Provided by: systemd_239-7ubuntu10_amd64 bug

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.

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.

       -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).

       -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.

       -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 "=".

       --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" or "flush". 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.

       --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 (regardless of
           whether privileged or not) and a list of active locks is printed. However, if
           --ignore-inhibitors is specified, the locks are ignored and not printed, 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, 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".

       --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 /bin/mount and /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.

       -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. 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 boot into
           setup mode. Note that this is currently only supported on some EFI systems and only if
           the system was booted in EFI mode.

       --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
           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.

       -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.

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 active running 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 glob patterns operate on the set of primary 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.

       stop PATTERN...
           Stop (deactivate) one or more units specified on the command line.

       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 FileDescriptoreStoreMax= 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 is similar to changing the runlevel in a traditional init system. The isolate
           command will immediately stop processes that are not enabled in the new unit, 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.

       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 (/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 not 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 by the system
           and service manager.

       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 CPUShares=777

           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. Like with unit file configuration settings,
           assigning an empty list will reset the property.

       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.

       list-dependencies [UNIT]
           Shows units required and wanted by the specified unit. This recursively lists units
           following the Requires=, Requisite=, ConsistsOf=, Wants=, BindsTo= dependencies. If no
           unit is 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.

   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
           ┌──────────────────┬──────────────────────────┬───────────┐
           │NameDescriptionExit 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 to  │           │
           │"linked-runtime"  │ 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.             │           │
           ├──────────────────┼──────────────────────────┼───────────┤
           │"masked"          │ Completely disabled, so  │           │
           ├──────────────────┤ that any start operation │           │
           │"masked-runtime"  │ on it fails (permanently │ > 0       │
           │                  │ in /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 │           │
           │                  │ file, 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 invalid │ > 0       │
           │                  │ 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 Lifecycle 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.

   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.

           Table 2. is-system-running output
           ┌─────────────┬──────────────────────────┬───────────┐
           │NameDescriptionExit Code │
           ├─────────────┼──────────────────────────┼───────────┤
           │initializing │ Early bootup, before     │ > 0       │
           │             │ basic.target is reached  │           │
           │             │ or the maintenance state │           │
           │             │ entered.                 │           │
           ├─────────────┼──────────────────────────┼───────────┤
           │starting     │ Late bootup, before the  │ > 0       │
           │             │ 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 emergency  │ > 0       │
           │             │ target is active.        │           │
           ├─────────────┼──────────────────────────┼───────────┤
           │stopping     │ The manager is shutting  │ > 0       │
           │             │ 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 state    │ > 0       │
           │             │ 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 [arg]
           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 optional argument arg is given, it will be passed as the optional argument to
           the reboot(2) system call. 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.

       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.

   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

EXIT STATUS

       On success, 0 is returned, a non-zero failure code otherwise.

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").

       $SYSTEMD_LESSCHARSET
           Override the charset passed to less (by default "utf-8", if the invoking terminal is
           determined to be UTF-8 compatible).

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