List units that systemd currently has in memory. This includes units that are either referenced directly or through a dependency, units that are pinned by applications programmatically, or units that were active in the past and have failed. By default only units which are active, have pending jobs, or have failed are shown; this can be changed with option --all. If one or more PATTERNs are specified, only units matching one of them are shown. The units that are shown are additionally filtered by --type= and --state= if those options are specified.

Note that this command does not show unit templates, but only instances of unit templates. Units templates that aren't instantiated are not runnable, and will thus never show up in the output of this command. Specifically this means that foo@.service will never be shown in this list — unless instantiated, e.g. as foo@bar.service. Use list-unit-files (see below) for listing installed unit template files.

Produces output similar to

  UNIT                         LOAD   ACTIVE SUB     DESCRIPTION
  sys-module-fuse.device       loaded active plugged /sys/module/fuse
  -.mount                      loaded active mounted Root Mount
  boot-efi.mount               loaded active mounted /boot/efi
  systemd-journald.service     loaded active running Journal Service
  systemd-logind.service       loaded active running Login Service
● user@1000.service            loaded failed failed  User Manager for UID 1000
  …
  systemd-tmpfiles-clean.timer loaded active waiting Daily Cleanup of Temporary Directories

LOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

123 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.

The header and the last unit of a given type are underlined if the terminal supports that. A colored dot is shown next to services which were masked, not found, or otherwise failed.

The LOAD column shows the load state, one of loaded, not-found, bad-setting, error, masked. The ACTIVE columns shows the general unit state, one of active, reloading, inactive, failed, activating, deactivating. The SUB column shows the unit-type-specific detailed state of the unit, possible values vary by unit type. The list of possible LOAD, ACTIVE, and SUB states is not constant and new systemd releases may both add and remove values.

systemctl --state=help

command maybe be used to display the current set of possible values.

This is the default command.

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

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

5 sockets listed.

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

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

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

NEXT                         LEFT          LAST                         PASSED     UNIT                         ACTIVATES
n/a                          n/a           Thu 2017-02-23 13:40:29 EST  3 days ago ureadahead-stop.timer        ureadahead-stop.service
Sun 2017-02-26 18:55:42 EST  1min 14s left Thu 2017-02-23 13:54:44 EST  3 days ago systemd-tmpfiles-clean.timer systemd-tmpfiles-clean.service
Sun 2017-02-26 20:37:16 EST  1h 42min left Sun 2017-02-26 11:56:36 EST  6h ago     apt-daily.timer              apt-daily.service
Sun 2017-02-26 20:57:49 EST  2h 3min left  Sun 2017-02-26 11:56:36 EST  6h ago     snapd.refresh.timer          snapd.refresh.service
            

NEXT shows the next time the timer will run.

LEFT shows how long till the next time the timer runs.

LAST shows the last time the timer ran.

PASSED shows how long has passed since the timer last ran.

UNIT shows the name of the timer

ACTIVATES shows the name the service the timer activates when it runs.

Also see --all and --state=.

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.

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.

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

This function is intended to generate human-readable output. If you are looking for computer-parsable output, use show instead. By default, this function only shows 10 lines of output and ellipsizes lines to fit in the terminal window. This can be changed with --lines and --full, see above. In addition, journalctl --unit=NAME or journalctl --user-unit=NAME use a similar filter for messages and might be more convenient.

systemd implicitly loads units as necessary, so just running the status will attempt to load a file. The command is thus not useful for determining if something was already loaded or not. The units may possibly also be quickly unloaded after the operation is completed if there's no reason to keep it in memory thereafter.

$ systemctl status bluetooth
● bluetooth.service - Bluetooth service
   Loaded: loaded (/usr/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
   Active: active (running) since Wed 2017-01-04 13:54:04 EST; 1 weeks 0 days ago
     Docs: man:bluetoothd(8)
 Main PID: 930 (bluetoothd)
   Status: "Running"
    Tasks: 1
   Memory: 648.0K
      CPU: 435ms
   CGroup: /system.slice/bluetooth.service
           └─930 /usr/lib/bluetooth/bluetoothd

Jan 12 10:46:45 example.com bluetoothd[8900]: Not enough free handles to register service
Jan 12 10:46:45 example.com bluetoothd[8900]: Current Time Service could not be registered
Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output error (5)

Show properties of one or more units, jobs, or the manager itself. If no argument is specified, properties of the manager will be shown. If a unit name is specified, properties of the unit are shown, and if a job ID is specified, properties of the job are shown. By default, empty properties are suppressed. Use --all to show those too. To select specific properties to show, use --property=. This command is intended to be used whenever computer-parsable output is required. Use status if you are looking for formatted human-readable output.

