systemctl

SYSTEMCTL(1)                        systemctl                       SYSTEMCTL(1)



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
       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 PATTERNs 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.

           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 active, reloading, inactive, failed, activating,
           deactivating. 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 maybe be used to display the current set of possible values.

           This is the default command.

       list-sockets [PATTERN...]
           List socket units currently in memory, ordered by listening address.
           If one or more PATTERNs are specified, only socket units matching one
           of them are shown. Produces output similar to

               LISTEN           UNIT                        ACTIVATES
               /dev/initctl     systemd-initctl.socket      systemd-initctl.service
               ...
               [::]:22          sshd.socket                 sshd.service
               kobject-uevent 1 systemd-udevd-kernel.socket systemd-udevd.service

               5 sockets listed.

           Note: because the addresses might contains spaces, this output is not
           suitable for programmatic consumption.

           Also see --show-types, --all, and --state=.

       list-timers [PATTERN...]
           List timer units currently in memory, ordered by the time they elapse
           next. If one or more PATTERNs are specified, only units matching one
           of them are shown. Produces output similar to

               NEXT                         LEFT          LAST                         PASSED     UNIT                         ACTIVATES
               n/a                          n/a           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=.

       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.

       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.

       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.

       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 is allowed only on units where AllowIsolate= is
           enabled. See systemd.unit(5) for details.

       kill PATTERN...
           Send a signal to one or more processes of the unit. Use --kill-who=
           to select which process to kill. Use --signal= to select the signal
           to send.

       clean PATTERN...
           Remove the configuration, state, cache, logs or runtime 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. 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, both the cache and runtime data are removed (as these two
           types of data are generally redundant and reproducible on the next
           invocation of the unit).

       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 won't 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.

       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.

       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 are in a "failed" state.
           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 state to standard output.

       status [PATTERN...|PID...]]
           Show terse runtime status information about one or more units,
           followed by most recent log data from the journal. If no units are
           specified, show system status. If combined with --all, also show the
           status of all units (subject to limitations specified with -t). If a
           PID is passed, show information about the unit the process belongs
           to.

           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.

           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; vendor 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. White indicates an "inactive" or "deactivating"
           state. Red indicates a "failed" or "error" state and green indicates
           an "active", "reloading" or "activating" state.

           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 commands start at boot. 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 may not match the system
           manager's understanding of these units if any unit files were updated
           on disk and the daemon-reload command wasn't issued since.

       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=

       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.

       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.

       list-dependencies [UNIT...]
           Shows units required and wanted by the specified units. This
           recursively lists units following the Requires=, Requisite=,
           ConsistsOf=, Wants=, BindsTo= dependencies. If no units are
           specified, default.target 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 won't list the dependencies declared by units currently
           not loaded.

   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 PATTERNs
           are specified, only unit files whose name matches one of them are
           shown (patterns matching unit file system paths are not supported).

       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.

           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.

           This command honors --system, --user, --runtime and --global in a
           similar way as enable.

       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.

       preset UNIT...
           Reset the enable/disable status 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). For more information on the concept of presets,
           please consult the Preset[1] document.

       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.

       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 1.  is-enabled output
           ┌──────────────────┬─────────────────────────┬───────────┐
           │Name              Description             Exit Code │
           ├──────────────────┼─────────────────────────┼───────────┤
           │"enabled"         │ Enabled via .wants/,    │           │
           ├──────────────────┤ .requires/ or Alias=    │           │
           │"enabled-runtime" │ symlinks                │           │
           │                  │ (permanently in         │ 0         │
           │                  │ /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.                │           │
           └──────────────────┴─────────────────────────┴───────────┘

       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.

       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.

       link PATH...
           Link a unit file that is not in the unit file search paths 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).

       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.

       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.

       edit UNIT...
           Edit a drop-in snippet or a whole replacement file if --full is
           specified, to extend or override the specified unit.

           Depending on whether --system (the default), --user, or --global is
           specified, this command creates a drop-in file for each unit either
           for the system, for the calling user, or for all futures logins of
           all users. Then, 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.

           If --full is specified, this will copy the original units instead of
           creating drop-in files.

           If --force is specified and any units do not already exist, new unit
           files will be opened for editing.

           If --runtime is specified, the changes will be made temporarily in
           /run and they will be lost on the next reboot.

           If the temporary file is empty upon exit, the modification of the
           related unit is canceled.

