# systemctl

## NAME



           systemctl - Control the systemd system and service manager
    


## SYNOPSIS



    
           **systemctl**[OPTIONS...] COMMAND [UNIT...]
    


## DESCRIPTION



           **systemctl** may be used to introspect and control the state of the
           "systemd" system and service manager. Please refer to systemd(1)
           for an introduction into the basic concepts and functionality this
           tool manages.
    


## COMMANDS



           The following commands are understood:
    
       **Unit Commands (Introspection and Modification)**
           **list-units**[_PATTERN_...]
               List units that **systemd** currently has in memory. This includes
               units that are either referenced directly or through a
               dependency, units that are pinned by applications
               programmatically, or units that were active in the past and
               have failed. By default, only units which are active, have
               pending jobs, or have failed are shown; this can be changed
               with option **--all**. If one or more _PATTERN_ s are specified, only
               units matching one of them are shown. The units that are shown
               are additionally filtered by **--type=** and **--state=** if those
               options are specified.
    
               Note that this command does not show unit templates, but only
               instances of unit templates. Units templates that are not
               instantiated are not runnable, and will thus never show up in
               the output of this command. Specifically this means that
               foo@.service will never be shown in this list — unless
               instantiated, e.g. as foo@bar.service. Use **list-unit-files**
               (see below) for listing installed unit template files.
    
               Produces output similar to
    
                     UNIT                         LOAD   ACTIVE SUB     DESCRIPTION
                     sys-module-fuse.device       loaded active plugged /sys/module/fuse
                     -.mount                      loaded active mounted Root Mount
                     boot-efi.mount               loaded active mounted /boot/efi
                     systemd-journald.service     loaded active running Journal Service
                     systemd-logind.service       loaded active running Login Service
                   ● user@1000.service            loaded failed failed  User Manager for UID 1000
                     ...
                     systemd-tmpfiles-clean.timer loaded active waiting Daily Cleanup of Temporary Directories
    
                   LOAD   = Reflects whether the unit definition was properly loaded.
                   ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
                   SUB    = The low-level unit activation state, values depend on unit type.
    
                   123 loaded units listed. Pass --all to see loaded but inactive units, too.
                   To show all installed unit files use 'systemctl list-unit-files'.
    
               The header and the last unit of a given type are underlined if
               the terminal supports that. A colored dot is shown next to
               services which were masked, not found, or otherwise failed.
    
               The LOAD column shows the load state, one of **loaded** ,
               **not-found** , **bad-setting** , **error** , **masked**. The ACTIVE columns
               shows the general unit state, one of the following:
    
               **Table 1. Unit ACTIVE states**
               ┌──────────────┬──────────────────────────┐
               │ **State** │ **Description** │
               ├──────────────┼──────────────────────────┤
               │ _active_       │ Started, bound, plugged  │
               │              │ in, ..., depending on    │
               │              │ the unit type.           │
               ├──────────────┼──────────────────────────┤
               │ _inactive_     │ Stopped, unbound,        │
               │              │ unplugged, ...,          │
               │              │ depending on the unit    │
               │              │ type.                    │
               ├──────────────┼──────────────────────────┤
               │ _failed_       │ Similar to **inactive** , but │
               │              │ the unit failed in some  │
               │              │ way (process returned    │
               │              │ error code on exit,      │
               │              │ crashed, an operation    │
               │              │ timed out, or after too  │
               │              │ many restarts).          │
               ├──────────────┼──────────────────────────┤
               │ _activating_   │ Changing from **inactive** │
               │              │ to **active**.               │
               ├──────────────┼──────────────────────────┤
               │ _deactivating_ │ Changing from **active** to  │
               │              │ **inactive**.                │
               ├──────────────┼──────────────────────────┤
               │ _maintenance_  │ Unit is **inactive** and a   │
               │              │ maintenance operation is │
               │              │ in progress.             │
               ├──────────────┼──────────────────────────┤
               │ _reloading_    │ Unit is **active** and it is │
               │              │ reloading its            │
               │              │ configuration.           │
               ├──────────────┼──────────────────────────┤
               │ _refreshing_   │ Unit is **active** and a new │
               │              │ mount is being activated │
               │              │ in its namespace.        │
               └──────────────┴──────────────────────────┘
    
               The SUB column shows the unit-type-specific detailed state of
               the unit, possible values vary by unit type. The list of
               possible LOAD, ACTIVE, and SUB states is not constant and new
               systemd releases may both add and remove values.
    
                   systemctl --state=help
    
               command may be used to display the current set of possible
               values.
    
               This is the default command.
    
           **list-automounts**[_PATTERN_...]
               List automount units currently in memory, ordered by mount
               path. If one or more _PATTERN_ s are specified, only automount
               units matching one of them are shown. Produces output similar
               to
    
                   WHAT        WHERE                    MOUNTED IDLE TIMEOUT UNIT
                   /dev/sdb1   /mnt/test                no      120s         mnt-test.automount
                   binfmt_misc /proc/sys/fs/binfmt_misc yes     0            proc-sys-fs-binfmt_misc.automount
    
                   2 automounts listed.
    
               Also see **--show-types** , **--all** , and **--state=**.
    
               Added in version 252.
    
           **list-paths**[_PATTERN_...]
               List path units currently in memory, ordered by path. If one
               or more _PATTERN_ s are specified, only path units matching one
               of them are shown. Produces output similar to
    
                   PATH                           CONDITION         UNIT                               ACTIVATES
                   /run/systemd/ask-password      DirectoryNotEmpty systemd-ask-password-plymouth.path systemd-ask-password-plymouth.service
                   /run/systemd/ask-password      DirectoryNotEmpty systemd-ask-password-wall.path     systemd-ask-password-wall.service
                   /var/cache/cups/org.cups.cupsd PathExists        cups.path                          cups.service
    
                   3 paths listed.
    
               Also see **--show-types** , **--all** , and **--state=**.
    
               Added in version 254.
    
           **list-sockets**[_PATTERN_...]
               List socket units currently in memory, ordered by listening
               address. If one or more _PATTERN_ s are specified, only socket
               units matching one of them are shown. Produces output similar
               to
    
                   LISTEN           UNIT                        ACTIVATES
                   kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service
                   /dev/rfkill      systemd-rfkill.socket       systemd-rfkill.service
                   ...
    
                   5 sockets listed.
    
               Note: because the addresses might contains spaces, this output
               is not suitable for programmatic consumption.
    
               Also see **--show-types** , **--all** , and **--state=**.
    
               Added in version 202.
    
           **list-timers**[_PATTERN_...]
               List timer units currently in memory, ordered by the time they
               elapse next. If one or more _PATTERN_ s are specified, only units
               matching one of them are shown. Produces output similar to
    
                   NEXT                         LEFT          LAST                         PASSED     UNIT                         ACTIVATES
                   -                            -             Thu 2017-02-23 13:40:29 EST  3 days ago ureadahead-stop.timer        ureadahead-stop.service
                   Sun 2017-02-26 18:55:42 EST  1min 14s left Thu 2017-02-23 13:54:44 EST  3 days ago systemd-tmpfiles-clean.timer systemd-tmpfiles-clean.service
                   Sun 2017-02-26 20:37:16 EST  1h 42min left Sun 2017-02-26 11:56:36 EST  6h ago     apt-daily.timer              apt-daily.service
                   Sun 2017-02-26 20:57:49 EST  2h 3min left  Sun 2017-02-26 11:56:36 EST  6h ago     snapd.refresh.timer          snapd.refresh.service
    
               _NEXT_ shows the next time the timer will run.
    
               _LEFT_ shows how long till the next time the timer runs.
    
               _LAST_ shows the last time the timer ran.
    
               _PASSED_ shows how long has passed since the timer last ran.
    
               _UNIT_ shows the name of the timer
    
               _ACTIVATES_ shows the name the service the timer activates when
               it runs.
    
               Also see **--all** and **--state=**.
    
               Added in version 209.
    
           **is-active** _PATTERN_**...**
               Check whether any of the specified units are active (i.e.
               running). Returns an exit code **0** if at least one is active, or
               non-zero otherwise. Unless **--quiet** is specified, this will
               also print the current unit state to standard output.
    
           **is-failed [**_PATTERN_...]
               Check whether any of the specified units is in the "failed"
               state. If no unit is specified, check whether there are any
               failed units, which corresponds to the "degraded" state
               returned by **is-system-running**. Returns an exit code **0** if at
               least one has failed, non-zero otherwise. Unless **--quiet** is
               specified, this will also print the current unit or system
               state to standard output.
    
               Added in version 197.
    
           **status**[_PATTERN_...|_PID_...]]
               Show runtime status information about the whole system or
               about one or more units followed by most recent log data from
               the journal. If no positional arguments are specified, and no
               unit filter is given with **--type=** , **--state=** , or **--failed** ,
               shows the status of the whole system. If combined with **--all** ,
               follows that with the status of all units. If positional
               arguments are specified, each positional argument is treated
               as either a unit name to show, or a glob pattern to show units
               whose names match that pattern, or a PID to show the unit
               containing that PID. When **--type=** , **--state=** , or **--failed** are
               used, units are additionally filtered by the TYPE and ACTIVE
               state.
    
               This function is intended to generate human-readable output.
               If you are looking for computer-parsable output, use **show**
               instead. By default, this function only shows 10 lines of
               output and ellipsizes lines to fit in the terminal window.
               This can be changed with **--lines** and **--full** , see above. In
               addition, **journalctl --unit=**_NAME_ or **journalctl**
               **--user-unit=**_NAME_ use a similar filter for messages and might
               be more convenient.
    
               Note that this operation only displays _runtime_ status, i.e.
               information about the current invocation of the unit (if it is
               running) or the most recent invocation (if it is not running
               anymore, and has not been released from memory). Information
               about earlier invocations, invocations from previous system
               boots, or prior invocations that have already been released
               from memory may be retrieved via **journalctl --unit=**.
    
               systemd implicitly loads units as necessary, so just running
               the **status** will attempt to load a file. The command is thus
               not useful for determining if something was already loaded or
               not. The units may possibly also be quickly unloaded after the
               operation is completed if there's no reason to keep it in
               memory thereafter.
    
               **Example 1. Example output from systemctl status**
    
                   $ systemctl status bluetooth
                   ● bluetooth.service - Bluetooth service
                      Loaded: loaded (/usr/lib/systemd/system/bluetooth.service; enabled; preset: enabled)
                      Active: active (running) since Wed 2017-01-04 13:54:04 EST; 1 weeks 0 days ago
                        Docs: man:bluetoothd(8)
                    Main PID: 930 (bluetoothd)
                      Status: "Running"
                       Tasks: 1
                      Memory: 648.0K
                         CPU: 435ms
                      CGroup: /system.slice/bluetooth.service
                              └─930 /usr/lib/bluetooth/bluetoothd
    
                   Jan 12 10:46:45 example.com bluetoothd[8900]: Not enough free handles to register service
                   Jan 12 10:46:45 example.com bluetoothd[8900]: Current Time Service could not be registered
                   Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output error (5)
    
               The dot ("●") uses color on supported terminals to summarize
               the unit state at a glance. Along with its color, its shape
               varies according to its state: "inactive" or "maintenance" is
               a white circle ("○"), "active" is a green dot ("●"),
               "deactivating" is a white dot, "failed" or "error" is a red
               cross ("×"), and "reloading" or "refreshing" is a green
               clockwise circle arrow ("↻").
    
               The "Loaded:" line in the output will show "loaded" if the
               unit has been loaded into memory. Other possible values for
               "Loaded:" include: "error" if there was a problem loading it,
               "not-found" if no unit file was found for this unit,
               "bad-setting" if an essential unit file setting could not be
               parsed and "masked" if the unit file has been masked. Along
               with showing the path to the unit file, this line will also
               show the enablement state. Enabled units are included in the
               dependency network between units, and thus are started at boot
               or via some other form of activation. See the full table of
               possible enablement states — including the definition of
               "masked" — in the documentation for the **is-enabled** command.
    
