systemctl(1) - 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 specified
    	   states. Use --state=failed to show only failed units.
    
           -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=,
    	   RequiredByOverrridable=, 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.
    
    	   Also, show installation targets in the output of is-enabled.
    
           --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.
    
           --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.
    
           --no-reload
    	   When used with enable and disable, do not implicitly reload daemon
    	   configuration after executing the changes.
    
           --no-ask-password
    	   When used with start and related commands, disables asking for
    	   passwords. Background services may require input of a password or
    	   passphrase string, for example to unlock system hard disks or
    	   cryptographic certificates. Unless this option is specified and the
    	   command is invoked from a terminal, systemctl will query the user
    	   on the terminal for the necessary secrets. Use this option to
    	   switch this behavior off. In this case, the password must be
    	   supplied by some other means (for example graphical password
    	   agents) or the service might fail. This also disables querying the
    	   user for authentication for privileged operations.
    
           --kill-who=
    	   When used with kill, choose which processes to send a signal to.
    	   Must be one of main, control or all to select whether to kill only
    	   the main process, the control process or all processes of the unit.
    	   The main process of the unit is the one that defines the life-time
    	   of it. A control process of a unit is one that is invoked by the
    	   manager to induce state changes of it. For example, all processes
    	   started due to the ExecStartPre=, ExecStop= or ExecReload= settings
    	   of service units are control processes. Note that there is only one
    	   control process per unit at a time, as only one state change is
    	   executed at a time. For services of type Type=forking, the initial
    	   process started by the manager for ExecStart= is a control process,
    	   while the process ultimately forked off by that one is then
    	   considered the main process of the unit (if it can be determined).
    	   This is different for service units of other types, where the
    	   process forked off by the manager for ExecStart= is always the main
    	   process itself. A service unit consists of zero or one main
    	   process, zero or one control process plus any number of additional
    	   processes. Not all unit types manage processes of these types
    	   however. For example, for mount units, control processes are
    	   defined (which are the invocations of /usr/bin/mount and
    	   /usr/bin/umount), but no main process is defined. If omitted,
    <standard input>:1337: warning [p 13, 4.2i]: can't break line
    	   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.
    
           --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 alternative 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".
    
           --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.
    
           --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 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 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. 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. 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 changes with
    	   --lines and --full, see above. In addition, journalctl --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 units required and wanted by the specified unit. This
    	   recursively lists units following the Requires=,
    	   RequiresOverridable=, Requisite=, RequisiteOverridable=, 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.
    
    	   If --runtime is specified, then this enables the unit only this
    	   boot.
    
    	   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 --runtime 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 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.
    
    	   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. To show installation targets,
    	   use --full.
    
    	   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 file is not    | 0		   |
    	   |		      | enabled, and has no |		   |
    	   |		      | provisions for	    |		   |
    	   |		      | enabling in the	    |		   |
    	   |		      | "[Install]"	    |		   |
    	   |		      | section.	    |		   |
    	   +------------------+---------------------+--------------+
    	   |"indirect"	      | 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    | 1		   |
    	   |		      | enabled.	    |		   |
    	   +------------------+---------------------+--------------+
    	   |"bad"	      | Unit file is	    | > 0	   |
    	   |		      | invalid or another  |		   |
    	   |		      | error occured. Note |		   |
    	   |		      | that is-enabled wil |		   |
    	   |		      | 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=" resp.	"Requires=" dependency to the specified TARGET
    	   for one or more units.
    
    	   This command honors --runtime in a similar way as enable.
    
           edit NAME...
    	   Edit a drop-in snippet or a whole replacement file if --full is
    	   specified, to extend or override the specified unit.
    
    	   This creates a drop-in file for a unit. 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.
    
       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 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 when
    	   the system is fully up and running, meaning not in startup,
    	   shutdown or maintenance mode. Failure is returned otherwise. In
    	   addition, the current state is printed in a short string to
    	   standard output, see table below. Use --quiet to suppress this
    	   output.
    
    	   Table 2. Manager Operational States
    	   +-------------+----------------------------+
    	   |Name	 | Description		      |
    	   +-------------+----------------------------+
    	   |initializing | Early bootup, before	      |
    	   |		 | basic.target is reached or |
    	   |		 | the maintenance state      |
    	   |		 | entered.		      |
    	   +-------------+----------------------------+
    	   |starting	 | Late bootup, before the    |
    	   |		 | job queue becomes idle for |
    	   |		 | the first time, or one of  |
    	   |		 | the rescue targets are     |
    	   |		 | reached.		      |
    	   +-------------+----------------------------+
    	   |running	 | The system is fully	      |
    	   |		 | operational.		      |
    	   +-------------+----------------------------+
    	   |degraded	 | The system is operational  |
    	   |		 | but one or more units      |
    	   |		 | failed.		      |
    	   +-------------+----------------------------+
    	   |maintenance	 | The rescue or emergency    |
    	   |		 | target is active.	      |
    	   +-------------+----------------------------+
    	   |stopping	 | The manager is shutting    |
    	   |		 | down.		      |
    	   +-------------+----------------------------+
    
           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.
    
           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, 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 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 [email protected]*.service
    
           will stop all [email protected] 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_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:
    	   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").
    
    EXAMPLES
           For examples how to use systemctl in comparsion with old service and
           chkconfig command please see: Managing System Services[2]
    
    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
    
    	2. Managing System Services
    	   https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/System_Administrators_Guide/sect-Managing_Services_with_systemd-Services.html
    
    
    
    systemd 219							  SYSTEMCTL(1)
    

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