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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>--irreversible</option></term>
179 <para>Mark this transaction's jobs as irreversible. This prevents
180 future conflicting transactions from replacing these jobs.
181 The jobs can still be cancelled using the <command>cancel</command>
187 <term><option>--ignore-dependencies</option></term>
190 <para>When enqueuing a new job ignore all its dependencies
191 and execute it immediately. If passed no required units of
192 the unit passed will be pulled in, and no ordering
193 dependencies will be honored. This is mostly a debugging and
194 rescue tool for the administrator and should not be used by
200 <term><option>-i</option></term>
201 <term><option>--ignore-inhibitors</option></term>
204 <para>When system shutdown or a sleep state is requested,
205 ignore inhibitor locks. Applications can establish inhibitor
206 locks to avoid that certain important operations (such as CD
207 burning or suchlike) are interrupted by system shutdown or a
208 sleep state. Any user may take these locks and privileged
209 users may override these locks. If any locks are taken,
210 shutdown and sleep state requests will normally fail
211 (regardless if privileged or not) and a list of active locks
212 is printed. However if <option>--ignore-inhibitors</option>
213 is specified the locks are ignored and not printed, and the
214 operation attempted anyway, possibly requiring additional
220 <term><option>-q</option></term>
221 <term><option>--quiet</option></term>
224 <para>Suppress output to standard output in
225 <command>snapshot</command>,
226 <command>is-active</command>,
227 <command>is-failed</command>,
228 <command>enable</command> and
229 <command>disable</command>.</para>
234 <term><option>--no-block</option></term>
237 <para>Do not synchronously wait for the requested operation
238 to finish. If this is not specified the job will be
239 verified, enqueued and <command>systemctl</command> will
240 wait until it is completed. By passing this argument it is
241 only verified and enqueued.</para>
246 <term><option>--no-legend</option></term>
249 <para>Do not print a legend, i.e. the column headers and
250 the footer with hints.</para>
255 <term><option>--no-pager</option></term>
258 <para>Do not pipe output into a pager.</para>
263 <term><option>--system</option></term>
266 <para>Talk to the systemd system manager. (Default)</para>
271 <term><option>--user</option></term>
274 <para>Talk to the systemd manager of the calling
280 <term><option>--no-wall</option></term>
283 <para>Don't send wall message before halt, power-off,
289 <term><option>--global</option></term>
292 <para>When used with <command>enable</command> and
293 <command>disable</command>, operate on the global user
294 configuration directory, thus enabling or disabling a unit
295 file globally for all future logins of all users.</para>
300 <term><option>--no-reload</option></term>
303 <para>When used with <command>enable</command> and
304 <command>disable</command>, do not implicitly reload daemon
305 configuration after executing the changes.</para>
310 <term><option>--no-ask-password</option></term>
313 <para>When used with <command>start</command> and related
314 commands, disables asking for passwords. Background services
315 may require input of a password or passphrase string, for
316 example to unlock system hard disks or cryptographic
317 certificates. Unless this option is specified and the
318 command is invoked from a terminal
319 <command>systemctl</command> will query the user on the
320 terminal for the necessary secrets. Use this option to
321 switch this behavior off. In this case the password must be
322 supplied by some other means (for example graphical password
323 agents) or the service might fail. This also disables
324 querying the user for authentication for privileged
331 <term><option>--kill-who=</option></term>
334 <para>When used with <command>kill</command>, choose which
335 processes to kill. Must be one of <option>main</option>,
336 <option>control</option> or <option>all</option> to select
337 whether to kill only the main process of the unit, the
338 control process or all processes of the unit. If omitted
339 defaults to <option>all</option>.</para>
345 <term><option>-s</option></term>
346 <term><option>--signal=</option></term>
349 <para>When used with <command>kill</command>, choose which
350 signal to send to selected processes. Must be one of the
351 well known signal specifiers such as SIGTERM, SIGINT or
352 SIGSTOP. If omitted defaults to
353 <option>SIGTERM</option>.</para>
358 <term><option>-f</option></term>
359 <term><option>--force</option></term>
362 <para>When used with <command>enable</command>, overwrite
363 any existing conflicting symlinks.</para>
365 <para>When used with <command>halt</command>,
366 <command>poweroff</command>, <command>reboot</command> or