Many properties shown by systemctl show map directly to configuration settings of the system and service manager and its unit files. Note that the properties shown by the command are generally more low-level, normalized versions of the original configuration settings and expose runtime state in addition to configuration. For example, properties shown for service units include the service's current main process identifier as "MainPID" (which is runtime state), and time settings are always exposed as properties ending in the "…USec" suffix even if a matching configuration options end in "…Sec", because microseconds is the normalized time unit used internally by the system and service manager.

For details about many of these properties, see the documentation of the D-Bus interface backing these properties, see org.freedesktop.systemd1(5).

Show backing files of one or more units. Prints the "fragment" and "drop-ins" (source files) of units. Each file is preceded by a comment which includes the file name. Note that this shows the contents of the backing files on disk, which may not match the system manager's understanding of these units if any unit files were updated on disk and the daemon-reload command wasn't issued since.

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.

Shows units required and wanted by the specified units. This recursively lists units following the Requires=, Requisite=, ConsistsOf=, Wants=, BindsTo= dependencies. If no units are specified, default.target is implied.

By default, only target units are recursively expanded. When --all is passed, all other units are recursively expanded as well.

Options --reverse, --after, --before may be used to change what types of dependencies are shown.

Note that this command only lists units currently loaded into memory by the service manager. In particular, this command is not suitable to get a comprehensive list at all reverse dependencies on a specific unit, as it won't list the dependencies declared by units currently not loaded.

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

Note that unit glob patterns expand to names of units currently in memory. Units which are not active and are not in a failed state usually are not in memory, and will not be matched by any pattern. In addition, in case of instantiated units, systemd is often unaware of the instance name until the instance has been started. Therefore, using glob patterns with start has limited usefulness. Also, secondary alias names of units are not considered.

Option --all may be used to also operate on inactive units which are referenced by other loaded units. Note that this is not the same as operating on "all" possible units, because as the previous paragraph describes, such a list is ill-defined. Nevertheless, systemctl start --all GLOB may be useful if all the units that should match the pattern are pulled in by some target which is known to be loaded.

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

This command will fail if the unit does not exist or if stopping of the unit is prohibited (see RefuseManualStop= in systemd.unit(5)). It will not fail if any of the commands configured to stop the unit (ExecStop=, etc.) fail, because the manager will still forcibly terminate the unit.

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.

Stop and then start one or more units specified on the command line. If the units are not running yet, they will be started.

Note that restarting a unit with this command does not necessarily flush out all of the unit's resources before it is started again. For example, the per-service file descriptor storage facility (see FileDescriptorStoreMax= in systemd.service(5)) will remain intact as long as the unit has a job pending, and is only cleared when the unit is fully stopped and no jobs are pending anymore. If it is intended that the file descriptor store is flushed out, too, during a restart operation an explicit systemctl stop command followed by systemctl start should be issued.

Stop and then start one or more units specified on the command line if the units are running. This does nothing if units are not running.

Reload one or more units if they support it. If not, stop and then start them instead. If the units are not running yet, they will be started.

Reload one or more units if they support it. If not, stop and then start them instead. This does nothing if the units are not running.

Start the unit specified on the command line and its dependencies and stop all others, unless they have IgnoreOnIsolate=yes (see systemd.unit(5)). If a unit name with no extension is given, an extension of ".target" will be assumed.

This command is dangerous, since it will immediately stop processes that are not enabled in the new target, possibly including the graphical environment or terminal you are currently using.

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

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.

Remove the configuration, state, cache, logs or runtime data of the specified units. Use --what= to select which kind of resource to remove. For service units this may be used to remove the directories configured with ConfigurationDirectory=, StateDirectory=, CacheDirectory=, LogsDirectory= and RuntimeDirectory=, see systemd.exec(5) for details. For timer units this may be used to clear out the persistent timestamp data if Persistent= is used and --what=state is selected, see systemd.timer(5). This command only applies to units that use either of these settings. If --what= is not specified, both the cache and runtime data are removed (as these two types of data are generally redundant and reproducible on the next invocation of the unit).

