<?xml version='1.0'?> <!--*-nxml-*-->

<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"

"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<refentry id="systemctl">

<refentryinfo>

<title>systemctl</title>

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>Developer</contrib>

<firstname>Lennart</firstname>

<surname>Poettering</surname>

<email>lennart@poettering.net</email>

</author>

</authorgroup>

</refentryinfo>

<refmeta>

<refentrytitle>systemctl</refentrytitle>

<manvolnum>1</manvolnum>

</refmeta>

<refnamediv>

<refname>systemctl</refname>

<refpurpose>Control the systemd system and service manager</refpurpose>

</refnamediv>

<refsynopsisdiv>

<cmdsynopsis>

<command>systemctl</command>

<arg choice="opt" rep="repeat">OPTIONS</arg>

<arg choice="plain">COMMAND</arg>

<arg choice="opt" rep="repeat">NAME</arg>

</cmdsynopsis>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para><command>systemctl</command> may be used to

introspect and control the state of the

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>

system and service manager.</para>

<para>For unit commands, the <replaceable>NAME</replaceable> represents full name of the unit.

<programlisting>

systemctl start foo.service

</programlisting>

For unit file commands, the <replaceable>NAME</replaceable> represents the full name of the unit file, or the absolute path to the unit file.

<programlisting>

systemctl start /path/to/foo.service

</programlisting>

While working with services/service files, <command>systemctl</command> implicitly appends the ".service" suffix when it is missing.

<programlisting>

systemctl start foo

</programlisting></para>

</refsect1>

<refsect1>

<title>Options</title>

<para>The following options are understood:</para>

<variablelist>

<varlistentry>

<term><option>-h</option></term>

<term><option>--help</option></term>

<listitem><para>Prints a short help

text and exits.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--version</option></term>

<listitem>

<para>Prints a short version string and exits.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-t</option></term>

<term><option>--type=</option></term>

<listitem>

<para>The argument should be a comma-separated list of unit

types such as <option>service</option> and

<option>socket</option>.

</para>

<para>If one of the arguments is a unit type, when listing

units, limit display to certain unit types. Otherwise, units

of all types will be shown.</para>

<para>As a special case, if one of the arguments is

<option>help</option>, a list of allowed values will be

printed and the program will exit.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--state=</option></term>

<listitem>

<para>The argument should be a comma-separated list of unit LOAD,

SUB, or ACTIVE states. When listing units, show only those

in specified states.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-p</option></term>

<term><option>--property=</option></term>

<listitem>

<para>When showing unit/job/manager properties with the

<command>show</command> command, limit display to certain

properties as specified as argument. If not specified, all

set properties are shown. The argument should be a

comma-separated list of property names, such as

<literal>MainPID</literal>. If specified more than once, all

properties with the specified names are shown.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-a</option></term>

<term><option>--all</option></term>

<listitem>

<para>When listing units, show all loaded units, regardless

of their state, including inactive units. When showing

unit/job/manager properties, show all properties regardless

whether they are set or not.</para>

<para>To list all units installed on the system, use the

<command>list-unit-files</command> command instead.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--reverse</option></term>

<listitem>

<para>Show reverse dependencies between units with

<command>list-dependencies</command>, i.e. units with

dependencies of type <varname>Wants=</varname> or

<varname>Requires=</varname> on the given unit.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--after</option></term>

<term><option>--before</option></term>

<listitem>

<para>Show which units are started after or before

with <command>list-dependencies</command>, respectively.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-l</option></term>

<term><option>--full</option></term>

<listitem>

<para>Do not ellipsize unit names, process tree entries, and

truncate unit descriptions in the output of

<command>list-units</command> and

<command>list-jobs</command>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--fail</option></term>

<listitem>

<para>If the requested operation conflicts with a pending

unfinished job, fail the command. If this is not specified,

the requested operation will replace the pending job, if

necessary. Do not confuse with

<option>--failed</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--show-types</option></term>

<listitem>

<para>When showing sockets, show the type of the socket.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--irreversible</option></term>

<listitem>

<para>Mark this transaction's jobs as irreversible. This prevents

future conflicting transactions from replacing these jobs.