367 <command>kexec</command> execute the selected operation
368 without shutting down all units. However, all processes will
369 be killed forcibly and all file systems are unmounted or
370 remounted read-only. This is hence a drastic but relatively
371 safe option to request an immediate reboot. If
372 <option>--force</option> is specified twice for these
373 operations, they will be executed immediately without
374 terminating any processes or umounting any file
375 systems. Warning: specifying <option>--force</option> twice
376 with any of these operations might result in data
382 <term><option>--root=</option></term>
386 <command>enable</command>/<command>disable</command>/<command>is-enabled</command>
387 (and related commands), use alternative root path when
388 looking for unit files.</para>
394 <term><option>--runtime</option></term>
397 <para>When used with <command>enable</command>,
398 <command>disable</command>, <command>is-enabled</command>
399 (and related commands), make changes only temporarily, so
400 that they are lost on the next reboot. This will have the
401 effect that changes are not made in subdirectories of
402 <filename>/etc</filename> but in <filename>/run</filename>,
403 with identical immediate effects, however, since the latter
404 is lost on reboot, the changes are lost too.</para>
406 <para>Similar, when used with
407 <command>set-cgroup-attr</command>,
408 <command>unset-cgroup-attr</command>,
409 <command>set-cgroup</command> and
410 <command>unset-cgroup</command>, make changes only
411 temporarily, so that they are lost on the next
417 <term><option>-H</option></term>
418 <term><option>--host</option></term>
421 <para>Execute operation remotely. Specify a hostname, or
422 username and hostname separated by @, to connect to. This
423 will use SSH to talk to the remote systemd
429 <term><option>-P</option></term>
430 <term><option>--privileged</option></term>
433 <para>Acquire privileges via PolicyKit before executing the
439 <term><option>-n</option></term>
440 <term><option>--lines=</option></term>
443 <para>When used with <command>status</command> controls the
444 number of journal lines to show, counting from the most
445 recent ones. Takes a positive integer argument. Defaults to
451 <term><option>-o</option></term>
452 <term><option>--output=</option></term>
455 <para>When used with <command>status</command> controls the
456 formatting of the journal entries that are shown. For the
457 available choices see
458 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
459 Defaults to <literal>short</literal>.</para>
467 <title>Commands</title>
469 <para>The following commands are understood:</para>
473 <term><command>list-units</command></term>
476 <para>List known units (subject to limitations specified
477 with <option>-t</option>).</para>
479 <para>This is the default command.</para>
483 <term><command>start <replaceable>NAME</replaceable>...</command></term>
486 <para>Start (activate) one or more units specified on the
491 <term><command>stop <replaceable>NAME</replaceable>...</command></term>
494 <para>Stop (deactivate) one or more units specified on the
499 <term><command>reload <replaceable>NAME</replaceable>...</command></term>
502 <para>Asks all units listed on the command line to reload
503 their configuration. Note that this will reload the
504 service-specific configuration, not the unit configuration
505 file of systemd. If you want systemd to reload the
506 configuration file of a unit use the
507 <command>daemon-reload</command> command. In other words:
508 for the example case of Apache, this will reload Apache's
509 <filename>httpd.conf</filename> in the web server, not the
510 <filename>apache.service</filename> systemd unit
513 <para>This command should not be confused with the
514 <command>daemon-reload</command> or <command>load</command>
520 <term><command>restart <replaceable>NAME</replaceable>...</command></term>
523 <para>Restart one or more units specified on the command
524 line. If the units are not running yet they will be
529 <term><command>try-restart <replaceable>NAME</replaceable>...</command></term>
532 <para>Restart one or more units specified on the command
533 line if the units are running. Do nothing if units are not
534 running. Note that for compatibility with Red Hat init
535 scripts <command>condrestart</command> is equivalent to this
540 <term><command>reload-or-restart <replaceable>NAME</replaceable>...</command></term>
543 <para>Reload one or more units if they support it. If not,
544 restart them instead. If the units are not running yet they
545 will be started.</para>
549 <term><command>reload-or-try-restart <replaceable>NAME</replaceable>...</command></term>
552 <para>Reload one or more units if they support it. If not,
553 restart them instead. Do nothing if the units are not
554 running. Note that for compatibility with SysV init scripts
555 <command>force-reload</command> is equivalent to this