Freeze one or more units specified on the command line using cgroup freezer

Freezing the unit will cause all processes contained within the cgroup corresponding to the unit to be suspended. Being suspended means that unit's processes won't be scheduled to run on CPU until thawed. Note that this command is supported only on systems that use unified cgroup hierarchy. Unit is automatically thawed just before we execute a job against the unit, e.g. before the unit is stopped.

Thaw (unfreeze) one or more units specified on the command line.

This is the inverse operation to the freeze command and resumes the execution of processes in the unit's cgroup.

Set the specified unit properties at runtime where this is supported. This allows changing configuration parameter properties such as resource control settings at runtime. Not all properties may be changed at runtime, but many resource control settings (primarily those in systemd.resource-control(5)) may. The changes are applied immediately, and stored on disk for future boots, unless --runtime is passed, in which case the settings only apply until the next reboot. The syntax of the property assignment follows closely the syntax of assignments in unit files.

Example: systemctl set-property foobar.service CPUWeight=200

If the specified unit appears to be inactive, the changes will be only stored on disk as described previously hence they will be effective when the unit will be started.

Note that this command allows changing multiple properties at the same time, which is preferable over setting them individually.

Example: systemctl set-property foobar.service CPUWeight=200 MemoryMax=2G IPAccounting=yes

Like with unit file configuration settings, assigning an empty setting usually resets a property to its defaults.

Example: systemctl set-property avahi-daemon.service IPAddressDeny=

Bind-mounts a file or directory from the host into the specified unit's mount namespace. The first path argument is the source file or directory on the host, the second path argument is the destination file or directory in the unit's mount namespace. When the latter is omitted, the destination path in the unit's mount namespace is the same as the source path on the host. When combined with the --read-only switch, a ready-only bind mount is created. When combined with the --mkdir switch, the destination path is first created before the mount is applied.

Note that this option is currently only supported for units that run within a mount namespace (e.g.: with RootImage=, PrivateMounts=, etc.). This command supports bind-mounting directories, regular files, device nodes, AF_UNIX socket nodes, as well as FIFOs. The bind mount is ephemeral, and it is undone as soon as the current unit process exists. Note that the namespace mentioned here, where the bind mount will be added to, is the one where the main service process runs. Other processes (those exececuted by ExecReload=, ExecStartPre=, etc.) run in distinct namespaces.

Mounts an image from the host into the specified unit's mount namespace. The first path argument is the source image on the host, the second path argument is the destination directory in the unit's mount namespace (i.e. inside RootImage=/RootDirectory=). The following argument, if any, is interpreted as a colon-separated tuple of partition name and comma-separated list of mount options for that partition. The format is the same as the service MountImages= setting. When combined with the --read-only switch, a ready-only mount is created. When combined with the --mkdir switch, the destination path is first created before the mount is applied.

Note that this option is currently only supported for units that run within a mount namespace (i.e. with RootImage=, PrivateMounts=, etc.). Note that the namespace mentioned here where the image mount will be added to, is the one where the main service process runs. Note that the namespace mentioned here, where the bind mount will be added to, is the one where the main service process runs. Other processes (those exececuted by ExecReload=, ExecStartPre=, etc.) run in distinct namespaces.

Example:

systemctl mount-image foo.service /tmp/img.raw /var/lib/image root:ro,nosuid

systemctl mount-image --mkdir bar.service /tmp/img.raw /var/lib/baz/img

If the LEVEL argument is not given, print the current log level as reported by service SERVICE.

If the optional argument LEVEL is provided, then change the current log level of the service to LEVEL. The log level should be a typical syslog log level, i.e. a value in the range 0…7 or one of the strings emerg, alert, crit, err, warning, notice, info, debug; see syslog(3) for details.

The service must have the appropriate BusName=destination property and also implement the generic org.freedesktop.LogControl1(5) interface. (systemctl will use the generic D-Bus protocol to access the org.freedesktop.LogControl1.LogLevel interface for the D-Bus name destination.)

If the TARGET argument is not given, print the current log target as reported by service SERVICE.