               The "Active:" line shows active state. The value is usually
               "active" or "inactive". Active could mean started, bound,
               plugged in, etc depending on the unit type. The unit could
               also be in process of changing states, reporting a state of
               "activating" or "deactivating". A special "failed" state is
               entered when the service failed in some way, such as a crash,
               exiting with an error code or timing out. If the failed state
               is entered the cause will be logged for later reference.
    
           **show**[_PATTERN_...|_JOB_...]
               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 are shown, and if a job ID is specified, properties of
               the job are shown. By default, empty properties are
               suppressed. Use **--all** to show those too. To select specific
               properties to show, use **--property=**. This command is intended
               to be used whenever computer-parsable output is required. Use
               **status** if you are looking for formatted human-readable output.
    
               Many properties shown by **systemctl show** map directly to
               configuration settings of the system and service manager and
               its unit files. Note that the properties shown by the command
               are generally more low-level, normalized versions of the
               original configuration settings and expose runtime state in
               addition to configuration. For example, properties shown for
               service units include the service's current main process
               identifier as "MainPID" (which is runtime state), and time
               settings are always exposed as properties ending in the
               "...USec" suffix even if a matching configuration options end
               in "...Sec", because microseconds is the normalized time unit
               used internally by the system and service manager.
    
               For details about many of these properties, see the
               documentation of the D-Bus interface backing these properties,
               see org.freedesktop.systemd1(5).
    
           **cat** _PATTERN_**...**
               Show backing files of one or more units. Prints the "fragment"
               and "drop-ins" (source files) of units. Each file is preceded
               by a comment which includes the file name. Note that this
               shows the contents of the backing files on disk, which might
               not match the system manager's understanding of these units if
               any unit files were updated on disk and the **daemon-reload**
               command was not issued since.
    
               Added in version 209.
    
           **help** _PATTERN_**...|**_PID_**...**
               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.
    
               Added in version 185.
    
           **list-dependencies**[_UNIT_...]
               Shows units required and wanted by the specified units. This
               recursively lists units following the _Requires=_ , _Requisite=_ ,
               _Wants=_ , _ConsistsOf=_ , _BindsTo=_ , and _Upholds=_ dependencies. If
               no units are specified, default.target is implied.
    
               The units that are shown are additionally filtered by **--type=**
               and **--state=** if those options are specified. Note that we will
               not be able to use a tree structure in this case, so **--plain**
               is implied.
    
               By default, only target units are recursively expanded. When
               **--all** is passed, all other units are recursively expanded as
               well.
    
               Options **--reverse** , **--after** , **--before** may be used to change
               what types of dependencies are shown.
    
               Note that this command only lists units currently loaded into
               memory by the service manager. In particular, this command is
               not suitable to get a comprehensive list at all reverse
               dependencies on a specific unit, as it will not list the
               dependencies declared by units currently not loaded.
    
               Added in version 198.
    
           **start** _PATTERN_**...**
               Start (activate) one or more units specified on the command
               line.
    
               Note that unit glob patterns expand to names of units
               currently in memory. Units which are not active and are not in
               a failed state usually are not in memory, and will not be
               matched by any pattern. In addition, in case of instantiated
               units, systemd is often unaware of the instance name until the
               instance has been started. Therefore, using glob patterns with
               **start** has limited usefulness. Also, secondary alias names of
               units are not considered.
    
               Option **--all** may be used to also operate on inactive units
               which are referenced by other loaded units. Note that this is
               not the same as operating on "all" possible units, because as
               the previous paragraph describes, such a list is ill-defined.
               Nevertheless, **systemctl start --all** _GLOB_ may be useful if all
               the units that should match the pattern are pulled in by some
               target which is known to be loaded.
    
           **stop** _PATTERN_**...**
               Stop (deactivate) one or more units specified on the command
               line.
    
               This command will fail if the unit does not exist or if
               stopping of the unit is prohibited (see _RefuseManualStop=_ in
               systemd.unit(5)). It will _not_ fail if any of the commands
               configured to stop the unit (_ExecStop=_ , etc.) fail, because
               the manager will still forcibly terminate the unit.
    
               If a unit that gets stopped can still be triggered by other
               units, a warning containing the names of the triggering units
               is shown.  **--no-warn** can be used to suppress the warning.
    
           **reload** _PATTERN_**...**
               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 **daemon-reload** command. In other words: for the example
               case of Apache, this will reload Apache's httpd.conf in the
               web server, not the apache.service systemd unit file.
    
               This command should not be confused with the **daemon-reload**
               command.
    
           **restart** _PATTERN_**...**
               Stop and then start one or more units specified on the command
               line. If the units are not running yet, they will be started.
    
               Note that restarting a unit with this command does not
               necessarily flush out all of the unit's resources before it is
               started again. For example, the per-service file descriptor
               storage facility (see _FileDescriptorStoreMax=_ in
               systemd.service(5)) will remain intact as long as the unit has
               a job pending, and is only cleared when the unit is fully
               stopped and no jobs are pending anymore. If it is intended
               that the file descriptor store is flushed out, too, during a
               restart operation an explicit **systemctl stop** command followed
               by **systemctl start** should be issued.
    
           **try-restart** _PATTERN_**...**
               Stop and then start one or more units specified on the command
               line if the units are running. This does nothing if units are
               not running.
    
           **reload-or-restart** _PATTERN_**...**
               Reload one or more units if they support it. If not, stop and
               then start them instead. If the units are not running yet,
               they will be started.
    
               This has a slightly differing functionality when used in
               combination with **--marked** , see below.
    
           **try-reload-or-restart** _PATTERN_**...**
               Reload one or more units if they support it. If not, stop and
               then start them instead. This does nothing if the units are
               not running.
    
               Added in version 229.
    
           **isolate** _UNIT_
               Start the unit specified on the command line and its
               dependencies and stop all others, unless they have
               **IgnoreOnIsolate=yes**(see systemd.unit(5)). If a unit name with
               no extension is given, an extension of ".target" will be
               assumed.
    
               This command is dangerous, since it will immediately stop
               processes that are not enabled in the new target, possibly
               including the graphical environment or terminal you are
               currently using.
    
               Note that this operation is allowed only on units where
               **AllowIsolate=** is enabled. See systemd.unit(5) for details.
    
           **kill** _PATTERN_**...**
               Send a UNIX process signal to one or more processes of the
               unit. Use **--kill-whom=** to select which process to send the
               signal to. Use **--signal=** to select the signal to send. Combine
               with **--kill-value=** to enqueue a POSIX Realtime Signal with an
               associated value.
    
           **clean** _PATTERN_**...**
               Remove the configuration, state, cache, logs, runtime or file
               descriptor store data of the specified units. Use **--what=** to
               select which kind of resource to remove. For service units
               this may be used to remove the directories configured with
               _ConfigurationDirectory=_ , _StateDirectory=_ , _CacheDirectory=_ ,
               _LogsDirectory=_ and _RuntimeDirectory=_ , see systemd.exec(5) for
               details. It may also be used to clear the file descriptor
               store as enabled via _FileDescriptorStoreMax=_ , see
               systemd.service(5) for details. For timer units this may be
               used to clear out the persistent timestamp data if _Persistent=_
               is used and **--what=state** is selected, see systemd.timer(5).
               This command only applies to units that use either of these
               settings. If **--what=** is not specified, the cache and runtime
               data as well as the file descriptor store are removed (as
               these three types of resources are generally redundant and
               reproducible on the next invocation of the unit). Multiple
               values can be separated by commas. Note that the specified
               units must be stopped to invoke this operation.
    
               **Table 2.  Possible values for --what=**
               ┌─────────────────┬──────────────────────────────┐
               │ **Value** │ **Unit Setting** │
               ├─────────────────┼──────────────────────────────┤
               │ "runtime"       │ _RuntimeDirectory=_            │
               ├─────────────────┼──────────────────────────────┤
               │ "state"         │ _StateDirectory=_              │
               ├─────────────────┼──────────────────────────────┤
               │ "cache"         │ _CacheDirectory=_              │
               ├─────────────────┼──────────────────────────────┤
               │ "logs"          │ _LogsDirectory=_               │
               ├─────────────────┼──────────────────────────────┤
               │ "configuration" │ _ConfigurationDirectory=_      │
               ├─────────────────┼──────────────────────────────┤
               │ "fdstore"       │ _FileDescriptorStorePreserve=_ │
               ├─────────────────┼──────────────────────────────┤
               │ "all"           │ All of the above             │
               ├─────────────────┼──────────────────────────────┤
               │ "help"          │ Show the supported values    │
               │                 │ and exit                     │
               └─────────────────┴──────────────────────────────┘
    
               Added in version 243.
    
           **freeze** _PATTERN_**...**
               Freeze one or more units specified on the command line using
               cgroup freezer
    
               Freezing the unit will cause all processes contained within
               the cgroup corresponding to the unit to be suspended. Being
               suspended means that unit's processes will not be scheduled to
               run on CPU until thawed. Note that this command is supported
               only on systems that use unified cgroup hierarchy. Unit is
               automatically thawed just before we execute a job against the
               unit, e.g. before the unit is stopped.
    
               Added in version 246.
    
           **thaw** _PATTERN_**...**
               Thaw (unfreeze) one or more units specified on the command
               line.
    
               This is the inverse operation to the **freeze** command and
               resumes the execution of processes in the unit's cgroup.
    
               Added in version 246.
    
           **set-property** _UNIT PROPERTY_**=**_VALUE_**...**
               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
               systemd.resource-control(5)) may. The changes are applied
               immediately, and stored on disk for future boots, unless
               **--runtime** 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.
    
               Example: **systemctl set-property foobar.service CPUWeight=200**
    
               If the specified unit appears to be inactive, the changes will
               be only stored on disk as described previously hence they will
               be effective when the unit will be started.
    
               Note that this command allows changing multiple properties at
               the same time, which is preferable over setting them
               individually.
    
               Example: **systemctl set-property foobar.service CPUWeight=200**
               **MemoryMax=2G IPAccounting=yes**
    
               Like with unit file configuration settings, assigning an empty
               setting usually resets a property to its defaults.
    
               Example: **systemctl set-property avahi-daemon.service**
               **IPAddressDeny=**
    
               Added in version 206.
    
           **bind** _UNIT PATH_ [_PATH_]
               Bind-mounts a file or directory from the host into the
               specified unit's mount namespace. The first path argument is
               the source file or directory on the host, the second path
               argument is the destination file or directory in the unit's
               mount namespace. When the latter is omitted, the destination
               path in the unit's mount namespace is the same as the source
               path on the host. When combined with the **--read-only** switch, a
               read-only bind mount is created. When combined with the
               **--mkdir** switch, the destination path is first created before
               the mount is applied.
    
               Note that this option is currently only supported for units
               that run within a mount namespace (e.g.: with **RootImage=** ,
               **PrivateMounts=** , etc.). This command supports bind-mounting
               directories, regular files, device nodes, **AF_UNIX** socket
               nodes, as well as FIFOs. The bind mount is ephemeral, and it
               is undone as soon as the current unit process exists. Note
               that the namespace mentioned here, where the bind mount will
               be added to, is the one where the main service process runs.
               Other processes (those exececuted by **ExecReload=** ,
               **ExecStartPre=** , etc.) run in distinct namespaces.
    
               If supported by the kernel, any prior mount on the selected
               target will be replaced by the new mount. If not supported,
               any prior mount will be over-mounted, but remain pinned and
               inaccessible.
    
               Added in version 248.
    