The jobs can still be cancelled using the <command>cancel</command>

command.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--ignore-dependencies</option></term>

<listitem>

<para>When enqueuing a new job, ignore all its dependencies

and execute it immediately. If passed, no required units of

the unit passed will be pulled in, and no ordering

dependencies will be honored. This is mostly a debugging and

rescue tool for the administrator and should not be used by

applications.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-i</option></term>

<term><option>--ignore-inhibitors</option></term>

<listitem>

<para>When system shutdown or a sleep state is requested,

ignore inhibitor locks. Applications can establish inhibitor

locks to avoid that certain important operations (such as CD

burning or suchlike) are interrupted by system shutdown or a

sleep state. Any user may take these locks and privileged

users may override these locks. If any locks are taken,

shutdown and sleep state requests will normally fail

(regardless if privileged or not) and a list of active locks

is printed. However, if <option>--ignore-inhibitors</option>

is specified, the locks are ignored and not printed, and the

operation attempted anyway, possibly requiring additional

privileges.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-q</option></term>

<term><option>--quiet</option></term>

<listitem>

<para>Suppress output to standard output in

<command>snapshot</command>,

<command>is-active</command>,

<command>is-failed</command>,

<command>enable</command> and

<command>disable</command>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--no-block</option></term>

<listitem>

<para>Do not synchronously wait for the requested operation

to finish. If this is not specified, the job will be

verified, enqueued and <command>systemctl</command> will

wait until it is completed. By passing this argument, it is

only verified and enqueued.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--no-legend</option></term>

<listitem>

<para>Do not print a legend, i.e. the column headers and

the footer with hints.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--no-pager</option></term>

<listitem>

<para>Do not pipe output into a pager.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--system</option></term>

<listitem>

<para>Talk to the systemd system manager. (Default)</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--user</option></term>

<listitem>

<para>Talk to the systemd manager of the calling

user.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--no-wall</option></term>

<listitem>

<para>Do not send wall message before halt, power-off,

reboot.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--global</option></term>

<listitem>

<para>When used with <command>enable</command> and

<command>disable</command>, operate on the global user

configuration directory, thus enabling or disabling a unit

file globally for all future logins of all users.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--no-reload</option></term>

<listitem>

<para>When used with <command>enable</command> and

<command>disable</command>, do not implicitly reload daemon

configuration after executing the changes.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--no-ask-password</option></term>

<listitem>

<para>When used with <command>start</command> and related

commands, disables asking for passwords. Background services

may require input of a password or passphrase string, for

example to unlock system hard disks or cryptographic

certificates. Unless this option is specified and the

command is invoked from a terminal,

<command>systemctl</command> will query the user on the

terminal for the necessary secrets. Use this option to

switch this behavior off. In this case, the password must be

supplied by some other means (for example graphical password

agents) or the service might fail. This also disables

querying the user for authentication for privileged

operations.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--kill-who=</option></term>

<listitem>

<para>When used with <command>kill</command>, choose which

processes to kill. Must be one of <option>main</option>,

<option>control</option> or <option>all</option> to select

whether to kill only the main process of the unit, the

control process or all processes of the unit. If omitted,

defaults to <option>all</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-s</option></term>

<term><option>--signal=</option></term>

<listitem>

<para>When used with <command>kill</command>, choose which

signal to send to selected processes. Must be one of the

well known signal specifiers such as <constant>SIGTERM</constant>, <constant>SIGINT</constant> or

<constant>SIGSTOP</constant>. If omitted, defaults to

<option>SIGTERM</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-f</option></term>

<term><option>--force</option></term>

<listitem>

<para>When used with <command>enable</command>, overwrite

any existing conflicting symlinks.</para>

<para>When used with <command>halt</command>,

<command>poweroff</command>, <command>reboot</command> or

<command>kexec</command>, execute the selected operation

without shutting down all units. However, all processes will

be killed forcibly and all file systems are unmounted or

remounted read-only. This is hence a drastic but relatively

safe option to request an immediate reboot. If

<option>--force</option> is specified twice for these

operations, they will be executed immediately without

terminating any processes or umounting any file

systems. Warning: specifying <option>--force</option> twice

with any of these operations might result in data

loss.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--root=</option></term>