           After the units have been edited, systemd configuration is reloaded
           (in a way that is equivalent to daemon-reload).

           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.

       get-default
           Return the default target to boot into. This returns the target unit
           name default.target is aliased (symlinked) to.

       set-default TARGET
           Set the default target to boot into. This sets (symlinks) the
           default.target alias to the given target unit.

   Machine Commands
       list-machines [PATTERN...]
           List the host and all running local containers with their state. If
           one or more PATTERNs are specified, only containers matching one of
           them are shown.

   Job Commands
       list-jobs [PATTERN...]
           List jobs that are in progress. If one or more PATTERNs 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.

       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.

   Environment Commands
       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 straight-forward 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).

       set-environment VARIABLE=VALUE...
           Set one or more systemd manager environment variables, as specified
           on the command line.

       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.

       import-environment [VARIABLE...]
           Import all, one or more environment variables set on the client into
           the systemd manager environment block. If no arguments are passed,
           the entire environment block is imported. Otherwise, a list of one or
           more environment variable names should be passed, whose client-side
           values are then imported into the manager's environment block.

   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)).

       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)).

       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.

   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 2. is-system-running output
           ┌─────────────┬──────────────────────┬───────────┐
           │Name         Description          Exit Code │
           ├─────────────┼──────────────────────┼───────────┤
           │initializing │ Early bootup, before │ > 0       │
           │             │ basic.target is      │           │
           │             │ reached or the       │           │
           │             │ maintenance state    │           │
           │             │ entered.             │           │
           ├─────────────┼──────────────────────┼───────────┤
           │starting     │ Late bootup, before  │ > 0       │
           │             │ the job queue        │           │
           │             │ becomes idle for the │           │
           │             │ first time, or one   │           │
           │             │ of the rescue        │           │
           │             │ targets are reached. │           │
           ├─────────────┼──────────────────────┼───────────┤
           │running      │ The system is fully  │ 0         │
           │             │ 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. │           │
           └─────────────┴──────────────────────┴───────────┘

       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.

       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.

           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 powering
           off. 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 power-off 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.

       reboot
           Shut down and reboot the system. This is 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 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 reboot.
           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 reboot 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 the switch --reboot-argument= is given, it will be passed as the
           optional argument to the reboot(2) system call.

       kexec
           Shut down and reboot the system via kexec. This is equivalent to
           systemctl start kexec.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.

           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 reboot.

       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.

       switch-root ROOT [INIT]
           Switches to a different root directory and executes a new system
           manager process below it. This is intended for usage in initial RAM
           disks ("initrd"), and will transition from the initrd's system
           manager process (a.k.a. "init" process) to the main system manager
           process which is loaded from the actual host volume. This call takes
           two arguments: the directory that is to become the new root
           directory, and the path to the new system manager binary below it to
           execute as PID 1. If the latter is omitted or the empty string, a
           systemd binary will automatically be searched for and used as init.
           If the system manager path is omitted, 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.

       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.

       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.

       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.

       suspend-then-hibernate
           Suspend the system and hibernate it after the delay specified in
           systemd-sleep.conf. 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.

   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 aren't 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 should be a comma-separated list of unit types such as
           service and socket.

           If one of the arguments is a unit type, when listing units, limit
           display to certain unit types. Otherwise, units of all types will be
           shown.

           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 should be a comma-separated list of unit LOAD, SUB, or
           ACTIVE states. When listing units, show only those in the specified
           states. Use --state=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.

       -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. Those properties are documented 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=.

       -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 (":").

       --reverse
           Show reverse dependencies between units with list-dependencies, i.e.
           follow dependencies of type WantedBy=, RequiredBy=, PartOf=,
           BoundBy=, instead of Wants= and similar.

       --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.

       --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.

       --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.

       -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.

       --show-types
           When showing sockets, show the type of the socket.

       --job-mode=
           When queuing a new job, this option controls how to deal with already
           queued jobs. It takes one of "fail", "replace",
           "replace-irreversibly", "isolate", "ignore-dependencies",
           "ignore-requirements", "flush", or "triggering". Defaults to
           "replace", except when the isolate command is used which implies the
           "isolate" job mode.

           If "fail" is specified and a requested operation 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 "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.

       -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.

       --fail
           Shorthand for --job-mode=fail.

           When used with the kill command, if no units were killed, the
           operation results in an error.