           **mount-image** _UNIT IMAGE_ [_PATH_ [_PARTITION_NAME_ :_MOUNT_OPTIONS_]]
               Mounts an image from the host into the specified unit's mount
               namespace. The first path argument is the source image on the
               host, the second path argument is the destination directory in
               the unit's mount namespace (i.e. inside
               **RootImage=** /**RootDirectory=**). The following argument, if any, is
               interpreted as a colon-separated tuple of partition name and
               comma-separated list of mount options for that partition. The
               format is the same as the service **MountImages=** setting. When
               combined with the **--read-only** switch, a ready-only mount is
               created. When combined with the **--mkdir** switch, the
               destination path is first created before the mount is applied.
    
               Note that this option is currently only supported for units
               that run within a mount namespace (i.e. with **RootImage=** ,
               **PrivateMounts=** , etc.). Note that the namespace mentioned here
               where the image mount will be added to, is the one where the
               main service process runs. Note that the namespace mentioned
               here, where the bind mount will be added to, is the one where
               the main service process runs. Other processes (those
               exececuted by **ExecReload=** , **ExecStartPre=** , etc.) run in
               distinct namespaces.
    
               If supported by the kernel, any prior mount on the selected
               target will be replaced by the new mount. If not supported,
               any prior mount will be over-mounted, but remain pinned and
               inaccessible.
    
               Example:
    
                   systemctl mount-image foo.service /tmp/img.raw /var/lib/image root:ro,nosuid
    
                   systemctl mount-image --mkdir bar.service /tmp/img.raw /var/lib/baz/img
    
               Added in version 248.
    
           **service-log-level** _SERVICE_ [_LEVEL_]
               If the _LEVEL_ argument is not given, print the current log
               level as reported by service _SERVICE_.
    
               If the optional argument _LEVEL_ is provided, then change the
               current log level of the service to _LEVEL_. The log level
               should be a typical syslog log level, i.e. a value in the
               range 0...7 or one of the strings **emerg** , **alert** , **crit** , **err** ,
               **warning** , **notice** , **info** , **debug** ; see syslog(3) for details.
    
               The service must have the appropriate _BusName=destination_
               property and also implement the generic
               org.freedesktop.LogControl1(5) interface. (systemctl will use
               the generic D-Bus protocol to access the
               org.freedesktop.LogControl1.LogLevel interface for the D-Bus
               name _destination_.)
    
               Added in version 247.
    
           **service-log-target** _SERVICE_ [_TARGET_]
               If the _TARGET_ argument is not given, print the current log
               target as reported by service _SERVICE_.
    
               If the optional argument _TARGET_ is provided, then change the
               current log target of the service to _TARGET_. The log target
               should be one of the strings **console**(for log output to the
               service's standard error stream), **kmsg**(for log output to the
               kernel log buffer), **journal**(for log output to
               systemd-journald.service(8) using the native journal
               protocol), **syslog**(for log output to the classic syslog socket
               /dev/log), **null**(for no log output whatsoever) or **auto**(for an
               automatically determined choice, typically equivalent to
               **console** if the service is invoked interactively, and **journal**
               or **syslog** otherwise).
    
               For most services, only a small subset of log targets make
               sense. In particular, most "normal" services should only
               implement **console** , **journal** , and **null**. Anything else is only
               appropriate for low-level services that are active in very
               early boot before proper logging is established.
    
               The service must have the appropriate _BusName=destination_
               property and also implement the generic
               org.freedesktop.LogControl1(5) interface. (systemctl will use
               the generic D-Bus protocol to access the
               org.freedesktop.LogControl1.LogLevel interface for the D-Bus
               name _destination_.)
    
               Added in version 247.
    
           **reset-failed [**_PATTERN_**...]**
               Reset the "failed" 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 "failed" state and its exit code and
               status is recorded for introspection by the administrator
               until the service is stopped/re-started or reset with this
               command.
    
               In addition to resetting the "failed" state of a unit it also
               resets various other per-unit properties: the start rate limit
               counter of all unit types is reset to zero, as is the restart
               counter of service units. Thus, if a unit's start limit (as
               configured with _StartLimitIntervalSec=_ /_StartLimitBurst=_) is
               hit and the unit refuses to be started again, use this command
               to make it startable again.
    
           **whoami [**_PID_**...]**
               Returns the units the processes referenced by the given PIDs
               belong to (one per line). If no PID is specified returns the
               unit the **systemctl** command is invoked in.
    
               Added in version 254.
    
       **Unit File Commands**
           **list-unit-files**[_PATTERN..._]
               List unit files installed on the system, in combination with
               their enablement state (as reported by **is-enabled**). If one or
               more _PATTERN_ s are specified, only unit files whose name
               matches one of them are shown (patterns matching unit file
               system paths are not supported).
    
               Unlike **list-units** this command will list template units in
               addition to explicitly instantiated units.
    
               Added in version 233.
    
           **enable** _UNIT_**...** , **enable** _PATH_**...**
               Enable one or more units or unit instances. This will create a
               set of symlinks, as encoded in the [Install] sections of the
               indicated unit files. After the symlinks have been created,
               the system manager configuration is reloaded (in a way
               equivalent to **daemon-reload**), in order to ensure the changes
               are taken into account immediately. Note that this does _not_
               have the effect of also starting any of the units being
               enabled. If this is desired, combine this command with the
               **--now** switch, or invoke **start** with appropriate arguments
               later. Note that in case of unit instance enablement (i.e.
               enablement of units of the form foo@bar.service), symlinks
               named the same as instances are created in the unit
               configuration directory, however they point to the single
               template unit file they are instantiated from.
    
               This command expects either valid unit names (in which case
               various unit file directories are automatically searched for
               unit files with appropriate names), or absolute paths to unit
               files (in which case these files are read directly). If a
               specified unit file is located outside of the usual unit file
               directories, an additional symlink is created, linking it into
               the unit configuration path, thus ensuring it is found when
               requested by commands such as **start**. The file system where the
               linked unit files are located must be accessible when systemd
               is started (e.g. anything underneath /home/ or /var/ is not
               allowed, unless those directories are located on the root file
               system).
    
               This command will print the file system operations executed.
               This output may be suppressed by passing **--quiet**.
    
               Note that this operation creates only the symlinks suggested
               in the [Install] section of the unit files. 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 below this
               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 **daemon-reload** manually as necessary, in order to
               ensure the changes are taken into account.
    
               When using this operation on units without install
               information, a warning about it is shown.  **--no-warn** can be
               used to suppress the warning.
    
               Enabling units should not be confused with starting
               (activating) units, as done by the **start** 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.
    
               Depending on whether **--system** , **--user** , **--runtime** , or **--global**
               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. Note that in the last case, no
               systemd daemon configuration is reloaded.
    
               Using **enable** on masked units is not supported and results in
               an error.
    
           **disable** _UNIT_**...**
               Disables one or more units. This removes all symlinks to the
               unit files backing the specified units from the unit
               configuration directory, and hence undoes any changes made by
               **enable** or **link**. Note that this removes _all_ symlinks to
               matching unit files, including manually created symlinks, and
               not just those actually created by **enable** or **link**. Note that
               while **disable** undoes the effect of **enable** , the two commands
               are otherwise not symmetric, as **disable** may remove more
               symlinks than a prior **enable** invocation of the same unit
               created.
    
               This command expects valid unit names only, it does not accept
               paths to unit files.
    
               In addition to the units specified as arguments, all units are
               disabled that are listed in the _Also=_ setting contained in the
               [Install] section of any of the unit files being operated on.
    
               This command implicitly reloads the system manager
               configuration after completing the operation. Note that this
               command does not implicitly stop the units that are being
               disabled. If this is desired, either combine this command with
               the **--now** switch, or invoke the **stop** command with appropriate
               arguments later.
    
               This command will print information about the file system
               operations (symlink removals) executed. This output may be
               suppressed by passing **--quiet**.
    
               If a unit gets disabled but its triggering units are still
               active, a warning containing the names of the triggering units
               is shown.  **--no-warn** can be used to suppress the warning.
    
               When this command is used with **--user** , the units being
               operated on might still be enabled in global scope, and thus
               get started automatically even after a successful disablement
               in user scope. In this case, a warning about it is shown,
               which can be suppressed using **--no-warn**.
    
               This command honors **--system** , **--user** , **--runtime** , **--global** and
               **--no-warn** in a similar way as **enable**.
    
               Added in version 238.
    
           **reenable** _UNIT_**...**
               Reenable one or more units, as specified on the command line.
               This is a combination of **disable** and **enable** and is useful to
               reset the symlinks a unit file is enabled with to the defaults
               configured in its [Install] section. This command expects a
               unit name only, it does not accept paths to unit files.
    
               This command implicitly reloads the system manager
               configuration after completing the operation. Note that this
               command does not implicitly restart the units that are being
               disabled. If this is desired, either combine this command with
               the **--now** switch, or invoke the **try-restart** command with
               appropriate arguments later.
    
               Added in version 238.
    
           **preset** _UNIT_**...**
               Reset the enable/disable status of 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 **disable**
               or **enable** , depending how the unit is listed in the preset
               files.
    
               Use **--preset-mode=** to control whether units shall be enabled
               and disabled, or only enabled, or only disabled.
    
               If the unit carries no install information, it will be
               silently ignored by this command.  _UNIT_ must be the real unit
               name, any alias names are ignored silently.
    
               For more information on the preset policy format, see
               systemd.preset(5).
    
               Added in version 238.
    
           **preset-all**
               Resets all installed unit files to the defaults configured in
               the preset policy file (see above).
    
               Use **--preset-mode=** to control whether units shall be enabled
               and disabled, or only enabled, or only disabled.
    
               Added in version 215.
    
           **is-enabled** _UNIT_**...**
               Checks whether any of the specified unit files are enabled (as
               with **enable**). Returns an exit code of 0 if at least one is
               enabled, non-zero otherwise. Prints the current enable status
               (see table). To suppress this output, use **--quiet**. To show
               installation targets, use **--full**.
    