<listitem>

<para>When used with

<command>enable</command>/<command>disable</command>/<command>is-enabled</command>

(and related commands), use alternative root path when

looking for unit files.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--runtime</option></term>

<listitem>

<para>When used with <command>enable</command>,

<command>disable</command>, <command>is-enabled</command>

(and related commands), make changes only temporarily, so

that they are lost on the next reboot. This will have the

effect that changes are not made in subdirectories of

<filename>/etc</filename> but in <filename>/run</filename>,

with identical immediate effects, however, since the latter

is lost on reboot, the changes are lost too.</para>

<para>Similar, when used with

<command>set-property</command>, make changes only

temporarily, so that they are lost on the next

reboot.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-H</option></term>

<term><option>--host</option></term>

<listitem>

<para>Execute the operation remotely. Specify a hostname, or

username and hostname separated by <literal>@</literal>, to

connect to. This will use SSH to talk to the remote systemd

instance.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-M</option></term>

<term><option>--machine=</option></term>

<listitem><para>Execute the operation on a local

container. Specify a container name to connect

to.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-n</option></term>

<term><option>--lines=</option></term>

<listitem>

<para>When used with <command>status</command>, controls the

number of journal lines to show, counting from the most

recent ones. Takes a positive integer argument. Defaults to

10.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-o</option></term>

<term><option>--output=</option></term>

<listitem>

<para>When used with <command>status</command>, controls the

formatting of the journal entries that are shown. For the

available choices, see

<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.

Defaults to <literal>short</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--plain</option></term>

<listitem>

<para>When used with <command>list-dependencies</command>,

the output is printed as a list instead of a tree.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>Commands</title>

<para>The following commands are understood:</para>

<refsect2>

<title>Unit Commands</title>

<variablelist>

<varlistentry>

<term><command>list-units</command></term>

<listitem>

<para>List known units (subject to limitations specified

with <option>-t</option>).</para>

<para>This is the default command.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>list-sockets</command></term>

<listitem>

<para>List socket units ordered by the listening address. Produces output

similar to

<programlisting>

LISTEN UNIT ACTIVATES

/dev/initctl systemd-initctl.socket systemd-initctl.service

...

[::]:22 sshd.socket sshd.service

kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service

5 sockets listed.

</programlisting>

Note: because the addresses might contains spaces, this output

is not suitable for programmatic consumption.

</para>

<para>See also the options <option>--show-types</option>,

<option>--all</option>, and <option>--failed</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>list-timers</command></term>

<listitem>

<para>List timer units ordered by the time they elapse next.</para>

<para>See also the options <option>--all</option> and

<option>--failed</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>start <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Start (activate) one or more units specified on the

command line.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>stop <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Stop (deactivate) one or more units specified on the

command line.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>reload <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Asks all units listed on the command line to reload

their configuration. Note that this will reload the

service-specific configuration, not the unit configuration

file of systemd. If you want systemd to reload the

configuration file of a unit, use the

<command>daemon-reload</command> command. In other words:

for the example case of Apache, this will reload Apache's

<filename>httpd.conf</filename> in the web server, not the

<filename>apache.service</filename> systemd unit

file.</para>

<para>This command should not be confused with the

<command>daemon-reload</command> or <command>load</command>

commands.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>restart <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Restart one or more units specified on the command

line. If the units are not running yet, they will be

started.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>try-restart <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Restart one or more units specified on the command

line if the units are running. This does nothing if units are not

running. Note that, for compatibility with Red Hat init

scripts, <command>condrestart</command> is equivalent to this

command.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>reload-or-restart <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Reload one or more units if they support it. If not,

restart them instead. If the units are not running yet, they

will be started.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>reload-or-try-restart <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Reload one or more units if they support it. If not,

restart them instead. This does nothing if the units are not

running. Note that, for compatibility with SysV init scripts,

<command>force-reload</command> is equivalent to this

command.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>isolate <replaceable>NAME</replaceable></command></term>

