systemctl - Control the systemd system and service manager



  • 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" 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, 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. 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.
    
           --before
    	   With list-dependencies, show the units that are ordered after the specified unit. In
    	   other words, recursively list units following the Before= dependency.
    
           -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.
    
           --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.
    
           -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.
    
           --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.
    
           --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.
    
           --message=
    	   When used with halt, poweroff, reboot or kexec, 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 an alternate root
    	   path when looking for unit files.
    
           --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 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 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 --state=.
    
           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 --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 currently loaded units.
    	   Units which are not active and are not in a failed state usually are not loaded, 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...
    	   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.
    
           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.
    
           try-reload-or-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.
    
           isolate NAME
    	   Start the unit specified on the command line and its dependencies and stop all others.
    	   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.
    
           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
    
    	   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 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 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 installed unit files and their enablement state (as reported by is-enabled). 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, either --now should be
    	   used together with this command, or an additional 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.
    
    	   Using enable on masked units results in an error.
    
           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, either --now should be used together with this command, or 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.
    
           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.
    
           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
    	   ┌──────────────────┬──────────────────────────┬───────────┐
    	   │Name	      │ Description		 │ Exit Code │
    	   ├──────────────────┼──────────────────────────┼───────────┤
    	   │"enabled"	      │ Enabled via .wants/,	 │	     │
    	   ├──────────────────┤ .requires/ or alias	 │	     │
    	   │"enabled-runtime" │ symlinks (permanently in │ 0	     │
    	   │		      │ /etc/systemd/system/, or │	     │
    	   │		      │ transiently in		 │	     │
    	   │		      │ /run/systemd/system/).	 │	     │
    	   ├──────────────────┼──────────────────────────┼───────────┤
    	   │"linked"	      │ Made available through	 │	     │
    	   ├──────────────────┤ one or more symlinks 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]"	 │	     │
    	   │		      │ section.		 │	     │
    	   ├──────────────────┼──────────────────────────┼───────────┤
    	   │"indirect"	      │ The unit file itself is  │ 0	     │
    	   │		      │ not enabled, but it has  │	     │
    	   │		      │ a non-empty Also=	 │	     │
    	   │		      │ setting in the		 │	     │
    	   │		      │ "[Install]" section,	 │	     │
    	   │		      │ listing other unit files │	     │
    	   │		      │ that might be enabled.	 │	     │
    	   ├──────────────────┼──────────────────────────┼───────────┤
    	   │"disabled"	      │ Unit file is not	 │ > 0	     │
    	   │		      │ enabled, but contains an │	     │
    	   │		      │ "[Install]" section with │	     │
    	   │		      │ installation		 │	     │
    	   │		      │ instructions.		 │	     │
    	   ├──────────────────┼──────────────────────────┼───────────┤
    	   │"bad"	      │ Unit file is invalid or  │ > 0	     │
    	   │		      │ 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 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 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 can be
    	   used to ensure that the units are also stopped.
    
           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.
    
           add-wants TARGET NAME..., add-requires TARGET NAME...
    	   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 NAME...
    	   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 --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 NAME
    	   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.
    
           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. 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 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
    	   ┌─────────────┬──────────────────────────┬───────────┐
    	   │Name	 │ Description		    │ Exit 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 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
    	   --job-mode=replace-irreversibly, 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
    	   --job-mode=replace-irreversibly, 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
    	   --job-mode=replace-irreversibly, 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 --job-mode=replace-irreversibly, 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 [EXIT_CODE]
    	   Ask the systemd 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.
    
    	   The systemd manager can exit with a non-zero exit code if the optional argument
    	   EXIT_CODE is given.
    
           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.
    
           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.
    
       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 (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
           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
           primary names of currently loaded units, and patterns which do not match anything are
           silently skipped. For example:
    
    	   # systemctl stop sshd@*.service
    
           will stop all [email protected] instances. Note that alias names of units, and units that
           aren't loaded are not considered for glob expansion.
    
           For unit file commands, the specified NAME 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. 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), 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
    	   http://freedesktop.org/wiki/Software/systemd/Preset
    
    systemd 229									     SYSTEMCTL(1)
    

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