SYSTEMCTL(1)                       systemctl                      SYSTEMCTL(1)



NAME
       systemctl - Control the systemd system and service manager

SYNOPSIS
       systemctl [OPTIONS...] COMMAND [NAME...]

DESCRIPTION
       systemctl may be used to introspect and control the state of the
       systemd(1) system and service manager.

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 specified
           states.

       -p, --property=
           When showing unit/job/manager properties with the show command,
           limit display to certain properties as specified as argument. If
           not specified, all set properties are shown. The argument should be
           a comma-separated list of property names, such as "MainPID". If
           specified more than once, all properties with the specified names
           are shown.

       -a, --all
           When listing units, show all loaded units, regardless of their
           state, including inactive units. When showing unit/job/manager
           properties, show all properties regardless whether they are set or
           not.

           To list all units installed on the system, use the list-unit-files
           command instead.

       -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. units with dependencies of type Wants= or Requires= on the
           given unit.

       --after
           With list-dependencies, show the units that are ordered before the
           specified unit. In other words, list the units that are in the
           After= directive of the specified unit, have the specified unit in
           their Before= directive, or are otherwise implicit dependencies of
           the specified unit.

       --before
           With list-dependencies, show the units that are ordered after the
           specified unit. In other words, list the units that are in the
           Before= directive of the specified unit, have the specified unit in
           their After= directive, or otherwise depend on the specified unit.

       -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.

       --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.

           "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 honoured.

       -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.

       -q, --quiet
           Suppress output to standard output in snapshot, is-active,
           is-failed, is-enabled, is-system-running, enable and disable.

       --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 it is completed. By passing this
           argument, it is only verified and enqueued.

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

       --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, 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 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, 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.

       --root=
           When used with enable/disable/is-enabled (and related commands),
           use alternative root path when looking for unit files.

       --runtime
           When used with enable, disable, (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".

       --plain
           When used with list-dependencies, the output is printed as a list
           instead of a tree.

       -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.

       -h, --help
           Print a short help text and exit.

       --version
           Print a short version string and exit.

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

COMMANDS
       The following commands are understood:

   Unit Commands
       list-units [PATTERN...]
           List known units (subject to limitations specified with -t). If one
           or more PATTERNs are specified, only units matching one of them are
           shown.

           This is the default command.

       list-sockets [PATTERN...]
           List socket units 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.

           See also the options --show-types, --all, and --failed.

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

           See also the options --all and --failed.

       start PATTERN...
           Start (activate) one or more units specified on the command line.

           Note that glob patterns operate on a list of currently loaded
           units. Units which are not active and are not in a failed state
           usually are not loaded, and would 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.

       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 or load
           commands.

       restart PATTERN...
           Restart one or more units specified on the command line. If the
           units are not running yet, they will be started.

       try-restart PATTERN...
           Restart one or more units specified on the command line if the
           units are running. This does nothing if units are not running. Note
           that, for compatibility with Red Hat init scripts, condrestart is
           equivalent to this command.

       reload-or-restart PATTERN...
           Reload one or more units if they support it. If not, restart them
           instead. If the units are not running yet, they will be started.

       reload-or-try-restart PATTERN...
           Reload one or more units if they support it. If not, restart them
           instead. This does nothing if the units are not running. Note that,
           for compatibility with SysV init scripts, force-reload is
           equivalent to this command.

       isolate NAME
           Start the unit specified on the command line and its dependencies
           and stop all others.

           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 changes 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.

       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 is
           shown, and if a job id is specified, properties of the job is
           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.

       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.

       set-property NAME ASSIGNMENT...
           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 instantly, 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

           Note that this command allows changing multiple properties at the
           same time, which is preferable over setting them individually. Like
           unit file configuration settings, assigning the empty list to list
           parameters will reset the list.

       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 restarted or reset with this
           command.

       list-dependencies NAME
           Shows required and wanted units of the specified unit. If no unit
           is specified, default.target is implied. Target units are
           recursively expanded. When --all is passed, all other units are
           recursively expanded as well.