<listitem>

<para>Start the unit specified on the command line and its

dependencies and stop all others.</para>

<para>This is similar to changing the runlevel in a

traditional init system. The <command>isolate</command>

command will immediately stop processes that are not enabled

in the new unit, possibly including the graphical

environment or terminal you are currently using.</para>

<para>Note that this is allowed only on units where

<option>AllowIsolate=</option> is enabled. See

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for details.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>kill <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Send a signal to one or more processes of the

unit. Use <option>--kill-who=</option> to select which

process to kill. Use <option>--kill-mode=</option> to select

the kill mode and <option>--signal=</option> to select the

signal to send.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>is-active <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Check whether any of the specified units are active

(i.e. running). Returns an exit code 0 if at least one is

active, non-zero otherwise. Unless <option>--quiet</option>

is specified, this will also print the current unit state to

STDOUT.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>is-failed <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Check whether any of the specified units are in a "failed" state.

Returns an exit code 0 if at least one has failed, non-zero

otherwise. Unless <option>--quiet</option> is specified, this

will also print the current unit state to

STDOUT.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>status [<replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...]</command></term>

<listitem>

<para>Show terse runtime status information about one or

more units, followed by most recent log data from the

journal. If no units are specified, show all units (subject

to limitations specified with <option>-t</option>). If a PID

is passed, show information about the unit the process

belongs to.</para>

<para>This function is intended to generate human-readable

output. If you are looking for computer-parsable output, use

<command>show</command> instead.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>show [<replaceable>NAME</replaceable>...|<replaceable>JOB</replaceable>...]</command></term>

<listitem>

<para>Show properties of one or more units, jobs, or the

manager itself. If no argument is specified, properties of

the manager will be shown. If a unit name is specified,

properties of the unit is shown, and if a job id is

specified, properties of the job is shown. By default, empty

properties are suppressed. Use <option>--all</option> to

show those too. To select specific properties to show, use

<option>--property=</option>. This command is intended to be

used whenever computer-parsable output is required. Use

<command>status</command> if you are looking for formatted

human-readable output.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>set-property <replaceable>NAME</replaceable> <replaceable>ASSIGNMENT</replaceable>...</command></term>

<listitem>

<para>Set the specified unit properties at runtime where

this is supported. This allows changing configuration

parameter properties such as resource control settings at

runtime. Not all properties may be changed at runtime, but

many resource control settings (primarily those in

<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>)

may. The changes are applied instantly, and stored on disk

for future boots, unless <option>--runtime</option> is

passed, in which case the settings only apply until the

next reboot. The syntax of the property assignment follows

closely the syntax of assignments in unit files.</para>

<para>Example: <command>systemctl set-property foobar.service CPUShares=777</command></para>

<para>Note that this command allows changing multiple

properties at the same time, which is preferable over

setting them individually. Like unit file configuration

settings, assigning the empty list to list parameters will

reset the list.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>help <replaceable>NAME</replaceable>...|<replaceable>PID</replaceable>...</command></term>

<listitem>

<para>Show manual pages for one or more units, if

available. If a PID is given, the manual pages for the unit

the process belongs to are shown.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>reset-failed [<replaceable>NAME</replaceable>...]</command></term>

<listitem>

<para>Reset the <literal>failed</literal> state of the

specified units, or if no unit name is passed, reset the state of all

units. When a unit fails in some way (i.e. process exiting

with non-zero error code, terminating abnormally or timing

out), it will automatically enter the

<literal>failed</literal> state and its exit code and status

is recorded for introspection by the administrator until the

service is restarted or reset with this command.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>list-dependencies <replaceable>NAME</replaceable></command></term>

<listitem>

<para>Shows required and wanted units of the specified

unit. If no unit is specified,

<filename>default.target</filename> is implied. Target units

are recursively expanded. When <option>--all</option> is

passed, all other units are recursively expanded as

well.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect2>

<refsect2>

<title>Unit File Commands</title>

<variablelist>

<varlistentry>

<term><command>list-unit-files</command></term>

<listitem>

<para>List installed unit files.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>enable <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Enable one or more unit files or unit file instances,

as specified on the command line. This will create a number

of symlinks as encoded in the <literal>[Install]</literal>

sections of the unit files. After the symlinks have been

created, the systemd configuration is reloaded (in a way that

is equivalent to <command>daemon-reload</command>) to ensure

the changes are taken into account immediately. Note that

this does <emphasis>not</emphasis> have the effect of also

starting any of the units being enabled. If this

is desired, a separate <command>start</command> command must

be invoked for the unit. Also note that in case of instance

enablement, symlinks named the same as instances are created in

the install location, however they all point to the same

template unit file.</para>

<para>This command will print the actions executed. This

output may be suppressed by passing <option>--quiet</option>.