560 <term><command>isolate <replaceable>NAME</replaceable></command></term>
563 <para>Start the unit specified on the command line and its
564 dependencies and stop all others.</para>
566 <para>This is similar to changing the runlevel in a
567 traditional init system. The <command>isolate</command>
568 command will immediately stop processes that are not enabled
569 in the new unit, possibly including the graphical
570 environment or terminal you are currently using.</para>
572 <para>Note that this is allowed only on units where
573 <option>AllowIsolate=</option> is enabled. See
574 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
579 <term><command>kill <replaceable>NAME</replaceable>...</command></term>
582 <para>Send a signal to one or more processes of the
583 unit. Use <option>--kill-who=</option> to select which
584 process to kill. Use <option>--kill-mode=</option> to select
585 the kill mode and <option>--signal=</option> to select the
586 signal to send.</para>
590 <term><command>is-active <replaceable>NAME</replaceable>...</command></term>
593 <para>Check whether any of the specified units are active
594 (i.e. running). Returns an exit code 0 if at least one is
595 active, non-zero otherwise. Unless <option>--quiet</option>
596 is specified this will also print the current unit state to
601 <term><command>is-failed <replaceable>NAME</replaceable>...</command></term>
604 <para>Check whether any of the specified units are failed.
605 Returns an exit code 0 if at least one is failed, non-zero
606 otherwise. Unless <option>--quiet</option> is specified this
607 will also print the current unit state to
612 <term><command>status [<replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...]</command></term>
615 <para>Show terse runtime status information about one or
616 more units, followed by most recent log data from the
617 journal. If no units are specified, show all units (subject
618 to limitations specified with <option>-t</option>). If a PID
619 is passed show information about the unit the process
622 <para>This function is intended to generate human-readable
623 output. If you are looking for computer-parsable output, use
624 <command>show</command> instead.</para>
628 <term><command>show [<replaceable>NAME</replaceable>...|<replaceable>JOB</replaceable>...]</command></term>
631 <para>Show properties of one or more units, jobs, or the
632 manager itself. If no argument is specified properties of
633 the manager will be shown. If a unit name is specified
634 properties of the unit is shown, and if a job id is
635 specified properties of the job is shown. By default, empty
636 properties are suppressed. Use <option>--all</option> to
637 show those too. To select specific properties to show use
638 <option>--property=</option>. This command is intended to be
639 used whenever computer-parsable output is required. Use
640 <command>status</command> if you are looking for formatted
641 human-readable output.</para>
646 <term><command>get-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable>...</command></term>
649 <para>Retrieve the specified control group attributes of the
650 specified unit. Takes a unit name and one or more attribute
651 names such as <literal>cpu.shares</literal>. This will
652 output the current values of the specified attributes,
653 separated by new-lines. For attributes that take list of
654 items the output will be new-line separated, too. This
655 operation will always try to retrieve the data in question
656 from the kernel first, and if that is not available use the
657 configured values instead. Instead of low-level control
658 group attribute names high-level pretty names may be used,
659 as used for unit execution environment configuration, see
660 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
661 for details. For example, passing
662 <literal>memory.limit_in_bytes</literal> and
663 <literal>MemoryLimit</literal> is equivalent.</para>
668 <term><command>set-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable> <replaceable>VALUE</replaceable>...</command></term>
671 <para>Set the specified control group attribute of the
672 specified unit to the specified value. Takes a unit
673 name and an attribute name such as
674 <literal>cpu.shares</literal>, plus one or more values
675 (multiple values may only be used for attributes that take
676 multiple values). This operation will immediately update the
677 kernel attribute for this unit and persistently store this
678 setting for later reboots (unless <option>--runtime</option>
679 is passed, in which case the setting is not saved
680 persistently and only valid until the next reboot.) Instead
681 of low-level control group attribute names high-level pretty
682 names may be used, as used for unit execution environment
684 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
685 for details. For example, passing
686 <literal>memory.limit_in_bytes</literal> and