   Unit File Commands
       list-unit-files [PATTERN...]
           List installed unit files. If one or more PATTERNs are specified,
           only units whose filename (just the last component of the path)
           matches one of them are shown.

       enable NAME...
           Enable one or more unit files or unit file instances, as specified
           on the command line. This will create a number of symlinks as
           encoded in the "[Install]" sections of the unit files. After the
           symlinks have been created, the systemd configuration is reloaded
           (in a way that is equivalent to daemon-reload) 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, a separate start command must be invoked for the
           unit. Also note that in case of instance enablement, symlinks named
           the same as instances are created in the install location, however
           they all point to the same template unit file.

           This command will print the actions executed. This output may be
           suppressed by passing --quiet.

           Note that this operation creates only the suggested symlinks for
           the units. While this command is the recommended way to manipulate
           the unit configuration directory, the administrator is free to make
           additional changes manually by placing or removing symlinks in the
           directory. This is particularly useful to create configurations
           that deviate from the suggested default installation. In this case,
           the administrator must make sure to invoke daemon-reload manually
           as necessary 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, or only this boot. Note that in the last case,
           no systemd daemon configuration is reloaded.

       disable NAME...
           Disables one or more units. This removes all symlinks to the
           specified unit files from the unit configuration directory, and
           hence undoes the changes made by enable. Note however that this
           removes all symlinks to the unit files (i.e. including manual
           additions), not just those actually created by enable. This call
           implicitly reloads the systemd daemon configuration after
           completing the disabling of the units. Note that this command does
           not implicitly stop the units that are being disabled. If this is
           desired, an additional stop command should be executed afterwards.

           This command will print the actions executed. This output may be
           suppressed by passing --quiet.

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

       is-enabled NAME...
           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.

           Table 1.  is-enabled output
           +------------------+---------------------+--------------+
           |Printed string    | Meaning             | Return value |
           +------------------+---------------------+--------------+
           |"enabled"         | Enabled through a   |              |
           +------------------+ symlink in .wants   |              |
           |"enabled-runtime" | directory           | 0            |
           |                  | (permanently or     |              |
           |                  | just in /run)       |              |
           +------------------+---------------------+--------------+
           |"linked"          | Made available      |              |
           +------------------+ through a symlink   |              |
           |"linked-runtime"  | to the unit file    | 1            |
           |                  | (permanently or     |              |
           |                  | just in /run)       |              |
           +------------------+---------------------+--------------+
           |"masked"          | Disabled entirely   |              |
           +------------------+ (permanently or     | 1            |
           |"masked-runtime"  | just in /run)       |              |
           +------------------+---------------------+--------------+
           |"static"          | Unit is not         | 0            |
           |                  | enabled, but has no |              |
           |                  | provisions for      |              |
           |                  | enabling in         |              |
           |                  | [Install] section   |              |
           +------------------+---------------------+--------------+
           |"disabled"        | Unit is not enabled | 1            |
           +------------------+---------------------+--------------+

       reenable NAME...
           Reenable one or more unit files, as specified on the command line.
           This is a combination of disable and enable and is useful to reset
           the symlinks a unit is enabled with to the defaults configured in
           the "[Install]" section of the unit file.

       preset NAME...
           Reset one or more unit files, as specified on the command line, to
           the defaults configured in the preset policy files. This has the
           same effect as 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.

           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.

       mask NAME...
           Mask one or more unit files, as specified on the command line. This
           will link these units 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 manual activation. Use
           this option with care. This honors the --runtime option to only
           mask temporarily until the next reboot of the system.

       unmask NAME...
           Unmask one or more unit files, as specified on the command line.
           This will undo the effect of mask.

       link FILENAME...
           Link a unit file that is not in the unit file search paths into the
           unit file search path. This requires an absolute path to a unit
           file. The effect of this can be undone with disable. The effect of
           this command is that a unit file is available for start and other
           commands although it is not installed directly in the unit search
           path.

       get-default
           Get the default target specified via default.target link.

       set-default NAME
           Set the default target to boot into. Command links default.target
           to the given 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.

       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.