</para>

<para>Note that this operation creates only the suggested

symlinks for the units. While this command is the

recommended way to manipulate the unit configuration

directory, the administrator is free to make additional

changes manually by placing or removing symlinks in the

directory. This is particularly useful to create

configurations that deviate from the suggested default

installation. In this case, the administrator must make sure

to invoke <command>daemon-reload</command> manually as

necessary to ensure the changes are taken into account.

</para>

<para>Enabling units should not be confused with starting

(activating) units, as done by the <command>start</command>

command. Enabling and starting units is orthogonal: units

may be enabled without being started and started without

being enabled. Enabling simply hooks the unit into various

suggested places (for example, so that the unit is

automatically started on boot or when a particular kind of

hardware is plugged in). Starting actually spawns the daemon

process (in case of service units), or binds the socket (in

case of socket units), and so on.</para>

<para>Depending on whether <option>--system</option>,

<option>--user</option>, <option>--runtime</option>,

or <option>--global</option> is specified, this enables the unit

for the system, for the calling user only, for only this boot of

the system, or for all future logins of all users, or only this

boot. Note that in the last case, no systemd daemon

configuration is reloaded.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>disable <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Disables one or more units. This removes all symlinks

to the specified unit files from the unit configuration

directory, and hence undoes the changes made by

<command>enable</command>. Note however that this removes

all symlinks to the unit files (i.e. including manual

additions), not just those actually created by

<command>enable</command>. This call implicitly reloads the

systemd daemon configuration after completing the disabling

of the units. Note that this command does not implicitly

stop the units that are being disabled. If this is desired,

an additional <command>stop</command> command should be

executed afterwards.</para>

<para>This command will print the actions executed. This

output may be suppressed by passing <option>--quiet</option>.

</para>

<para>This command honors <option>--system</option>,

<option>--user</option>, <option>--runtime</option> and

<option>--global</option> in a similar way as

<command>enable</command>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>is-enabled <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Checks whether any of the specified unit files are

enabled (as with <command>enable</command>). Returns an exit

code of 0 if at least one is enabled, non-zero

otherwise. Prints the current enable status. To suppress

this output, use <option>--quiet</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>reenable <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Reenable one or more unit files, as specified on the

command line. This is a combination of

<command>disable</command> and <command>enable</command> and

is useful to reset the symlinks a unit is enabled with to

the defaults configured in the <literal>[Install]</literal>

section of the unit file.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>preset <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Reset one or more unit files, as specified on the

command line, to the defaults configured in the preset

policy files. This has the same effect as

<command>disable</command> or <command>enable</command>,

depending how the unit is listed in the preset files. For

more information on the preset policy format, see

<citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>.

For more information on the concept of presets, please

consult the

<ulink url="http://freedesktop.org/wiki/Software/systemd/Preset">Preset</ulink>

document.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>mask <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Mask one or more unit files, as specified on the

command line. This will link these units to

<filename>/dev/null</filename>, making it impossible to

start them. This is a stronger version of

<command>disable</command>, since it prohibits all kinds of

activation of the unit, including manual activation. Use

this option with care. This honors the

<option>--runtime</option> option to only mask temporarily

until the next reoobt of the system.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>unmask <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Unmask one or more unit files, as specified on the

command line. This will undo the effect of

<command>mask</command>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>link <replaceable>FILENAME</replaceable>...</command></term>

<listitem>

<para>Link a unit file that is not in the unit file search

paths into the unit file search path. This requires an

absolute path to a unit file. The effect of this can be

undone with <command>disable</command>. The effect of this

command is that a unit file is available for

<command>start</command> and other commands although it

is not installed directly in the unit search path.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>get-default</command></term>