687 <literal>MemoryLimit</literal> is equivalent. This operation
688 will implicitly create a control group for the unit in the
689 controller the attribute belongs to, if needed. For
690 attributes that take multiple values, this operation will
691 append the specified values to the previously set values
692 list (use <command>unset-cgroup-attr</command> to reset the
693 list explicitly). For attributes that take a single value
694 only the list will be reset implicitly.</para>
699 <term><command>unset-cgroup-attr <replaceable>NAME</replaceable> <replaceable>ATTRIBUTE</replaceable>...</command></term>
701 <listitem><para>Unset the specified control group attributes
702 of the specified unit. Takes a unit name and one or more
703 attribut names such as <literal>cpu.shares</literal>. This
704 operation might or might not have an immediate effect on the
705 current kernel attribute value. This will remove any
706 persistently stored configuration values for this attribute
707 (as set with <command>set-cgroup-attr</command> before),
708 unless <option>--runtime</option> is passed, in which case the
709 configuration is reset only until the next reboot. Again,
710 high-level control group attributes may be used instead of the
711 low-level kernel ones. For attributes which take multiple
712 values, all currently set values are reset.</para>
717 <term><command>set-cgroup <replaceable>NAME</replaceable> <replaceable>CGROUP</replaceable>...</command></term>
718 <term><command>unset-cgroup <replaceable>NAME</replaceable> <replaceable>CGROUP</replaceable>...</command></term>
720 <listitem><para>Add or remove a unit to/from a specific
721 control group hierarchy and/or control group path. Takes a
722 unit name, plus a control group specification in the syntax
723 <replaceable>CONTROLLER</replaceable>:<replaceable>PATH</replaceable>
724 or <replaceable>CONTROLLER</replaceable>. In the latter syntax
725 (where the path is ommitted) the default unit control group
726 path is implied. Examples: <literal>cpu</literal> or
727 <literal>cpu:/foo/bar</literal>. If a unit is removed from a
728 control group hierarchy all its processes will be moved to the
729 root group of the hierarchy and all control group attributes
730 will be reset. These operations are immediately reflected in
731 the kernel hierarchy, and stored persistently to disk (unless
732 <option>--runtime</option> is passed).</para>
737 <term><command>help <replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...</command></term>
740 <para>Show manual pages for one or more units, if
741 available. If a PID is passed the manual pages for the unit
742 the process of the PID belongs to is
748 <term><command>reset-failed [<replaceable>NAME</replaceable>...]</command></term>
751 <para>Reset the <literal>failed</literal> state of the
752 specified units, or if no unit name is passed of all
753 units. When a unit fails in some way (i.e. process exiting
754 with non-zero error code, terminating abnormally or timing
755 out) it will automatically enter the
756 <literal>failed</literal> state and its exit code and status
757 is recorded for introspection by the administrator until the
758 service is restarted or reset with this command.</para>
763 <term><command>list-unit-files</command></term>
766 <para>List installed unit files.</para>
771 <term><command>enable <replaceable>NAME</replaceable>...</command></term>
774 <para>Enable one or more unit files or unit file instances,
775 as specified on the command line. This will create a number
776 of symlinks as encoded in the <literal>[Install]</literal>
777 sections of the unit files. After the symlinks have been
778 created the systemd configuration is reloaded (in a way that
779 is equivalent to <command>daemon-reload</command>) to ensure
780 the changes are taken into account immediately. Note that
781 this does not have the effect that any of the units enabled
782 are also started at the same time. If this is desired a
783 separate <command>start</command> command must be invoked
784 for the unit. Also note that in case of instance enablement,
785 symlinks named same as instances are created in install
786 location, however they all point to the same template unit
789 <para>This command will print the actions executed. This
790 output may be suppressed by passing <option>--quiet</option>.
793 <para>Note that this operation creates only the suggested
794 symlinks for the units. While this command is the
795 recommended way to manipulate the unit configuration
796 directory, the administrator is free to make additional
797 changes manually, by placing or removing symlinks in the
798 directory. This is particularly useful to create
799 configurations that deviate from the suggested default
800 installation. In this case the administrator must make sure
801 to invoke <command>daemon-reload</command> manually as
802 necessary, to ensure his changes are taken into account.