If the optional argument TARGET is provided, then change the current log target of the service to TARGET. The log target should be one of the strings console (for log output to the service's standard error stream), kmsg (for log output to the kernel log buffer), journal (for log output to systemd-journald.service(8) using the native journal protocol), syslog (for log output to the classic syslog socket /dev/log), null (for no log output whatsoever) or auto (for an automatically determined choice, typically equivalent to console if the service is invoked interactively, and journal or syslog otherwise).

For most services, only a small subset of log targets make sense. In particular, most "normal" services should only implement console, journal, and null. Anything else is only appropriate for low-level services that are active in very early boot before proper logging is established.

The service must have the appropriate BusName=destination property and also implement the generic org.freedesktop.LogControl1(5) interface. (systemctl will use the generic D-Bus protocol to access the org.freedesktop.LogControl1.LogLevel interface for the D-Bus name destination.)

Reset the "failed" state of the specified units, or if no unit name is passed, reset the state of all units. When a unit fails in some way (i.e. process exiting with non-zero error code, terminating abnormally or timing out), it will automatically enter the "failed" state and its exit code and status is recorded for introspection by the administrator until the service is stopped/re-started or reset with this command.

In addition to resetting the "failed" state of a unit it also resets various other per-unit properties: the start rate limit counter of all unit types is reset to zero, as is the restart counter of service units. Thus, if a unit's start limit (as configured with StartLimitIntervalSec=/StartLimitBurst=) is hit and the unit refuses to be started again, use this command to make it startable again.

List unit files installed on the system, in combination with their enablement state (as reported by is-enabled). If one or more PATTERNs are specified, only unit files whose name matches one of them are shown (patterns matching unit file system paths are not supported).

Unlike list-units this command will list template units in addition to explicitly instantiated units.

Enable one or more units or unit instances. This will create a set of symlinks, as encoded in the [Install] sections of the indicated unit files. After the symlinks have been created, the system manager configuration is reloaded (in a way equivalent to daemon-reload), in order to ensure the changes are taken into account immediately. Note that this does not have the effect of also starting any of the units being enabled. If this is desired, combine this command with the --now switch, or invoke start with appropriate arguments later. Note that in case of unit instance enablement (i.e. enablement of units of the form foo@bar.service), symlinks named the same as instances are created in the unit configuration directory, however they point to the single template unit file they are instantiated from.

This command expects either valid unit names (in which case various unit file directories are automatically searched for unit files with appropriate names), or absolute paths to unit files (in which case these files are read directly). If a specified unit file is located outside of the usual unit file directories, an additional symlink is created, linking it into the unit configuration path, thus ensuring it is found when requested by commands such as start. The file system where the linked unit files are located must be accessible when systemd is started (e.g. anything underneath /home/ or /var/ is not allowed, unless those directories are located on the root file system).

This command will print the file system operations executed. This output may be suppressed by passing --quiet.

Note that this operation creates only the symlinks suggested in the [Install] section of the unit files. While this command is the recommended way to manipulate the unit configuration directory, the administrator is free to make additional changes manually by placing or removing symlinks below this directory. This is particularly useful to create configurations that deviate from the suggested default installation. In this case, the administrator must make sure to invoke daemon-reload manually as necessary, in order to ensure the changes are taken into account.

Enabling units should not be confused with starting (activating) units, as done by the start command. Enabling and starting units is orthogonal: units may be enabled without being started and started without being enabled. Enabling simply hooks the unit into various suggested places (for example, so that the unit is automatically started on boot or when a particular kind of hardware is plugged in). Starting actually spawns the daemon process (in case of service units), or binds the socket (in case of socket units), and so on.

Depending on whether --system, --user, --runtime, or --global is specified, this enables the unit for the system, for the calling user only, for only this boot of the system, or for all future logins of all users. Note that in the last case, no systemd daemon configuration is reloaded.

Using enable on masked units is not supported and results in an error.

Disables one or more units. This removes all symlinks to the unit files backing the specified units from the unit configuration directory, and hence undoes any changes made by enable or link. Note that this removes all symlinks to matching unit files, including manually created symlinks, and not just those actually created by enable or link. Note that while disable undoes the effect of enable, the two commands are otherwise not symmetric, as disable may remove more symlinks than a prior enable invocation of the same unit created.