<listitem>

<para>Get the default target specified

via <filename>default.target</filename> link.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>set-default <replaceable>NAME</replaceable></command></term>

<listitem>

<para>Set the default target to boot into. Command links

<filename>default.target</filename> to the given unit.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect2>

<refsect2>

<title>Job Commands</title>

<variablelist>

<varlistentry>

<term><command>list-jobs</command></term>

<listitem>

<para>List jobs that are in progress.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>cancel <replaceable>JOB</replaceable>...</command></term>

<listitem>

<para>Cancel one or more jobs specified on the command line

by their numeric job IDs. If no job ID is specified, cancel

all pending jobs.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect2>

<refsect2>

<title>Snapshot Commands</title>

<variablelist>

<varlistentry>

<term><command>snapshot [<replaceable>NAME</replaceable>]</command></term>

<listitem>

<para>Create a snapshot. If a snapshot name is specified,

the new snapshot will be named after it. If none is

specified, an automatic snapshot name is generated. In either

case, the snapshot name used is printed to STDOUT, unless

<option>--quiet</option> is specified.</para>

<para>A snapshot refers to a saved state of the systemd

manager. It is implemented itself as a unit that is

generated dynamically with this command and has dependencies

on all units active at the time. At a later time, the user

may return to this state by using the

<command>isolate</command> command on the snapshot unit.

</para>

<para>Snapshots are only useful for saving and restoring

which units are running or are stopped, they do not

save/restore any other state. Snapshots are dynamic and lost

on reboot.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>delete <replaceable>NAME</replaceable>...</command></term>

<listitem>

<para>Remove a snapshot previously created with

<command>snapshot</command>.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect2>

<refsect2>

<title>Environment Commands</title>

<variablelist>

<varlistentry>

<term><command>show-environment</command></term>

<listitem>

<para>Dump the systemd manager environment block. The

environment block will be dumped in straight-forward form

suitable for sourcing into a shell script. This environment

block will be passed to all processes the manager

spawns.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>set-environment <replaceable>VARIABLE=VALUE</replaceable>...</command></term>

<listitem>

<para>Set one or more systemd manager environment variables,

as specified on the command line.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>unset-environment <replaceable>VARIABLE</replaceable>...</command></term>

<listitem>

<para>Unset one or more systemd manager environment

variables. If only a variable name is specified, it will be

removed regardless of its value. If a variable and a value

are specified, the variable is only removed if it has the

specified value.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect2>

<refsect2>

<title>Manager Lifecycle Commands</title>

<variablelist>

<varlistentry>

<term><command>daemon-reload</command></term>

<listitem>

<para>Reload systemd manager configuration. This will reload

all unit files and recreate the entire dependency

tree. While the daemon is being reloaded, all sockets systemd

listens on on behalf of user configuration will stay

accessible.</para> <para>This command should not be confused

with the <command>load</command> or

<command>reload</command> commands.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>daemon-reexec</command></term>

<listitem>

<para>Reexecute the systemd manager. This will serialize the

manager state, reexecute the process and deserialize the

state again. This command is of little use except for

debugging and package upgrades. Sometimes, it might be

helpful as a heavy-weight <command>daemon-reload</command>.

While the daemon is being reexecuted, all sockets systemd listening

on behalf of user configuration will stay accessible.

</para>

</listitem>

</varlistentry>

</variablelist>

</refsect2>

<refsect2>

<title>System Commands</title>

<variablelist>

<varlistentry>

<term><command>default</command></term>

<listitem>

<para>Enter default mode. This is mostly equivalent to

<command>isolate default.target</command>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>rescue</command></term>

<listitem>

<para>Enter rescue mode. This is mostly equivalent to

<command>isolate rescue.target</command>, but also prints a

wall message to all users.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>emergency</command></term>

<listitem>

<para>Enter emergency mode. This is mostly equivalent to

<command>isolate emergency.target</command>, but also prints

a wall message to all users.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>halt</command></term>