               **Table 3.  is-enabled output**
               ┌───────────────────┬─────────────────────────┬───────────┐
               │ **Name** │ **Description** │ **Exit Code** │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "enabled"         │ Enabled via             │           │
               ├───────────────────┤ .wants/,                │           │
               │ "enabled-runtime" │ .requires/ or           │           │
               │                   │ _Alias=_ symlinks         │ 0         │
               │                   │ (permanently in         │           │
               │                   │ /etc/systemd/system/,   │           │
               │                   │ or transiently in       │           │
               │                   │ /run/systemd/system/).  │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "linked"          │ Made available through  │           │
               ├───────────────────┤ one or more symlinks    │           │
               │ "linked-runtime"  │ to the unit file        │           │
               │                   │ (permanently in         │           │
               │                   │ /etc/systemd/system/    │           │
               │                   │ or transiently in       │ > 0       │
               │                   │ /run/systemd/system/),  │           │
               │                   │ even though the unit    │           │
               │                   │ file might reside       │           │
               │                   │ outside of the unit     │           │
               │                   │ file search path.       │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "alias"           │ The name is an alias    │ 0         │
               │                   │ (symlink to another     │           │
               │                   │ unit file).             │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "masked"          │ Completely disabled,    │           │
               ├───────────────────┤ so that any start       │           │
               │ "masked-runtime"  │ operation on it fails   │           │
               │                   │ (permanently in         │ > 0       │
               │                   │ /etc/systemd/system/    │           │
               │                   │ or transiently in       │           │
               │                   │ /run/systemd/systemd/). │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "static"          │ The unit file is not    │ 0         │
               │                   │ enabled, and has no     │           │
               │                   │ provisions for enabling │           │
               │                   │ in the [Install] unit   │           │
               │                   │ file section.           │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "indirect"        │ The unit file itself is │ 0         │
               │                   │ not enabled, but it has │           │
               │                   │ a non-empty _Also=_       │           │
               │                   │ setting in the          │           │
               │                   │ [Install] unit file     │           │
               │                   │ section, listing other  │           │
               │                   │ unit files that might   │           │
               │                   │ be enabled, or it has   │           │
               │                   │ an alias under a        │           │
               │                   │ different name through  │           │
               │                   │ a symlink that is not   │           │
               │                   │ specified in _Also=_. For │           │
               │                   │ template unit files, an │           │
               │                   │ instance different than │           │
               │                   │ the one specified in    │           │
               │                   │ _DefaultInstance=_ is     │           │
               │                   │ enabled.                │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "disabled"        │ The unit file is not    │ > 0       │
               │                   │ enabled, but contains   │           │
               │                   │ an [Install] section    │           │
               │                   │ with installation       │           │
               │                   │ instructions.           │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "generated"       │ The unit file was       │ 0         │
               │                   │ generated dynamically   │           │
               │                   │ via a generator tool.   │           │
               │                   │ See                     │           │
               │                   │ systemd.generator(7).   │           │
               │                   │ Generated unit files    │           │
               │                   │ may not be enabled,     │           │
               │                   │ they are enabled        │           │
               │                   │ implicitly by their     │           │
               │                   │ generator.              │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "transient"       │ The unit file has been  │ 0         │
               │                   │ created dynamically     │           │
               │                   │ with the runtime API.   │           │
               │                   │ Transient units may not │           │
               │                   │ be enabled.             │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "bad"             │ The unit file is        │ > 0       │
               │                   │ invalid or another      │           │
               │                   │ error occurred. Note    │           │
               │                   │ that **is-enabled** will    │           │
               │                   │ not actually return     │           │
               │                   │ this state, but print   │           │
               │                   │ an error message        │           │
               │                   │ instead. However, the   │           │
               │                   │ unit file listing       │           │
               │                   │ printed by              │           │
               │                   │ **list-unit-files** might   │           │
               │                   │ show it.                │           │
               ├───────────────────┼─────────────────────────┼───────────┤
               │ "not-found"       │ The unit file does not  │ 4         │
               │                   │ exist.                  │           │
               └───────────────────┴─────────────────────────┴───────────┘
    
               Added in version 238.
    
           **mask** _UNIT_**...**
               Mask one or more units, as specified on the command line. This
               will link these unit files to /dev/null, making it impossible
               to start them. This is a stronger version of **disable** , since it
               prohibits all kinds of activation of the unit, including
               enablement and manual activation. Use this option with care.
               This honors the **--runtime** option to only mask temporarily
               until the next reboot of the system. The **--now** option may be
               used to ensure that the units are also stopped. This command
               expects valid unit names only, it does not accept unit file
               paths.
    
               Note that this will create a symlink under the unit's name in
               /etc/systemd/system/ (in case **--runtime** is not specified) or
               /run/systemd/system/ (in case **--runtime** is specified). If a
               matching unit file already exists under these directories this
               operation will hence fail. This means that the operation is
               primarily useful to mask units shipped by the vendor (as those
               are shipped in /usr/lib/systemd/system/ and not the
               aforementioned two directories), but typically does not work
               for units created locally (as those are typically placed
               precisely in the two aforementioned directories). Similar
               restrictions apply for **--user** mode, in which case the
               directories are below the user's home directory however.
    
               If a unit gets masked but its triggering units are still
               active, a warning containing the names of the triggering units
               is shown.  **--no-warn** can be used to suppress the warning.
    
               Added in version 238.
    
           **unmask** _UNIT_**...**
               Unmask one or more unit files, as specified on the command
               line. This will undo the effect of **mask**. This command expects
               valid unit names only, it does not accept unit file paths.
    
               Added in version 238.
    
           **link** _PATH_**...**
               Link a unit file that is not in the unit file search path into
               the unit file search path. This command expects an absolute
               path to a unit file. The effect of this may be undone with
               **disable**. The effect of this command is that a unit file is
               made available for commands such as **start** , even though it is
               not installed directly in the unit search path. The file
               system where the linked unit files are located must be
               accessible when systemd is started (e.g. anything underneath
               /home/ or /var/ is not allowed, unless those directories are
               located on the root file system).
    
               Added in version 233.
    
           **revert** _UNIT_**...**
               Revert one or more unit files to their vendor versions. This
               command removes drop-in configuration files that modify the
               specified units, as well as any user-configured unit file that
               overrides a matching vendor supplied unit file. Specifically,
               for a unit "foo.service" the matching directories
               "foo.service.d/" with all their contained files are removed,
               both below the persistent and runtime configuration
               directories (i.e. below /etc/systemd/system and
               /run/systemd/system); if the unit file has a vendor-supplied
               version (i.e. a unit file located below /usr/) any matching
               persistent or runtime unit file that overrides it is removed,
               too. Note that if a unit file has no vendor-supplied version
               (i.e. is only defined below /etc/systemd/system or
               /run/systemd/system, but not in a unit file stored below
               /usr/), then it is not removed. Also, if a unit is masked, it
               is unmasked.
    
               Effectively, this command may be used to undo all changes made
               with **systemctl edit** , **systemctl set-property** and **systemctl mask**
               and puts the original unit file with its settings back in
               effect.
    
               Added in version 230.
    
           **add-wants** _TARGET UNIT_**...** , **add-requires** _TARGET UNIT_**...**
               Adds "Wants=" or "Requires=" dependencies, respectively, to
               the specified _TARGET_ for one or more units.
    
               This command honors **--system** , **--user** , **--runtime** and **--global**
               in a way similar to **enable**.
    
               Added in version 217.
    
           **edit** _UNIT_**...**
               Edit or replace a drop-in snippet or the main unit file, to
               extend or override the definition of the specified unit.
    
               Depending on whether **--system**(the default), **--user** , or
               **--global** is specified, this command will operate on the system
               unit files, unit files for the calling user, or the unit files
               shared between all users.
    
               The editor (see the "Environment" section below) is invoked on
               temporary files which will be written to the real location if
               the editor exits successfully. After the editing is finished,
               configuration is reloaded, equivalent to **systemctl**
               **daemon-reload --system** or **systemctl daemon-reload --user**. For
               **edit --global** , the reload is not performed and the edits will
               take effect only for subsequent logins (or after a reload is
               requested in a different way).
    
               If **--full** is specified, a replacement for the main unit file
               will be created or edited. Otherwise, a drop-in file will be
               created or edited.
    
               If **--drop-in=** is specified, the given drop-in file name will
               be used instead of the default override.conf.
    
               The unit must exist, i.e. its main unit file must be present.
               If **--force** is specified, this requirement is ignored and a new
               unit may be created (with **--full**), or a drop-in for a
               nonexistent unit may be created.
    
               If **--runtime** is specified, the changes will be made
               temporarily in /run/ and they will be lost on the next reboot.
    
               If **--stdin** is specified, the new contents will be read from
               standard input. In this mode, the old contents of the file are
               discarded.
    
               If the temporary file is empty upon exit, the modification of
               the related unit is canceled.
    
               Note that this command cannot be used to remotely edit units
               and that you cannot temporarily edit units which are in /etc/,
               since they take precedence over /run/.
    
               Added in version 218.
    
           **get-default**
               Return the default target to boot into. This returns the
               target unit name default.target is aliased (symlinked) to.
    
               Added in version 205.
    
           **set-default** _TARGET_
               Set the default target to boot into. This sets (symlinks) the
               default.target alias to the given target unit.
    
               Added in version 205.
    
       **Machine Commands**
           **list-machines**[_PATTERN_...]
               List the host and all running local containers with their
               state. If one or more _PATTERN_ s are specified, only containers
               matching one of them are shown.
    
               Added in version 212.
    
       **Job Commands**
           **list-jobs [**_PATTERN..._]
               List jobs that are in progress. If one or more _PATTERN_ s are
               specified, only jobs for units matching one of them are shown.
    
               When combined with **--after** or **--before** the list is augmented
               with information on which other job each job is waiting for,
               and which other jobs are waiting for it, see above.
    
               Added in version 233.
    
           **cancel [**_JOB_...]
               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.
    
               Added in version 233.
    
       **Environment Commands**
           **systemd** supports an environment block that is passed to processes
           the manager spawns. The names of the variables can contain ASCII
           letters, digits, and the underscore character. Variable names
           cannot be empty or start with a digit. In variable values, most
           characters are allowed, but the whole sequence must be valid
           UTF-8. (Note that control characters like newline (**NL**), tab (**TAB**),
           or the escape character (**ESC**), _are_ valid ASCII and thus valid
           UTF-8). The total length of the environment block is limited to
           **_SC_ARG_MAX** value defined by sysconf(3).
    
           **show-environment**
               Dump the systemd manager environment block. This is the
               environment block that is passed to all processes the manager
               spawns. The environment block will be dumped in
               straightforward form suitable for sourcing into most shells.
               If no special characters or whitespace is present in the
               variable values, no escaping is performed, and the assignments
               have the form "VARIABLE=value". If whitespace or characters
               which have special meaning to the shell are present,
               dollar-single-quote escaping is used, and assignments have the
               form "VARIABLE=$'value'". This syntax is known to be supported
               by bash(1), **zsh**(1), **ksh**(1), and **busybox**(1)'s **ash**(1), but not
               dash(1) or **fish**(1).
    
               Note that this shows the _effective_ block, i.e. the combination
               of environment variables configured via configuration files,
               environment generators and via IPC (i.e. via the
               **set-environment** described below). At the moment a unit process
               is forked off, this combined environment block will be further
               combined with per-unit environment variables, which are not
               visible in this command.
    
           **set-environment** _VARIABLE=VALUE_**...**
               Set one or more service manager environment variables, as
               specified on the command line. This command will fail if
               variable names and values do not conform to the rules listed
               above.
    
               Note that this operates on an environment block separate from
               the environment block configured from service manager
               configuration and environment generators. Whenever a process
               is invoked the two blocks are combined (also incorporating any
               per-service environment variables), and passed to it. The
               **show-environment** verb will show the combination of the blocks,
               see above.
    
               Added in version 233.
    
           **unset-environment** _VARIABLE_**...**
               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.
    
               Note that this operates on an environment block separate from
               the environment block configured from service manager
               configuration and environment generators. Whenever a process
               is invoked the two blocks are combined (also incorporating any
               per-service environment variables), and passed to it. The
               **show-environment** verb will show the combination of the blocks,
               see above. Note that this means this command cannot be used to
               unset environment variables defined in the service manager
               configuration files or via generators.
    
               Added in version 233.
    
           **import-environment** _VARIABLE..._
               Import all, one or more environment variables set on the
               client into the systemd manager environment block. If a list
               of environment variable names is passed, client-side values
               are then imported into the manager's environment block. If any
               names are not valid environment variable names or have invalid
               values according to the rules described above, an error is
               raised. If no arguments are passed, the entire environment
               block inherited by the **systemctl** process is imported. In this
               mode, any inherited invalid environment variables are quietly
               ignored.
    
               Importing of the full inherited environment block (calling
               this command without any arguments) is deprecated. A shell
               will set dozens of variables which only make sense locally and
               are only meant for processes which are descendants of the
               shell. Such variables in the global environment block are
               confusing to other processes.
    
               Added in version 209.
    
       **Manager State Commands**
           **daemon-reload**
               Reload the systemd manager configuration. This will rerun all
               generators (see systemd.generator(7)), reload all unit files,
               and recreate the entire dependency tree. While the daemon is
               being reloaded, all sockets systemd listens on behalf of user
               configuration will stay accessible.
    
               This command should not be confused with the **reload** command.
    
           **daemon-reexec**
               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
               **daemon-reload**. While the daemon is being reexecuted, all
               sockets systemd listening on behalf of user configuration will
               stay accessible.
    