805 <para>Enabling units should not be confused with starting
806 (activating) units, as done by the <command>start</command>
807 command. Enabling and starting units is orthogonal: units
808 may be enabled without being started and started without
809 being enabled. Enabling simply hooks the unit into various
810 suggested places (for example, so that the unit is
811 automatically started on boot or when a particular kind of
812 hardware is plugged in). Starting actually spawns the daemon
813 process (in case of service units), or binds the socket (in
814 case of socket units), and so on.</para>
816 <para>Depending on whether <option>--system</option>,
817 <option>--user</option> or <option>--global</option> is
818 specified this enables the unit for the system, for the
819 calling user only or for all future logins of all
820 users. Note that in the last case no systemd daemon
821 configuration is reloaded.</para>
826 <term><command>disable <replaceable>NAME</replaceable>...</command></term>
829 <para>Disables one or more units. This removes all symlinks
830 to the specified unit files from the unit configuration
831 directory, and hence undoes the changes made by
832 <command>enable</command>. Note however that this removes
833 all symlinks to the unit files (i.e. including manual
834 additions), not just those actually created by
835 <command>enable</command>. This call implicitly reloads the
836 systemd daemon configuration after completing the disabling
837 of the units. Note that this command does not implicitly
838 stop the units that are being disabled. If this is desired
839 an additional <command>stop</command> command should be
840 executed afterwards.</para>
842 <para>This command will print the actions executed. This
843 output may be suppressed by passing <option>--quiet</option>.
846 <para>This command honors <option>--system</option>,
847 <option>--user</option>, <option>--global</option> in a
848 similar way as <command>enable</command>.</para>
853 <term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>
856 <para>Checks whether any of the specified unit files are
857 enabled (as with <command>enable</command>). Returns an exit
858 code of 0 if at least one is enabled, non-zero
859 otherwise. Prints the current enable status. To suppress
860 this output use <option>--quiet</option>.</para>
865 <term><command>reenable <replaceable>NAME</replaceable>...</command></term>
868 <para>Reenable one or more unit files, as specified on the
869 command line. This is a combination of
870 <command>disable</command> and <command>enable</command> and
871 is useful to reset the symlinks a unit is enabled with to
872 the defaults configured in the <literal>[Install]</literal>
873 section of the unit file.</para>
878 <term><command>preset <replaceable>NAME</replaceable>...</command></term>
881 <para>Reset one or more unit files, as specified on the
882 command line, to the defaults configured in the preset
883 policy files. This has the same effect as
884 <command>disable</command> or <command>enable</command>,
885 depending how the unit is listed in the preset files. For
886 more information on preset policy format see
887 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
888 For more information on the concept of presets please
890 <ulink url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>
896 <term><command>mask <replaceable>NAME</replaceable>...</command></term>
899 <para>Mask one or more unit files, as specified on the
900 command line. This will link these units to
901 <filename>/dev/null</filename>, making it impossible to
902 start them. This is a stronger version of
903 <command>disable</command>, since it prohibits all kinds of
904 activation of the unit, including manual activation. Use
905 this option with care.</para>
910 <term><command>unmask <replaceable>NAME</replaceable>...</command></term>
913 <para>Unmask one or more unit files, as specified on the
914 command line. This will undo the effect of
915 <command>mask</command>.</para>
920 <term><command>link <replaceable>FILENAME</replaceable>...</command></term>
923 <para>Link a unit file that is not in the unit file search
924 paths into the unit file search path. This requires an
925 absolute path to a unit file. The effect of this can be
926 undone with <command>disable</command>. The effect of this
927 command is that a unit file is available for
928 <command>start</command> and other commands although it
929 isn't installed directly in the unit search path.</para>
934 <term><command>load <replaceable>NAME</replaceable>...</command></term>
937 <para>Load one or more units specified on the command
938 line. This will simply load their configuration from disk,
939 but not start them. To start them you need to use the
940 <command>start</command> command which will implicitly load
941 a unit that has not been loaded yet. Note that systemd
942 garbage collects loaded units that are not active or
943 referenced by an active unit. This means that units loaded
