>
1332 <para>On success, 0 is returned, a non-zero failure
1333 code otherwise.</para>
1337 <title>Environment</title>
1339 <variablelist class='environment-variables'>
1341 <term><varname>$SYSTEMD_PAGER</varname></term>
1344 <para>Pager to use when <option>--no-pager</option> is not
1345 given; overrides <varname>$PAGER</varname>. Setting this to
1346 an empty string or the value <literal>cat</literal> is
1347 equivalent to passing
1348 <option>--no-pager</option>.</para>
1355 <title>See Also</title>
1357 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1358 <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1359 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1360 <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1361 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1362 <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1363 <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1364 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>