           **log-level**[_LEVEL_]
               If no argument is given, print the current log level of the
               manager. If an optional argument _LEVEL_ is provided, then the
               command changes the current log level of the manager to _LEVEL_
               (accepts the same values as **--log-level=** described in
               systemd(1)).
    
               Added in version 244.
    
           **log-target**[_TARGET_]
               If no argument is given, print the current log target of the
               manager. If an optional argument _TARGET_ is provided, then the
               command changes the current log target of the manager to
               _TARGET_ (accepts the same values as **--log-target=** , described in
               systemd(1)).
    
               Added in version 244.
    
           **service-watchdogs**[yes|no]
               If no argument is given, print the current state of service
               runtime watchdogs of the manager. If an optional boolean
               argument is provided, then globally enables or disables the
               service runtime watchdogs (**WatchdogSec=**) and emergency actions
               (e.g.  **OnFailure=** or **StartLimitAction=**); see
               systemd.service(5). The hardware watchdog is not affected by
               this setting.
    
               Added in version 244.
    
       **System Commands**
           **is-system-running**
               Checks whether the system is operational. This returns success
               (exit code 0) when the system is fully up and running,
               specifically not in startup, shutdown or maintenance mode, and
               with no failed services. Failure is returned otherwise (exit
               code non-zero). In addition, the current state is printed in a
               short string to standard output, see the table below. Use
               **--quiet** to suppress this output.
    
               Use **--wait** to wait until the boot process is completed before
               printing the current state and returning the appropriate error
               status. If **--wait** is in use, states _initializing_ or _starting_
               will not be reported, instead the command will block until a
               later state (such as _running_ or _degraded_) is reached.
    
               **Table 4. is-system-running output**
               ┌──────────────┬────────────────────┬───────────┐
               │ **Name** │ **Description** │ **Exit Code** │
               ├──────────────┼────────────────────┼───────────┤
               │ _initializing_ │ Early bootup,      │ > 0       │
               │              │ before             │           │
               │              │ basic.target is    │           │
               │              │ reached or the     │           │
               │              │ _maintenance_ state  │           │
               │              │ entered.           │           │
               ├──────────────┼────────────────────┼───────────┤
               │ _starting_     │ Late bootup,       │ > 0       │
               │              │ before the job     │           │
               │              │ queue becomes idle │           │
               │              │ for the first      │           │
               │              │ time, or one of    │           │
               │              │ the rescue targets │           │
               │              │ are reached.       │           │
               ├──────────────┼────────────────────┼───────────┤
               │ _running_      │ The system is      │ 0         │
               │              │ fully operational. │           │
               ├──────────────┼────────────────────┼───────────┤
               │ _degraded_     │ The system is      │ > 0       │
               │              │ operational but    │           │
               │              │ one or more units  │           │
               │              │ failed.            │           │
               ├──────────────┼────────────────────┼───────────┤
               │ _maintenance_  │ The rescue or      │ > 0       │
               │              │ emergency target   │           │
               │              │ is active.         │           │
               ├──────────────┼────────────────────┼───────────┤
               │ _stopping_     │ The manager is     │ > 0       │
               │              │ shutting down.     │           │
               ├──────────────┼────────────────────┼───────────┤
               │ _offline_      │ The manager is not │ > 0       │
               │              │ running.           │           │
               │              │ Specifically, this │           │
               │              │ is the operational │           │
               │              │ state if an        │           │
               │              │ incompatible       │           │
               │              │ program is running │           │
               │              │ as system manager  │           │
               │              │ (PID 1).           │           │
               ├──────────────┼────────────────────┼───────────┤
               │ _unknown_      │ The operational    │ > 0       │
               │              │ state could not be │           │
               │              │ determined, due to │           │
               │              │ lack of resources  │           │
               │              │ or another error   │           │
               │              │ cause.             │           │
               └──────────────┴────────────────────┴───────────┘
    
               Added in version 215.
    
           **default**
               Enter default mode. This is equivalent to **systemctl isolate**
               **default.target**. This operation is blocking by default, use
               **--no-block** to request asynchronous behavior.
    
           **rescue**
               Enter rescue mode. This is equivalent to **systemctl isolate**
               **rescue.target**. This operation is blocking by default, use
               **--no-block** to request asynchronous behavior.
    
           **emergency**
               Enter emergency mode. This is equivalent to **systemctl isolate**
               **emergency.target**. This operation is blocking by default, use
               **--no-block** to request asynchronous behavior.
    
           **halt**
               Shut down and halt the system. This is mostly equivalent to
               **systemctl start halt.target --job-mode=replace-irreversibly**
               **--no-block** , but also prints a wall message to all users. This
               command is asynchronous; it will return after the halt
               operation is enqueued, without waiting for it to complete.
               Note that this operation will simply halt the OS kernel after
               shutting down, leaving the hardware powered on. Use **systemctl**
               **poweroff** for powering off the system (see below).
    
               If combined with **--force** , 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 **--force** is specified twice, the operation
               is immediately executed without terminating any processes or
               unmounting any file systems. This may result in data loss.
               Note that when **--force** is specified twice the halt operation
               is executed by **systemctl** itself, and the system manager is not
               contacted. This means the command should succeed even when the
               system manager has crashed.
    
               If combined with **--when=** , shutdown will be scheduled after the
               given timestamp. And **--when=cancel** will cancel the shutdown.
    
           **poweroff**
               Shut down and power-off the system. This is mostly equivalent
               to **systemctl start poweroff.target**
               **--job-mode=replace-irreversibly --no-block** , but also prints a
               wall message to all users. This command is asynchronous; it
               will return after the power-off operation is enqueued, without
               waiting for it to complete.
    
               This command honors **--force** and **--when=** in a similar way as
               **halt**.
    
           **reboot**
               Shut down and reboot the system.
    
               This command mostly equivalent to **systemctl start**
               **reboot.target --job-mode=replace-irreversibly --no-block** , but
               also prints a wall message to all users. This command is
               asynchronous; it will return after the reboot operation is
               enqueued, without waiting for it to complete.
    
               If the switch **--reboot-argument=** is given, it will be passed
               as the optional argument to the reboot(2) system call.
    
               Options **--boot-loader-entry=** , **--boot-loader-menu=** , and
               **--firmware-setup** can be used to select what to do _after_ the
               reboot. See the descriptions of those options for details.
    
               This command honors **--force** and **--when=** in a similar way as
               **halt**.
    
               If a new kernel has been loaded via **kexec --load** , a **kexec** will
               be performed instead of a reboot, unless
               "SYSTEMCTL_SKIP_AUTO_KEXEC=1" has been set. If a new root file
               system has been set up on "/run/nextroot/", a **soft-reboot** will
               be performed instead of a reboot, unless
               "SYSTEMCTL_SKIP_AUTO_SOFT_REBOOT=1" has been set.
    
               Added in version 246.
    
           **kexec**
               Shut down and reboot the system via **kexec**. This command will
               load a kexec kernel if one was not loaded yet or fail. A
               kernel may be loaded earlier by a separate step, this is
               particularly useful if a custom initrd or additional kernel
               command line options are desired. The **--force** can be used to
               continue without a kexec kernel, i.e. to perform a normal
               reboot. The final reboot step is equivalent to **systemctl start**
               **kexec.target --job-mode=replace-irreversibly --no-block**.
    
               To load a kernel, an enumeration is performed following the
               **Boot Loader Specification******[1], and the default boot entry is
               loaded. For this step to succeed, the system must be using
               UEFI and the boot loader entries must be configured
               appropriately.**bootctl list** may be used to list boot entries,
               see bootctl(1).
    
               This command is asynchronous; it will return after the reboot
               operation is enqueued, without waiting for it to complete.
    
               This command honors **--force** and **--when=** similarly to **halt**.
    
               If a new kernel has been loaded via **kexec --load** , a **kexec** will
               be performed when **reboot** is invoked, unless
               "SYSTEMCTL_SKIP_AUTO_KEXEC=1" has been set.
    
           **soft-reboot**
               Shut down and reboot userspace. This is equivalent to
               **systemctl start soft-reboot.target**
               **--job-mode=replace-irreversibly --no-block**. This command is
               asynchronous; it will return after the reboot operation is
               enqueued, without waiting for it to complete.
    
               This command honors **--force** and **--when=** in a similar way as
               **halt**.
    
               This operation only reboots userspace, leaving the kernel
               running. See systemd-soft-reboot.service(8) for details.
    
               If a new root file system has been set up on "/run/nextroot/",
               a **soft-reboot** will be performed when **reboot** is invoked, unless
               "SYSTEMCTL_SKIP_AUTO_SOFT_REBOOT=1" has been set.
    
               Added in version 254.
    
           **exit**[_EXIT_CODE_]
               Ask the service manager to quit. This is only supported for
               user service managers (i.e. in conjunction with the **--user**
               option) or in containers and is equivalent to **poweroff**
               otherwise. This command is asynchronous; it will return after
               the exit operation is enqueued, without waiting for it to
               complete.
    
               The service manager will exit with the specified exit code, if
               _EXIT_CODE_ is passed.
    
               Added in version 227.
    
           **switch-root**[_ROOT_ [_INIT_]]
               Switches to a different root directory and executes a new
               system manager process below it. This is intended for use in
               the initrd, and will transition from the initrd's system
               manager process (a.k.a. "init" process, PID 1) to the main
               system manager process which is loaded from the actual host
               root files system. 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 both are omitted or the former is an empty string it
               defaults to /sysroot/. If the latter is omitted or is an empty
               string, a systemd binary will automatically be searched for
               and used as service manager. If the system manager path is
               omitted, equal to the empty string or identical to the path to
               the systemd binary, 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 phase.
    
               Added in version 209.
    
           **sleep**
               Put the system to sleep, through **suspend** , **hibernate** ,
               **hybrid-sleep** , or **suspend-then-hibernate**. The sleep operation
               to use is automatically selected by systemd-logind.service(8).
               By default, **suspend-then-hibernate** is used, and falls back to
               **suspend** and then **hibernate** if not supported. Refer to
               _SleepOperation=_ setting in logind.conf(5) for more details.
               This command is asynchronous, and will return after the sleep
               operation is successfully enqueued. It will not wait for the
               sleep/resume cycle to complete.
    
               Added in version 256.
    
           **suspend**
               Suspend the system. This will trigger activation of the
               special target unit suspend.target. This command is
               asynchronous, and will return after the suspend operation is
               successfully enqueued. It will not wait for the suspend/resume
               cycle to complete.
    
               If **--force** is specified, and **systemd-logind** returned error for
               the operation, the error will be ignored and the operation
               will be tried again directly through starting the target unit.
    
           **hibernate**
               Hibernate the system. This will trigger activation of the
               special target unit hibernate.target. This command is
               asynchronous, and will return after the hibernation operation
               is successfully enqueued. It will not wait for the
               hibernate/thaw cycle to complete.
    
               This command honors **--force** in the same way as **suspend**.
    
           **hybrid-sleep**
               Hibernate and suspend the system. This will trigger activation
               of the special target unit hybrid-sleep.target. This command
               is asynchronous, and will return after the hybrid sleep
               operation is successfully enqueued. It will not wait for the
               sleep/wake-up cycle to complete.
    
               This command honors **--force** in the same way as **suspend**.
    
               Added in version 196.
    
           **suspend-then-hibernate**
               Suspend the system and hibernate it when the battery is low,
               or when the delay specified in systemd-sleep.conf elapsed.
               This will trigger activation of the special target unit
               suspend-then-hibernate.target. This command is asynchronous,
               and will return after the hybrid sleep operation is
               successfully enqueued. It will not wait for the sleep/wake-up
               or hibernate/thaw cycle to complete.
    
               This command honors **--force** in the same way as **suspend**.
    
               Added in version 240.
    