944 this way will usually not stay loaded for long. Also note
945 that this command cannot be used to reload unit
946 configuration. Use the <command>daemon-reload</command>
947 command for that. All in all, this command is of little use
948 except for debugging.</para>
950 <para>This command should not be confused with the
951 <command>daemon-reload</command> or
952 <command>reload</command>.</para>
956 <term><command>list-jobs</command></term>
959 <para>List jobs that are in progress.</para>
963 <term><command>cancel <replaceable>JOB</replaceable>...</command></term>
966 <para>Cancel one or more jobs specified on the command line
967 by their numeric job IDs. If no job id is specified, cancel
968 all pending jobs.</para>
972 <term><command>dump</command></term>
975 <para>Dump server status. This will output a (usually very
976 long) human readable manager status dump. Its format is
977 subject to change without notice and should not be parsed by
982 <term><command>list-dependencies <replaceable>NAME</replaceable></command></term>
985 <para>Shows required and wanted units of the specified
986 unit. If no unit is specified
987 <filename>default.target</filename> is implied. Target units
988 are recursively expanded. When <option>--all</option> is
989 passed all other units are recursively expanded as
994 <term><command>snapshot [<replaceable>NAME</replaceable>]</command></term>
997 <para>Create a snapshot. If a snapshot name is specified,
998 the new snapshot will be named after it. If none is
999 specified an automatic snapshot name is generated. In either
1000 case, the snapshot name used is printed to STDOUT, unless
1001 <option>--quiet</option> is specified.</para>
1003 <para>A snapshot refers to a saved state of the systemd
1004 manager. It is implemented itself as a unit that is
1005 generated dynamically with this command and has dependencies
1006 on all units active at the time. At a later time the user
1007 may return to this state by using the
1008 <command>isolate</command> command on the snapshot unit.
1011 <para>Snapshots are only useful for saving and restoring
1012 which units are running or are stopped, they do not
1013 save/restore any other state. Snapshots are dynamic and lost
1018 <term><command>delete <replaceable>NAME</replaceable>...</command></term>
1021 <para>Remove a snapshot previously created with
1022 <command>snapshot</command>.</para>
1026 <term><command>daemon-reload</command></term>
1029 <para>Reload systemd manager configuration. This will reload
1030 all unit files and recreate the entire dependency
1031 tree. While the daemon is reloaded, all sockets systemd
1032 listens on on behalf of user configuration will stay
1033 accessible.</para> <para>This command should not be confused
1034 with the <command>load</command> or
1035 <command>reload</command> commands.</para>
1039 <term><command>daemon-reexec</command></term>
1042 <para>Reexecute the systemd manager. This will serialize the
1043 manager state, reexecute the process and deserialize the
1044 state again. This command is of little use except for
1045 debugging and package upgrades. Sometimes it might be
1046 helpful as a heavy-weight <command>daemon-reload</command>.
1047 While the daemon is reexecuted all sockets systemd listens
1048 on on behalf of user configuration will stay accessible.
1053 <term><command>show-environment</command></term>
1056 <para>Dump the systemd manager environment block. The
1057 environment block will be dumped in straight-forward form
1058 suitable for sourcing into a shell script. This environment
1059 block will be passed to all processes the manager
1064 <term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>
1067 <para>Set one or more systemd manager environment variables,
1068 as specified on the command line.</para>
1072 <term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>
1075 <para>Unset one or more systemd manager environment
1076 variables. If only a variable name is specified it will be
1077 removed regardless of its value. If a variable and a value
1078 are specified the variable is only removed if it has the
1079 specified value.</para>
1083 <term><command>default</command></term>
1086 <para>Enter default mode. This is mostly equivalent to
1087 <command>isolate default.target</command>.</para>
1091 <term><command>rescue</command></term>
1094 <para>Enter rescue mode. This is mostly equivalent to
1095 <command>isolate rescue.target</command> but also prints a
1096 wall message to all users.</para>
1100 <term><command>emergency</command></term>
1103 <para>Enter emergency mode. This is mostly equivalent to
1104 <command>isolate emergency.target</command> but also prints
1105 a wall message to all users.</para>
1109 <term><command>halt</command></term>
1112 <para>Shut down and halt the system. This is mostly equivalent to
1113 <command>start halt.target --irreversible</command> but also
1114 prints a wall message to all users. If combined with