This command expects valid unit names only, it does not accept paths to unit files.

In addition to the units specified as arguments, all units are disabled that are listed in the Also= setting contained in the [Install] section of any of the unit files being operated on.

This command implicitly reloads the system manager configuration after completing the operation. Note that this command does not implicitly stop the units that are being disabled. If this is desired, either combine this command with the --now switch, or invoke the stop command with appropriate arguments later.

This command will print information about the file system operations (symlink removals) executed. This output may be suppressed by passing --quiet.

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

Reenable one or more units, as specified on the command line. This is a combination of disable and enable and is useful to reset the symlinks a unit file is enabled with to the defaults configured in its [Install] section. This command expects a unit name only, it does not accept paths to unit files.

Reset the enable/disable status one or more unit files, as specified on the command line, to the defaults configured in the preset policy files. This has the same effect as disable or enable, depending how the unit is listed in the preset files.

Use --preset-mode= to control whether units shall be enabled and disabled, or only enabled, or only disabled.

If the unit carries no install information, it will be silently ignored by this command. UNIT must be the real unit name, any alias names are ignored silently.

For more information on the preset policy format, see systemd.preset(5).

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.

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.

Mask one or more units, as specified on the command line. This will link these unit files to /dev/null, making it impossible to start them. This is a stronger version of disable, since it prohibits all kinds of activation of the unit, including enablement and manual activation. Use this option with care. This honors the --runtime option to only mask temporarily until the next reboot of the system. The --now option may be used to ensure that the units are also stopped. This command expects valid unit names only, it does not accept unit file paths.

Unmask one or more unit files, as specified on the command line. This will undo the effect of mask. This command expects valid unit names only, it does not accept unit file paths.

Link a unit file that is not in the unit file search paths into the unit file search path. This command expects an absolute path to a unit file. The effect of this may be undone with disable. The effect of this command is that a unit file is made available for commands such as start, even though it is not installed directly in the unit search path. The file system where the linked unit files are located must be accessible when systemd is started (e.g. anything underneath /home/ or /var/ is not allowed, unless those directories are located on the root file system).

Revert one or more unit files to their vendor versions. This command removes drop-in configuration files that modify the specified units, as well as any user-configured unit file that overrides a matching vendor supplied unit file. Specifically, for a unit "foo.service" the matching directories "foo.service.d/" with all their contained files are removed, both below the persistent and runtime configuration directories (i.e. below /etc/systemd/system and /run/systemd/system); if the unit file has a vendor-supplied version (i.e. a unit file located below /usr/) any matching persistent or runtime unit file that overrides it is removed, too. Note that if a unit file has no vendor-supplied version (i.e. is only defined below /etc/systemd/system or /run/systemd/system, but not in a unit file stored below /usr/), then it is not removed. Also, if a unit is masked, it is unmasked.

Effectively, this command may be used to undo all changes made with systemctl edit, systemctl set-property and systemctl mask and puts the original unit file with its settings back in effect.

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

Depending on whether --system (the default), --user, or --global is specified, this command creates a drop-in file for each unit either for the system, for the calling user, or for all futures logins of all users. Then, the editor (see the "Environment" section below) is invoked on temporary files which will be written to the real location if the editor exits successfully.

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

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

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

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

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

Note that this command cannot be used to remotely edit units and that you cannot temporarily edit units which are in /etc/, since they take precedence over /run/.

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

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

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.

List jobs that are in progress. If one or more PATTERNs are specified, only jobs for units matching one of them are shown.

When combined with --after or --before the list is augmented with information on which other job each job is waiting for, and which other jobs are waiting for it, see above.

Cancel one or more jobs specified on the command line by their numeric job IDs. If no job ID is specified, cancel all pending jobs.

Dump the systemd manager environment block. This is the environment block that is passed to all processes the manager spawns. The environment block will be dumped in straight-forward form suitable for sourcing into most shells. If no special characters or whitespace is present in the variable values, no escaping is performed, and the assignments have the form "VARIABLE=value". If whitespace or characters which have special meaning to the shell are present, dollar-single-quote escaping is used, and assignments have the form "VARIABLE=$'value'". This syntax is known to be supported by bash(1), zsh(1), ksh(1), and busybox(1)'s ash(1), but not dash(1) or fish(1).