       -i, --ignore-inhibitors
           When system shutdown or a sleep state is requested, ignore inhibitor
           locks. Applications can establish inhibitor locks to avoid that
           certain important operations (such as CD burning or suchlike) are
           interrupted by system shutdown or a sleep state. Any user may take
           these locks and privileged users may override these locks. If any
           locks are taken, shutdown and sleep state requests will normally fail
           (unless privileged) and a list of active locks is printed. However,
           if --ignore-inhibitors is specified, the established locks are
           ignored and not shown, and the operation attempted anyway, possibly
           requiring additional privileges.

       --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.

       -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.

       --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
           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.

       --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.

       --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 and disable, do not implicitly reload daemon
           configuration after executing the changes.

       --no-ask-password
           When used with start and related commands, disables asking for
           passwords. Background services may require input of a password or
           passphrase string, for example to unlock system hard disks or
           cryptographic certificates. Unless this option is specified and the
           command is invoked from a terminal, systemctl will query the user on
           the terminal for the necessary secrets. Use this option to switch
           this behavior off. In this case, the password must be supplied by
           some other means (for example graphical password agents) or the
           service might fail. This also disables querying the user for
           authentication for privileged operations.

       --kill-who=
           When used with kill, choose which processes to send a signal to. Must
           be one of main, control or all to select whether to kill only the
           main process, the control process 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. 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.

       -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.

       --what=
           Select what type of per-unit resources to remove when the clean
           command is invoked, see below. Takes one of configuration, state,
           cache, logs, runtime 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 five resource types. If this option is not
           specified defaults to the combination of cache and runtime, i.e. the
           two kinds of resources that are generally considered to be redundant
           and can be reconstructed on next invocation.

       -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 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.

       --now
           When used with enable, the units will also be started. When used with
           disable or mask, the units will also be stopped. The start or stop
           operation is only carried out when the respective enable or disable
           operation has been successful.

       --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.

       --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.

       -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 command, indicate to the system's firmware
           to reboot into the firmware setup interface. Note that this
           functionality is not available on all systems.

       --boot-loader-menu=
           When used with the reboot 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.

       --boot-loader-entry=
           When used with the reboot 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.

       --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.

       --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.

       -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.

       --no-pager
           Do not pipe output into a pager.

       --no-legend
           Do not print the legend, i.e. column headers and the footer with
           hints.

       -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[2].

       Table 3. LSB return codes
       ┌──────┬──────────────────────┬─────────────────────┐
       │Value Description in LSB   Use in systemd      │
       ├──────┼──────────────────────┼─────────────────────┤
       │0     │ "program is running  │ unit is active      │
       │      │ or service is OK"    │                     │
       ├──────┼──────────────────────┼─────────────────────┤
       │1     │ "program is dead and │ unit not failed     │
       │      │ /var/run pid file    │ (used by is-failed) │
       │      │ exists"              │                     │
       ├──────┼──────────────────────┼─────────────────────┤
       │2     │ "program is dead and │ unused              │
       │      │ /var/lock lock file  │                     │
       │      │ exists"              │                     │
       ├──────┼──────────────────────┼─────────────────────┤
       │3     │ "program is not      │ unit is not active  │
       │      │ running"             │                     │
       ├──────┼──────────────────────┼─────────────────────┤
       │4     │ "program or service  │ no such unit        │
       │      │ 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).

       $SYSTEMD_PAGER
           Pager to use when --no-pager is not given; overrides $PAGER. If
           neither $SYSTEMD_PAGER nor $PAGER are set, a set of well-known pager
           implementations are tried in turn, including less(1) and more(1),
           until one is found. If no pager implementation is discovered no pager
           is invoked. Setting this environment variable to an empty string or
           the value "cat" is equivalent to passing --no-pager.

       $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.

           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).

       $SYSTEMD_COLORS
           The value must be a boolean. Controls whether colorized output should
           be generated. This can be specified to override the decision that
           systemd makes 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.

SEE ALSO
       systemd(1), journalctl(1), loginctl(1), machinectl(1), systemd.unit(5),
       systemd.resource-control(5), systemd.special(7), wall(1),
       systemd.preset(5), systemd.generator(7), glob(7)

NOTES
        1. Preset
           https://www.freedesktop.org/wiki/Software/systemd/Preset

        2. LSB 3.0.0
           http://refspecs.linuxbase.org/LSB_3.0.0/LSB-PDA/LSB-PDA/iniscrptact.html



systemd 246                                                         SYSTEMCTL(1)