       **Parameter Syntax**
           Unit commands listed above take either a single unit name
           (designated as _UNIT_), or multiple unit specifications (designated
           as _PATTERN_...). In the first case, the unit name with or without a
           suffix must be given. If the suffix is not specified (unit name is
           "abbreviated"), systemctl will append a suitable suffix,
           ".service" by default, and a type-specific suffix in case of
           commands which operate only on specific unit types. For example,
    
               # systemctl start sshd
    
           and
    
               # systemctl start sshd.service
    
           are equivalent, as are
    
               # systemctl isolate default
    
           and
    
               # systemctl isolate default.target
    
           Note that (absolute) paths to device nodes are automatically
           converted to device unit names, and other (absolute) paths to
           mount unit names.
    
               # systemctl status /dev/sda
               # systemctl status /home
    
           are equivalent to:
    
               # systemctl status dev-sda.device
               # systemctl status home.mount
    
           In the second case, shell-style globs will be matched against the
           primary names of all units currently in memory; literal unit
           names, with or without a suffix, will be treated as in the first
           case. This means that literal unit names always refer to exactly
           one unit, but globs may match zero units and this is not
           considered an error.
    
           Glob patterns use fnmatch(3), so normal shell-style globbing rules
           are used, and "*", "?", "[]" may be used. See glob(7) for more
           details. The patterns are matched against the primary names of
           units currently in memory, and patterns which do not match
           anything are silently skipped. For example:
    
               # systemctl stop "sshd@*.service"
    
           will stop all sshd@.service instances. Note that alias names of
           units, and units that are not in memory are not considered for
           glob expansion.
    
           For unit file commands, the specified _UNIT_ should be the name of
           the unit file (possibly abbreviated, see above), or the absolute
           path to the unit file:
    
               # systemctl enable foo.service
    
           or
    
               # systemctl link /path/to/foo.service
    


## OPTIONS



           The following options are understood:
    
           **-t** , **--type=**
               The argument is a comma-separated list of unit types such as
               **service** and **socket**. When units are listed with **list-units** ,
               **list-dependencies** , **show** , or **status** , only units of the
               specified types will be shown. By default, units of all types
               are shown.
    
               As a special case, if one of the arguments is **help** , a list of
               allowed values will be printed and the program will exit.
    
           **--state=**
               The argument is a comma-separated list of unit LOAD, SUB, or
               ACTIVE states. When listing units with **list-units** ,
               **list-dependencies** , **show** or **status** , show only those in the
               specified states. Use **--state=failed** or **--failed** to show only
               failed units.
    
               As a special case, if one of the arguments is **help** , a list of
               allowed values will be printed and the program will exit.
    
               Added in version 206.
    
           **-p** , **--property=**
               When showing unit/job/manager properties with the **show**
               command, limit display to properties specified in the
               argument. The argument should be a comma-separated list of
               property names, such as "MainPID". Unless specified, all known
               properties are shown. If specified more than once, all
               properties with the specified names are shown. Shell
               completion is implemented for property names.
    
               For the manager itself, **systemctl show** will show all available
               properties, most of which are derived or closely match the
               options described in systemd-system.conf(5).
    
               Properties for units vary by unit type, so showing any unit
               (even a non-existent one) is a way to list properties
               pertaining to this type. Similarly, showing any job will list
               properties pertaining to all jobs. Properties for units are
               documented in systemd.unit(5), and the pages for individual
               unit types systemd.service(5), systemd.socket(5), etc.
    
           **-P**
               Equivalent to **--value --property=** , i.e. shows the value of the
               property without the property name or "=". Note that using **-P**
               once will also affect all properties listed with
               **-p** /**--property=**.
    
               Added in version 246.
    
           **-a** , **--all**
               When listing units with **list-units** , also show inactive units
               and units which are following other units. When showing
               unit/job/manager properties, show all properties regardless
               whether they are set or not.
    
               To list all units installed in the file system, use the
               **list-unit-files** command instead.
    
               When listing units with **list-dependencies** , recursively show
               dependencies of all dependent units (by default only
               dependencies of target units are shown).
    
               When used with **status** , show journal messages in full, even if
               they include unprintable characters or are very long. By
               default, fields with unprintable characters are abbreviated as
               "blob data". (Note that the pager may escape unprintable
               characters again.)
    
           **-r** , **--recursive**
               When listing units, also show units of local containers. Units
               of local containers will be prefixed with the container name,
               separated by a single colon character (":").
    
               Added in version 212.
    
           **--reverse**
               Show reverse dependencies between units with
               **list-dependencies** , i.e. follow dependencies of type _WantedBy=_ ,
               _RequiredBy=_ , _UpheldBy=_ , _PartOf=_ , _BoundBy=_ , instead of _Wants=_
               and similar.
    
               Added in version 203.
    
           **--after**
               With **list-dependencies** , show the units that are ordered before
               the specified unit. In other words, recursively list units
               following the _After=_ dependency.
    
               Note that any _After=_ dependency is automatically mirrored to
               create a _Before=_ dependency. Temporal dependencies may be
               specified explicitly, but are also created implicitly for
               units which are _WantedBy=_ targets (see systemd.target(5)), and
               as a result of other directives (for example
               _RequiresMountsFor=_). Both explicitly and implicitly introduced
               dependencies are shown with **list-dependencies**.
    
               When passed to the **list-jobs** command, for each printed job
               show which other jobs are waiting for it. May be combined with
               **--before** to show both the jobs waiting for each job as well as
               all jobs each job is waiting for.
    
               Added in version 203.
    
           **--before**
               With **list-dependencies** , show the units that are ordered after
               the specified unit. In other words, recursively list units
               following the _Before=_ dependency.
    
               When passed to the **list-jobs** command, for each printed job
               show which other jobs it is waiting for. May be combined with
               **--after** to show both the jobs waiting for each job as well as
               all jobs each job is waiting for.
    
               Added in version 212.
    
           **--with-dependencies**
               When used with **status** , **cat** , **list-units** , and **list-unit-files** ,
               those commands print all specified units and the dependencies
               of those units.
    
               Options **--reverse** , **--after** , **--before** may be used to change
               what types of dependencies are shown.
    
               Added in version 245.
    
           **-l** , **--full**
               Do not ellipsize unit names, process tree entries, journal
               output, or truncate unit descriptions in the output of **status** ,
               **list-units** , **list-jobs** , and **list-timers**.
    
               Also, show installation targets in the output of **is-enabled**.
    
           **--value**
               When printing properties with **show** , only print the value, and
               skip the property name and "=". Also see option **-P** above.
    
               Added in version 230.
    
           **--show-types**
               When showing sockets, show the type of the socket.
    
               Added in version 202.
    
           **--job-mode=**
               When queuing a new job, this option controls how to deal with
               already queued jobs. It takes one of "fail", "lenient",
               "replace", "replace-irreversibly", "isolate",
               "ignore-dependencies", "ignore-requirements", "flush",
               "triggering", or "restart-dependencies". Defaults to
               "replace", except when the **isolate** command is used which
               implies the "isolate" job mode.
    
               If "fail" is specified and a requested operation on weak
               dependencies conflicts with a pending job (more specifically:
               causes an already pending start job to be reversed into a stop
               job or vice versa), cause the operation to fail.
    
               If "lenient" is specified and a requested operation conflicts
               with any active/activating unit, cause the operation to fail.
    
               If "replace" (the default) is specified, any conflicting
               pending job will be replaced, as necessary.
    
               If "replace-irreversibly" is specified, operate like
               "replace", but also mark the new jobs as irreversible. This
               prevents future conflicting transactions from replacing these
               jobs (or even being enqueued while the irreversible jobs are
               still pending). Irreversible jobs can still be cancelled using
               the **cancel** command. This job mode should be used on any
               transaction which pulls in shutdown.target.
    
               "isolate" is only valid for start operations and causes all
               other units to be stopped when the specified unit is started.
               This mode is always used when the **isolate** command is used.
    
               "flush" will cause all queued jobs to be canceled when the new
               job is enqueued.
    
               If "ignore-dependencies" is specified, then all unit
               dependencies are ignored for this new job and the operation is
               executed 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.
    
               "ignore-requirements" is similar to "ignore-dependencies", but
               only causes the requirement dependencies to be ignored, the
               ordering dependencies will still be honored.
    
               "triggering" may only be used with **systemctl stop**. In this
               mode, the specified unit and any active units that trigger it
               are stopped. See the discussion of _Triggers=_ in
               systemd.unit(5) for more information about triggering units.
    
               "restart-dependencies" may only be used with **systemctl start**.
               In this mode, dependencies of the specified unit will receive
               restart propagation, as if a restart job had been enqueued for
               the unit.
    
               Added in version 209.
    
           **-T** , **--show-transaction**
               When enqueuing a unit job (for example as effect of a
               **systemctl start** invocation or similar), show brief information
               about all jobs enqueued, covering both the requested job and
               any added because of unit dependencies. Note that the output
               will only include jobs immediately part of the transaction
               requested. It is possible that service start-up program code
               run as effect of the enqueued jobs might request further jobs
               to be pulled in. This means that completion of the listed jobs
               might ultimately entail more jobs than the listed ones.
    
               Added in version 242.
    
           **--fail**
               Shorthand for **--job-mode=** fail.
    
               When used with the **kill** command, if no units were killed, the
               operation results in an error.
    
               Added in version 227.
    
           **--check-inhibitors=**
               When system shutdown or sleep state is requested, this option
               controls checking of inhibitor locks. It takes one of "auto",
               "yes", and "no". Defaults to "auto", which means logind will
               perform the check and respect active inhibitor locks, but
               **systemctl** will only do a client-side check for interactive
               invocations (i.e. from a TTY), so that a more friendly and
               informative error can be returned to users.  "no" disables the
               checks both in **systemctl** and systemd-logind(8).
    
               Applications can establish inhibitor locks to prevent certain
               important operations (such as CD burning) from being
               interrupted by system shutdown or sleep. 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 (unless explicitly overridden with "no").
    
               Option **--force** provides another way to override inhibitors.
    
               Added in version 248.
    
           **-i**
               Shortcut for **--check-inhibitors=no**.
    
               Added in version 198.
    
           **--dry-run**
               Just print what would be done. Currently supported by verbs
               **halt** , **poweroff** , **reboot** , **kexec** , **suspend** , **hibernate** ,
               **hybrid-sleep** , **suspend-then-hibernate** , **default** , **rescue** ,
               **emergency** , and **exit**.
    
               Added in version 236.
    
           **-q** , **--quiet**
               Suppress printing of the results of various commands and also
               the hints about truncated log lines. This does not suppress
               output of commands for which the printed output is the only
               result (like **show**). Errors are always printed.
    
           **-v** , **--verbose**
               Display unit log output while executing unit operations.
    
               Added in version 258.
    
           **--no-warn**
               Do not generate the warnings shown by default in the following
               cases:
    
               •   when **systemctl** is invoked without procfs mounted on
                   /proc/,
    
               •   when using **enable** or **disable** on units without install
                   information (i.e. do not have or have an empty [Install]
                   section),
    
               •   when using **disable** combined with **--user** on units that are
                   enabled in global scope,
    
               •   when a **stop** -ped, **disable** -d, or **mask** -ed unit still has
                   active triggering units,
    
               •   when a unit file is changed and requires **daemon-reload**.
    
               Added in version 253.
    
           **--no-block**
               Do not synchronously wait for the requested operation to
               finish. If this is not specified, the job will be verified,
               enqueued and **systemctl** will wait until the unit's start-up is
               completed. By passing this argument, it is only verified and
               enqueued. This option may not be combined with **--wait**.
    
           **--wait**
               When used with **start** or **restart** , synchronously wait for
               started units to terminate again. This option may not be
               combined with **--no-block**. Note that this will wait forever if
               any given unit never terminates (by itself or by getting
               stopped explicitly); particularly services which use
               "RemainAfterExit=yes".
    