   Snapshot Commands
       snapshot [NAME]
           Create a snapshot. If a snapshot name is specified, the new
           snapshot will be named after it. If none is specified, an automatic
           snapshot name is generated. In either case, the snapshot name used
           is printed to standard output, unless --quiet is specified.

           A snapshot refers to a saved state of the systemd manager. It is
           implemented itself as a unit that is generated dynamically with
           this command and has dependencies on all units active at the time.
           At a later time, the user may return to this state by using the
           isolate command on the snapshot unit.

           Snapshots are only useful for saving and restoring which units are
           running or are stopped, they do not save/restore any other state.
           Snapshots are dynamic and lost on reboot.

       delete PATTERN...
           Remove a snapshot previously created with snapshot.

   Environment Commands
       show-environment
           Dump the systemd manager environment block. The environment block
           will be dumped in straight-forward form suitable for sourcing into
           a shell script. This environment block will be passed to all
           processes the manager spawns.

       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 systemd manager configuration. This will reload all unit
           files and recreate the entire dependency tree. While the daemon is
           being reloaded, all sockets systemd listens on on behalf of user
           configuration will stay accessible.

           This command should not be confused with the load or reload
           commands.

       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 running. This returns success when the
           system is fully up and running, meaning not in startup, shutdown or
           maintainance mode. Failure is returned otherwise. In addition, the
           current state is printed in a short string to standard output. Use
           --quiet to suppress output of this state string.

       default
           Enter default mode. This is mostly equivalent to isolate
           default.target.

       rescue
           Enter rescue mode. This is mostly equivalent to isolate
           rescue.target, but also prints a wall message to all users.

       emergency
           Enter emergency mode. This is mostly equivalent to isolate
           emergency.target, but also prints a wall message to all users.

       halt
           Shut down and halt the system. This is mostly equivalent to start
           halt.target --irreversible, but also prints a wall message to all
           users. 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.

       poweroff
           Shut down and power-off the system. This is mostly equivalent to
           start poweroff.target --irreversible, but also prints a wall
           message to all users. 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.

       reboot [arg]
           Shut down and reboot the system. This is mostly equivalent to start
           reboot.target --irreversible, but also prints a wall message to all
           users. 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.

           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 mostly
           equivalent to start kexec.target --irreversible, but also prints a
           wall message to all users. 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
           Ask the systemd manager to quit. This is only supported for user
           service managers (i.e. in conjunction with the --user option) and
           will fail otherwise.

       suspend
           Suspend the system. This will trigger activation of the special
           suspend.target target.

       hibernate
           Hibernate the system. This will trigger activation of the special
           hibernate.target target.

       hybrid-sleep
           Hibernate and suspend the system. This will trigger activation of
           the special hybrid-sleep.target target.

       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. This call takes two arguments: the directory that is to
           become the new root directory, and the path to the new system
           manager binary below it to execute as PID 1. If the latter is
           omitted or the empty string, a systemd binary will automatically be
           searched for and used as init. If the system manager path is
           omitted or equal to the empty string, the state of the initrd's
           system manager process is passed to the main system manager, which
           allows later introspection of the state of the services involved in
           the initrd boot.

   Parameter Syntax
       Unit commands listed above take either a single unit name (designated
       as NAME), 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, 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 snapshot-11

       and

           # systemctl isolate snapshot-11.snapshot

       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 currently
       loaded units; 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 names of currently loaded units, and
       patterns which do not match anything are silently skipped. For example:

           # systemctl stop sshd@*.service

       will stop all sshd@.service instances.

       For unit file commands, the specified NAME should be the full name of
       the unit file, 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_PAGER
           Pager to use when --no-pager is not given; overrides $PAGER.
           Setting this to an empty string or the value "cat" is equivalent to
           passing --no-pager.

       $SYSTEMD_LESS
           Override the default options passed to less ("FRSXMK").

SEE ALSO
       systemd(1), systemadm(1), journalctl(1), loginctl(1), systemd.unit(5),
       systemd.resource-management(5), systemd.special(7), wall(1),
       systemd.preset(5)glob(7)

NOTES
        1. Preset
           http://freedesktop.org/wiki/Software/systemd/Preset



systemd 215                                                       SYSTEMCTL(1)