1115 <option>--force</option> shutdown of all running services is
1116 skipped, however all processes are killed and all file
1117 systems are unmounted or mounted read-only, immediately
1118 followed by the system halt. If <option>--force</option> is
1119 specified twice the operation is immediately executed
1120 without terminating any processes or unmounting any file
1121 systems. This may result in data loss.</para>
1125 <term><command>poweroff</command></term>
1128 <para>Shut down and power-off the system. This is mostly
1129 equivalent to <command>start poweroff.target --irreversible</command>
1130 but also prints a wall message to all users. If combined with
1131 <option>--force</option> shutdown of all running services is
1132 skipped, however all processes are killed and all file
1133 systems are unmounted or mounted read-only, immediately
1134 followed by the powering off. If <option>--force</option> is
1135 specified twice the operation is immediately executed
1136 without terminating any processes or unmounting any file
1137 systems. This may result in data loss.</para>
1141 <term><command>reboot</command></term>
1144 <para>Shut down and reboot the system. This is mostly
1145 equivalent to <command>start reboot.target --irreversible</command>
1146 but also prints a wall message to all users. If combined with
1147 <option>--force</option> shutdown of all running services is
1148 skipped, however all processes are killed and all file
1149 systems are unmounted or mounted read-only, immediately
1150 followed by the reboot. If <option>--force</option> is
1151 specified twice the operation is immediately executed
1152 without terminating any processes or unmounting any file
1153 systems. This may result in data loss.</para>
1157 <term><command>kexec</command></term>
1160 <para>Shut down and reboot the system via kexec. This is
1161 mostly equivalent to <command>start kexec.target --irreversible</command>
1162 but also prints a wall message to all users. If combined
1163 with <option>--force</option> shutdown of all running
1164 services is skipped, however all processes are killed and
1165 all file systems are unmounted or mounted read-only,
1166 immediately followed by the reboot.</para>
1170 <term><command>exit</command></term>
1173 <para>Ask the systemd manager to quit. This is only
1174 supported for user service managers (i.e. in conjunction
1175 with the <option>--user</option> option) and will fail
1181 <term><command>suspend</command></term>
1184 <para>Suspend the system. This will trigger activation of
1185 the special <filename>suspend.target</filename> target.
1190 <term><command>hibernate</command></term>
1193 <para>Hibernate the system. This will trigger activation of
1194 the special <filename>hibernate.target</filename> target.
1199 <term><command>hybrid-sleep</command></term>
1202 <para>Hibernate and suspend the system. This will trigger
1203 activation of the special
1204 <filename>hybrid-sleep.target</filename> target.</para>
1208 <term><command>switch-root <replaceable>ROOT</replaceable> [<replaceable>INIT</replaceable>]</command></term>
1211 <para>Switches to a different root directory and executes a
1212 new system manager process below it. This is intended for
1213 usage in initial RAM disks ("initrd"), and will transition
1214 from the initrd's system manager process (a.k.a "init"
1215 process) to the main system manager process. Takes two
1216 arguments: the directory to make the new root directory, and
1217 the path to the new system manager binary below it to
1218 execute as PID 1. If the latter is omitted or the empty
1219 string, a systemd binary will automatically be searched for
1220 and used as init. If the system manager path is omitted or
1221 equal to the empty string the state of the initrd's system
1222 manager process is passed to the main system manager, which
1223 allows later introspection of the state of the services
1224 involved in the initrd boot.</para>
1232 <title>Exit status</title>
1234 <para>On success 0 is returned, a non-zero failure
1235 code otherwise.</para>
1239 <title>Environment</title>
1241 <variablelist class='environment-variables'>
1243 <term><varname>$SYSTEMD_PAGER</varname></term>
1246 <para>Pager to use when <option>--no-pager</option> is not
1247 given; overrides <varname>$PAGER</varname>. Setting this to
1248 an empty string or the value <literal>cat</literal> is
1249 equivalent to passing
1250 <option>--no-pager</option>.</para>
1257 <title>See Also</title>
1259 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1260 <citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1261 <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1262 <citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1263 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
1264 <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
1265 <citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
1266 <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>