               When used with **is-system-running** , wait until the boot process
               is completed before returning.
    
               When used with **kill** , wait until the signalled units terminate.
               Note that this will wait forever if any given unit never
               terminates.
    
               Added in version 232.
    
           **--user**
               Talk to the service manager of the calling user, rather than
               the service manager of the system.
    
           **--system**
               Talk to the service manager of the system. This is the implied
               default.
    
           **--failed**
               List units in failed state. This is equivalent to
               **--state=failed**.
    
               Added in version 233.
    
           **--no-wall**
               Do not send wall message before halt, power-off and reboot.
    
           **--global**
               When used with **enable** and **disable** , operate on the global user
               configuration directory, thus enabling or disabling a unit
               file globally for all future logins of all users.
    
           **--no-reload**
               When used with **enable** , **disable** , **preset** , **mask** , or **unmask** , do
               not implicitly reload daemon configuration after executing the
               changes.
    
           **--kill-whom=**
               When used with **kill** , choose which processes to send a UNIX
               process signal to. Must be one of **main** , **control** , **cgroup** or **all**
               to select whether to kill only the main process, the control
               process, all processes in the unit's control group or all
               processes of the unit. The main process of the unit is the one
               that defines the life-time of it. A control process of a unit
               is one that is invoked by the manager to induce state changes
               of it. For example, all processes started due to the
               _ExecStartPre=_ , _ExecStop=_ or _ExecReload=_ settings of service
               units are control processes. Note that there is only one
               control process per unit at a time, as only one state change
               is executed at a time. For services of type _Type=forking_ , the
               initial process started by the manager for _ExecStart=_ is a
               control process, while the process ultimately forked off by
               that one is then considered the main process of the unit (if
               it can be determined). This is different for service units of
               other types, where the process forked off by the manager for
               _ExecStart=_ is always the main process itself. A service unit
               consists of zero or one main process, zero or one control
               process plus any number of additional processes part of the
               unit's control group. Not all unit types manage processes of
               these types however. For example, for mount units, control
               processes are defined (which are the invocations of
               /usr/bin/mount and /usr/bin/umount), but no main process is
               defined. If omitted, defaults to **all** , except if
               **--kill-subgroup=** is used in which case defaults to **cgroup**.
    
               Added in version 252.
    
           **--kill-value=**_INT_
               If used with the **kill** command, enqueues a signal along with
               the specified integer value parameter to the specified
               process(es). This operation is only available for POSIX
               Realtime Signals (i.e.  **--signal=SIGRTMIN+...** or
               **--signal=SIGRTMAX-...**), and ensures the signals are generated
               via the sigqueue(3) system call, rather than **kill**(3). The
               specified value must be a 32-bit signed integer, and may be
               specified either in decimal, in hexadecimal (if prefixed with
               "0x"), octal (if prefixed with "0o") or binary (if prefixed
               with "0b")
    
               If this option is used the signal will only be enqueued on the
               control or main process of the unit, never on other processes
               belonging to the unit, i.e.  **--kill-whom=all** will only affect
               main and control processes but no other processes.
    
               Added in version 254.
    
           **--kill-subgroup=**_PATH_
               Takes a control group sub-path to send signals to, for use
               with the **kill** command. By default the chosen signal is
               delivered to all processes of the unit's cgroups (as well as
               the main/control processes (if outside) – subject to
               **--kill-whom=**). But with this option a subgroup can be
               selelected instead. This functionality is only available if
               "cgroup" or "cgroup-fail" are used with **--kill-whom=** , and in
               fact the former is the default if **--kill-subgroup=** is used.
    
               The specified path may, but doesn't have to be prefixed with a
               slash, and its absence or presence has no effect, the path is
               either way taken relative to the unit's main control group
               path.
    
               This functionality is only available on units where control
               group delegation is enabled (see _Delegate=_ in
               systemd.resource-control(5)).
    
               Added in version 258.
    
           **-s** , **--signal=**
               When used with **kill** , choose which signal to send to selected
               processes. Must be one of the well-known signal specifiers
               such as **SIGTERM** , **SIGINT** or **SIGSTOP**. If omitted, defaults to
               **SIGTERM**.
    
               The special value "help" will list the known values and the
               program will exit immediately, and the special value "list"
               will list known values along with the numerical signal numbers
               and the program will exit immediately.
    
           **--what=**
               Select what type of per-unit resources to remove when the
               **clean** command is invoked, see above. Takes one of
               **configuration** , **state** , **cache** , **logs** , **runtime** , **fdstore** to select
               the type of resource. This option may be specified more than
               once, in which case all specified resource types are removed.
               Also accepts the special value **all** as a shortcut for
               specifying all six resource types. If this option is not
               specified defaults to the combination of **cache** , **runtime** and
               **fdstore** , i.e. the three kinds of resources that are generally
               considered to be redundant and can be reconstructed on next
               invocation. Note that the explicit removal of the **fdstore**
               resource type is only useful if the
               _FileDescriptorStorePreserve=_ option is enabled, since the file
               descriptor store is otherwise cleaned automatically when the
               unit is stopped.
    
               Added in version 243.
    
           **-f** , **--force**
               When used with **enable** , overwrite any existing conflicting
               symlinks.
    
               When used with **edit** , create all of the specified units which
               do not already exist.
    
               When used with **suspend** , **hibernate** , **hybrid-sleep** , or
               **suspend-then-hibernate** , the error returned by **systemd-logind**
               will be ignored, and the operation will be performed directly
               through starting the corresponding units.
    
               When used with **halt** , **poweroff** , **reboot** , or **kexec** , 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
               **--force** is specified twice for these operations (with the
               exception of **kexec**), they will be executed immediately,
               without terminating any processes or unmounting any file
               systems.
    
                   **Warning**
                   Specifying **--force** twice with any of these operations
                   might result in data loss. Note that when **--force** is
                   specified twice the selected operation is executed by
                   **systemctl** itself, and the system manager is not contacted.
                   This means the command should succeed even when the system
                   manager has crashed.
    
           **--message=**
               When used with **halt** , **poweroff** or **reboot** , set a short message
               explaining the reason for the operation. The message will be
               logged together with the default shutdown message.
    
               Added in version 225.
    
           **--now**
               When used with **enable** , **disable** , **mask** , or **reenable** , also
               start/stop/try-restart the units after the specified unit file
               operations succeed.
    
               Added in version 220.
    
           **--root=**
               When used with **enable** /**disable** /**is-enabled**(and related
               commands), use the specified root path when looking for unit
               files. If this option is present, **systemctl** will operate on
               the file system directly, instead of communicating with the
               **systemd** daemon to carry out changes.
    
           **--image=**_image_
               Takes a path to a disk image file or block device node. If
               specified, all operations are applied to file system in the
               indicated disk image. This option is similar to **--root=** , but
               operates on file systems stored in disk images or block
               devices. The disk image should either contain just a file
               system or a set of file systems within a GPT partition table,
               following the **Discoverable Partitions Specification******[2]. For
               further information on supported disk images, seesystemd-nspawn(1)'s switch of the same name.
    
               Added in version 252.
    
           **--image-policy=**_policy_
               Takes an image policy string as argument, as per
               systemd.image-policy(7). The policy is enforced when operating
               on the disk image specified via **--image=** , see above. If not
               specified, defaults to the "*" policy, i.e. all recognized
               file systems in the image are used.
    
           **--runtime**
               When used with **enable** , **disable** , **edit** , (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 /etc/ but in /run/, with identical
               immediate effects, however, since the latter is lost on
               reboot, the changes are lost too.
    
               Similarly, when used with **set-property** , make changes only
               temporarily, so that they are lost on the next reboot.
    
           **--preset-mode=**
               Takes one of "full" (the default), "enable-only",
               "disable-only". When used with the **preset** or **preset-all**
               commands, controls whether units shall be disabled and enabled
               according to the preset rules, or only enabled, or only
               disabled.
    
               Added in version 215.
    
           **-n** , **--lines=**
               When used with **status** , controls the number of journal lines to
               show, counting from the most recent ones. Takes a positive
               integer argument, or 0 to disable journal output. Defaults to
               10.
    
           **-o** , **--output=**
               When used with **status** , controls the formatting of the journal
               entries that are shown. For the available choices, see
               journalctl(1). Defaults to "short".
    
           **--firmware-setup**
               When used with the **reboot** , **poweroff** , or **halt** command, indicate
               to the system's firmware to reboot into the firmware setup
               interface for the next boot. Note that this functionality is
               not available on all systems.
    
               Added in version 220.
    
           **--boot-loader-menu=**_timeout_
               When used with the **reboot** , **poweroff** , or **halt** command, indicate
               to the system's boot loader to show the boot loader menu on
               the following boot. Takes a time value as parameter —
               indicating the menu timeout. Pass zero in order to disable the
               menu timeout. Note that not all boot loaders support this
               functionality.
    
               Added in version 242.
    
           **--boot-loader-entry=**_ID_
               When used with the **reboot** , **poweroff** , or **halt** command, indicate
               to the system's boot loader to boot into a specific boot
               loader entry on the following boot. Takes a boot loader entry
               identifier as argument, or "help" in order to list available
               entries. Note that not all boot loaders support this
               functionality.
    
               Added in version 242.
    
           **--reboot-argument=**
               This switch is used with **reboot**. The value is architecture and
               firmware specific. As an example, "recovery" might be used to
               trigger system recovery, and "fota" might be used to trigger a
               “firmware over the air” update.
    
               Added in version 246.
    
           **--plain**
               When used with **list-dependencies** , **list-units** or **list-machines** ,
               the output is printed as a list instead of a tree, and the
               bullet circles are omitted.
    
               Added in version 203.
    
           **--timestamp=**
               Change the format of printed timestamps. The following values
               may be used:
    
               **pretty**(this is the default)
                   "Day YYYY-MM-DD HH:MM:SS TZ"
    
                   Added in version 248.
    
               **unix**
                   "@seconds-since-the-epoch"
    
                   Added in version 251.
    
               **us** , **μs**
                   "Day YYYY-MM-DD HH:MM:SS.UUUUUU TZ"
    
                   Added in version 248.
    
               **utc**
                   "Day YYYY-MM-DD HH:MM:SS UTC"
    
                   Added in version 248.
    
               **us+utc** , **μs+utc**
                   "Day YYYY-MM-DD HH:MM:SS.UUUUUU UTC"
    
                   Added in version 248.
    
               Added in version 247.
    
           **--mkdir**
               When used with **bind** , creates the destination file or directory
               before applying the bind mount. Note that even though the name
               of this option suggests that it is suitable only for
               directories, this option also creates the destination file
               node to mount over if the object to mount is not a directory,
               but a regular file, device node, socket or FIFO.
    
               Added in version 248.
    
           **--marked**
               Only allowed with **reload-or-restart**. Enqueues restart jobs for
               all units that have the "needs-restart" mark, and reload jobs
               for units that have the "needs-reload" mark. When a unit
               marked for reload does not support reload, restart will be
               queued. Those properties can be set using **set-property**
               **Markers=...**.
    
               Unless **--no-block** is used, **systemctl** will wait for the queued
               jobs to finish.
    
               Added in version 248.
    
           **--read-only**
               When used with **bind** , creates a read-only bind mount.
    
               Added in version 248.
    
           **--drop-in=**_NAME_
               When used with **edit** , use _NAME_ as the drop-in file name instead
               of override.conf.
    
               Added in version 253.
    
           **--when=**
               When used with **halt** , **poweroff** , **reboot** or **kexec** , schedule the
               action to be performed at the given timestamp, which should
               adhere to the syntax documented in systemd.time(7) section
               "PARSING TIMESTAMPS". Specially, if "show" is given, the
               currently scheduled action will be shown, which can be
               canceled by passing an empty string or "cancel".  "auto" will
               schedule the action according to maintenance window or one
               minute in the future.
    