<listitem>

<para>Shut down and halt the system. This is mostly equivalent to

<command>start halt.target --irreversible</command>, but also

prints a wall message to all users. If combined with

<option>--force</option>, shutdown of all running services is

skipped, however all processes are killed and all file

systems are unmounted or mounted read-only, immediately

followed by the system halt. If <option>--force</option> is

specified twice, the operation is immediately executed

without terminating any processes or unmounting any file

systems. This may result in data loss.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>poweroff</command></term>

<listitem>

<para>Shut down and power-off the system. This is mostly

equivalent to <command>start poweroff.target --irreversible</command>,

but also prints a wall message to all users. If combined with

<option>--force</option>, shutdown of all running services is

skipped, however all processes are killed and all file

systems are unmounted or mounted read-only, immediately

followed by the powering off. If <option>--force</option> is

specified twice, the operation is immediately executed

without terminating any processes or unmounting any file

systems. This may result in data loss.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>reboot <optional><replaceable>arg</replaceable></optional></command></term>

<listitem>

<para>Shut down and reboot the system. This is mostly

equivalent to <command>start reboot.target --irreversible</command>,

but also prints a wall message to all users. If combined with

<option>--force</option>, shutdown of all running services is

skipped, however all processes are killed and all file

systems are unmounted or mounted read-only, immediately

followed by the reboot. If <option>--force</option> is

specified twice, the operation is immediately executed

without terminating any processes or unmounting any file

systems. This may result in data loss.</para>

<para>If the optional argument

<replaceable>arg</replaceable> is given, it will be passed

as the optional argument to the

<citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>

system call. The value is architecture and firmware

specific. As an example, <literal>recovery</literal> might

be used to trigger system recovery, and

<literal>fota</literal> might be used to trigger a

<quote>firmware over the air</quote> update.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>kexec</command></term>

<listitem>

<para>Shut down and reboot the system via kexec. This is

mostly equivalent to <command>start kexec.target --irreversible</command>,

but also prints a wall message to all users. If combined

with <option>--force</option>, shutdown of all running

services is skipped, however all processes are killed and

all file systems are unmounted or mounted read-only,

immediately followed by the reboot.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>exit</command></term>

<listitem>

<para>Ask the systemd manager to quit. This is only

supported for user service managers (i.e. in conjunction

with the <option>--user</option> option) and will fail

otherwise.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>suspend</command></term>

<listitem>

<para>Suspend the system. This will trigger activation of

the special <filename>suspend.target</filename> target.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>hibernate</command></term>

<listitem>

<para>Hibernate the system. This will trigger activation of

the special <filename>hibernate.target</filename> target.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>hybrid-sleep</command></term>

<listitem>

<para>Hibernate and suspend the system. This will trigger

activation of the special

<filename>hybrid-sleep.target</filename> target.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><command>switch-root <replaceable>ROOT</replaceable> [<replaceable>INIT</replaceable>]</command></term>

<listitem>

<para>Switches to a different root directory and executes a

new system manager process below it. This is intended for

usage in initial RAM disks ("initrd"), and will transition

from the initrd's system manager process (a.k.a "init"

process) to the main system manager process. This call takes two

arguments: the directory that is to become the new root directory, and

the path to the new system manager binary below it to

execute as PID 1. If the latter is omitted or the empty

string, a systemd binary will automatically be searched for

and used as init. If the system manager path is omitted or

equal to the empty string, the state of the initrd's system

manager process is passed to the main system manager, which

allows later introspection of the state of the services

involved in the initrd boot.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect2>

</refsect1>

<refsect1>

<title>Exit status</title>

<para>On success, 0 is returned, a non-zero failure

code otherwise.</para>

</refsect1>

<refsect1>

<title>Environment</title>

<variablelist class='environment-variables'>

<varlistentry>

<term><varname>$SYSTEMD_PAGER</varname></term>

<listitem>

<para>Pager to use when <option>--no-pager</option> is not

given; overrides <varname>$PAGER</varname>. Setting this to

an empty string or the value <literal>cat</literal> is

equivalent to passing

<option>--no-pager</option>.</para>

</listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>See Also</title>

<para>

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemadm</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>loginctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.resource-management</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,

<citerefentry><refentrytitle>wall</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry>

</para>

</refsect1>

</refentry>