               Added in version 254.
    
           **--stdin**
               When used with **edit** , the contents of the file will be read
               from standard input and the editor will not be launched. In
               this mode, the old contents of the file are completely
               replaced. This is useful to "edit" unit files from scripts:
    
                   $ systemctl edit --drop-in=limits.conf --stdin some-service.service <<EOF
                   [Unit]
                   AllowedCPUs=7,11
                   EOF
    
               Multiple drop-ins may be "edited" in this mode; the same
               contents will be written to all of them.
    
               Added in version 256.
    
           **-H** , **--host=**
               Execute the operation remotely. Specify a hostname, or a
               username and hostname separated by "@", to connect to. The
               hostname may optionally be suffixed by a port ssh is listening
               on, separated by ":", and then a container name, separated by
               "/", which connects directly to a specific container on the
               specified host. This will use SSH to talk to the remote
               machine manager instance. Container names may be enumerated
               with **machinectl -H** _HOST_. Put IPv6 addresses in brackets.
    
           **-M** , **--machine=**
               Execute operation on a local container. Specify a container
               name to connect to, optionally prefixed by a user name to
               connect as and a separating "@" character. If the special
               string ".host" is used in place of the container name, a
               connection to the local system is made (which is useful to
               connect to a specific user's user bus: "--user
               --machine=lennart@.host"). If the "@" syntax is not used, the
               connection is made as root user. If the "@" syntax is used
               either the left hand side or the right hand side may be
               omitted (but not both) in which case the local user name and
               ".host" are implied.
    
           **-C** , **--capsule=**
               Execute operation on a capsule. Specify a capsule name to
               connect to. See capsule@.service(5) for details about
               capsules.
    
               Added in version 256.
    
           **--no-ask-password**
               Do not query the user for authentication for privileged
               operations.
    
           **--no-pager**
               Do not pipe output into a pager.
    
           **--legend=**_BOOL_
               Enable or disable printing of the legend, i.e. column headers
               and the footer with hints. The legend is printed by default,
               unless disabled with **--quiet** or similar.
    
           **-h** , **--help**
               Print a short help text and exit.
    
           **--version**
               Print a short version string and exit.
    


## EXIT STATUS



           On success, 0 is returned, a non-zero failure code otherwise.
    
           **systemctl** uses the return codes defined by LSB, as defined in **LSB**
           **3.0.0******[3].**Table 5. LSB return codes**
           ┌───────┬────────────────────┬────────────────────┐
           │ **Value** │ **Description in LSB** │ **Use in systemd** │
           ├───────┼────────────────────┼────────────────────┤
           │ **0** │ "program is        │ unit is active     │
           │       │ running or service │                    │
           │       │ is OK"             │                    │
           ├───────┼────────────────────┼────────────────────┤
           │ **1** │ "program is dead   │ unit _not_ failed    │
           │       │ and /var/run pid   │ (used by           │
           │       │ file exists"       │ **is-failed**)         │
           ├───────┼────────────────────┼────────────────────┤
           │ **2** │ "program is dead   │ unused             │
           │       │ and /var/lock lock │                    │
           │       │ file exists"       │                    │
           ├───────┼────────────────────┼────────────────────┤
           │ **3** │ "program is not    │ unit is not active │
           │       │ running"           │                    │
           ├───────┼────────────────────┼────────────────────┤
           │ **4** │ "program or        │ no such unit       │
           │       │ service status is  │                    │
           │       │ unknown"           │                    │
           └───────┴────────────────────┴────────────────────┘
    
           The mapping of LSB service states to systemd unit states is
           imperfect, so it is better to not rely on those return values but
           to look for specific unit states and substates instead.
    


## ENVIRONMENT



           _$SYSTEMD_EDITOR_
               Editor to use when editing units; overrides _$EDITOR_ and
               _$VISUAL_. If neither _$SYSTEMD_EDITOR_ nor _$EDITOR_ nor _$VISUAL_
               are present or if it is set to an empty string or if their
               execution failed, systemctl will try to execute well known
               editors in this order: **editor**(1), **nano**(1), **vim**(1), **vi**(1).
    
               Added in version 218.
    
           _$SYSTEMD_LOG_LEVEL_
               The maximum log level of emitted messages (messages with a
               higher log level, i.e. less important ones, will be
               suppressed). Takes a comma-separated list of values. A value
               may be either one of (in order of decreasing importance)
               **emerg** , **alert** , **crit** , **err** , **warning** , **notice** , **info** , **debug** , or an
               integer in the range 0...7. See syslog(3) for more
               information. Each value may optionally be prefixed with one of
               **console** , **syslog** , **kmsg** or **journal** followed by a colon to set
               the maximum log level for that specific log target (e.g.
               **SYSTEMD_LOG_LEVEL=debug,console:info** specifies to log at debug
               level except when logging to the console which should be at
               info level). Note that the global maximum log level takes
               priority over any per target maximum log levels.
    
           _$SYSTEMD_LOG_COLOR_
               A boolean. If true, messages written to the tty will be
               colored according to priority.
    
               This setting is only useful when messages are written directly
               to the terminal, because journalctl(1) and other tools that
               display logs will color messages based on the log level on
               their own.
    
           _$SYSTEMD_LOG_TIME_
               A boolean. If true, console log messages will be prefixed with
               a timestamp.
    
               This setting is only useful when messages are written directly
               to the terminal or a file, because journalctl(1) and other
               tools that display logs will attach timestamps based on the
               entry metadata on their own.
    
           _$SYSTEMD_LOG_LOCATION_
               A boolean. If true, messages will be prefixed with a filename
               and line number in the source code where the message
               originates.
    
               Note that the log location is often attached as metadata to
               journal entries anyway. Including it directly in the message
               text can nevertheless be convenient when debugging programs.
    
           _$SYSTEMD_LOG_TARGET_
               The destination for log messages. One of **console**(log to the
               attached tty), **console-prefixed**(log to the attached tty but
               with prefixes encoding the log level and "facility", see
               syslog(3), **kmsg**(log to the kernel circular log buffer),
               **journal**(log to the journal), **journal-or-kmsg**(log to the
               journal if available, and to kmsg otherwise), **auto**(determine
               the appropriate log target automatically, the default), **null**
               (disable log output).
    
           _$SYSTEMD_PAGER_ , _$PAGER_
               Pager to use when **--no-pager** is not given.  _$SYSTEMD_PAGER_ is
               used if set; otherwise _$PAGER_ is used. If neither
               _$SYSTEMD_PAGER_ nor _$PAGER_ are set, a set of well-known pager
               implementations is tried in turn, including less(1) and
               more(1), until one is found. If no pager implementation is
               discovered, no pager is invoked. Setting those environment
               variables to an empty string or the value "cat" is equivalent
               to passing **--no-pager**.
    
               Note: if _$SYSTEMD_PAGERSECURE_ is not set, _$SYSTEMD_PAGER_ and
               _$PAGER_ can only be used to disable the pager (with "cat" or
               ""), and are otherwise ignored.
    
           _$SYSTEMD_LESS_
               Override the options passed to **less**(by default "FRSXMK").
    
               Users might want to change two options in particular:
    
               **K**
                   This option instructs the pager to exit immediately when
                   Ctrl+C is pressed. To allow **less** to handle Ctrl+C itself
                   to switch back to the pager command prompt, unset this
                   option.
    
                   If the value of _$SYSTEMD_LESS_ does not include "K", and
                   the pager that is invoked is **less** , Ctrl+C will be ignored
                   by the executable, and needs to be handled by the pager.
    
               **X**
                   This option instructs the pager to not send termcap
                   initialization and deinitialization strings to the
                   terminal. It is set by default to allow command output to
                   remain visible in the terminal even after the pager exits.
                   Nevertheless, this prevents some pager functionality from
                   working, in particular paged output cannot be scrolled
                   with the mouse.
    
               Note that setting the regular _$LESS_ environment variable has
               no effect for **less** invocations by systemd tools.
    
               See less(1) for more discussion.
    
           _$SYSTEMD_LESSCHARSET_
               Override the charset passed to **less**(by default "utf-8", if
               the invoking terminal is determined to be UTF-8 compatible).
    
               Note that setting the regular _$LESSCHARSET_ environment
               variable has no effect for **less** invocations by systemd tools.
    
           _$SYSTEMD_PAGERSECURE_
               Common pager commands like less(1), in addition to "paging",
               i.e. scrolling through the output, support opening of or
               writing to other files and running arbitrary shell commands.
               When commands are invoked with elevated privileges, for
               example under sudo(8) or **pkexec**(1), the pager becomes a
               security boundary. Care must be taken that only programs with
               strictly limited functionality are used as pagers, and
               unintended interactive features like opening or creation of
               new files or starting of subprocesses are not allowed. "Secure
               mode" for the pager may be enabled as described below, _if the_
               _pager supports that_ (most pagers are not written in a way that
               takes this into consideration). It is recommended to either
               explicitly enable "secure mode" or to completely disable the
               pager using **--no-pager** or _PAGER=cat_ when allowing untrusted
               users to execute commands with elevated privileges.
    
               This option takes a boolean argument. When set to true, the
               "secure mode" of the pager is enabled. In "secure mode",
               **LESSSECURE=1** will be set when invoking the pager, which
               instructs the pager to disable commands that open or create
               new files or start new subprocesses. Currently only less(1) is
               known to understand this variable and implement "secure mode".
    
               When set to false, no limitation is placed on the pager.
               Setting _SYSTEMD_PAGERSECURE=0_ or not removing it from the
               inherited environment may allow the user to invoke arbitrary
               commands.
    
               When _$SYSTEMD_PAGERSECURE_ is not set, systemd tools attempt to
               automatically figure out if "secure mode" should be enabled
               and whether the pager supports it. "Secure mode" is enabled if
               the effective UID is not the same as the owner of the login
               session, see geteuid(2) and sd_pid_get_owner_uid(3), or when
               running under sudo(8) or similar tools (_$SUDO_UID_ is set [4]).
               In those cases, _SYSTEMD_PAGERSECURE=1_ will be set and pagers
               which are not known to implement "secure mode" will not be
               used at all. Note that this autodetection only covers the most
               common mechanisms to elevate privileges and is intended as
               convenience. It is recommended to explicitly set
               _$SYSTEMD_PAGERSECURE_ or disable the pager.
    
               Note that if the _$SYSTEMD_PAGER_ or _$PAGER_ variables are to be
               honoured, other than to disable the pager,
               _$SYSTEMD_PAGERSECURE_ must be set too.
    
           _$SYSTEMD_COLORS_
               Takes a boolean argument. When true, **systemd** and related
               utilities will use colors in their output, otherwise the
               output will be monochrome. Additionally, the variable can take
               one of the following special values: "16", "256" to restrict
               the use of colors to the base 16 or 256 ANSI colors,
               respectively. This can be specified to override the automatic
               decision based on _$TERM_ and what the console is connected to.
    
           _$SYSTEMD_URLIFY_
               The value must be a boolean. Controls whether clickable links
               should be generated in the output for terminal emulators
               supporting this. This can be specified to override the
               decision that **systemd** makes based on _$TERM_ and other
               conditions.
    


## NOTES



            1. Boot Loader Specification
               https://uapi-group.org/specifications/specs/boot_loader_specification
    
            2. Discoverable Partitions Specification
               https://uapi-group.org/specifications/specs/discoverable_partitions_specification
    
            3. LSB 3.0.0
               http://refspecs.linuxbase.org/LSB_3.0.0/LSB-PDA/LSB-PDA/iniscrptact.html
    
            4. It is recommended for other tools to set and check _$SUDO_UID_
               as appropriate, treating it is a common interface.
    


* * *