Set one or more systemd manager environment variables, as specified on the command line. This command will fail if variable names and values do not conform to the rules listed above.

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 all, one or more environment variables set on the client into the systemd manager environment block. If a list of environment variable names is passed, client-side values are then imported into the manager's environment block. If any names are not valid environment variable names or have invalid values according to the rules described above, an error is raised. If no arguments are passed, the entire environment block inherited by the systemctl process is imported. In this mode, any inherited invalid environment variables are quietly ignored.

Importing of the full inherited environment block (calling this command without any arguments) is deprecated. A shell will set dozens of variables which only make sense locally and are only meant for processes which are descendants of the shell. Such variables in the global environment block are confusing to other processes.

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.

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.

If no argument is given, print the current log level of the manager. If an optional argument LEVEL is provided, then the command changes the current log level of the manager to LEVEL (accepts the same values as --log-level= described in systemd(1)).

If no argument is given, print the current log target of the manager. If an optional argument TARGET is provided, then the command changes the current log target of the manager to TARGET (accepts the same values as --log-target=, described in systemd(1)).

If no argument is given, print the current state of service runtime watchdogs of the manager. If an optional boolean argument is provided, then globally enables or disables the service runtime watchdogs (WatchdogSec=) and emergency actions (e.g. OnFailure= or StartLimitAction=); see systemd.service(5). The hardware watchdog is not affected by this setting.

Checks whether the system is operational. This returns success (exit code 0) when the system is fully up and running, specifically not in startup, shutdown or maintenance mode, and with no failed services. Failure is returned otherwise (exit code non-zero). In addition, the current state is printed in a short string to standard output, see the table below. Use --quiet to suppress this output.

Use --wait to wait until the boot process is completed before printing the current state and returning the appropriate error status. If --wait is in use, states initializing or starting will not be reported, instead the command will block until a later state (such as running or degraded) is reached.

Enter default mode. This is equivalent to systemctl isolate default.target. This operation is blocking by default, use --no-block to request asynchronous behavior.

Enter rescue mode. This is equivalent to systemctl isolate rescue.target. This operation is blocking by default, use --no-block to request asynchronous behavior.

Enter emergency mode. This is equivalent to systemctl isolate emergency.target. This operation is blocking by default, use --no-block to request asynchronous behavior.

Shut down and halt the system. This is mostly equivalent to systemctl start halt.target --job-mode=replace-irreversibly --no-block, but also prints a wall message to all users. This command is asynchronous; it will return after the halt operation is enqueued, without waiting for it to complete. Note that this operation will simply halt the OS kernel after shutting down, leaving the hardware powered on. Use systemctl poweroff for powering off the system (see below).

If combined with --force, shutdown of all running services is skipped, however all processes are killed and all file systems are unmounted or mounted read-only, immediately followed by the system halt. If --force is specified twice, the operation is immediately executed without terminating any processes or unmounting any file systems. This may result in data loss. Note that when --force is specified twice the halt operation is executed by systemctl itself, and the system manager is not contacted. This means the command should succeed even when the system manager has crashed.

Shut down and power-off the system. This is mostly equivalent to systemctl start poweroff.target --job-mode=replace-irreversibly --no-block, but also prints a wall message to all users. This command is asynchronous; it will return after the power-off operation is enqueued, without waiting for it to complete.

If combined with --force, shutdown of all running services is skipped, however all processes are killed and all file systems are unmounted or mounted read-only, immediately followed by the powering off. If --force is specified twice, the operation is immediately executed without terminating any processes or unmounting any file systems. This may result in data loss. Note that when --force is specified twice the power-off operation is executed by systemctl itself, and the system manager is not contacted. This means the command should succeed even when the system manager has crashed.

Shut down and reboot the system. This is mostly equivalent to systemctl start reboot.target --job-mode=replace-irreversibly --no-block, but also prints a wall message to all users. This command is asynchronous; it will return after the reboot operation is enqueued, without waiting for it to complete.

If combined with --force, shutdown of all running services is skipped, however all processes are killed and all file systems are unmounted or mounted read-only, immediately followed by the reboot. If --force is specified twice, the operation is immediately executed without terminating any processes or unmounting any file systems. This may result in data loss. Note that when --force is specified twice the reboot operation is executed by systemctl itself, and the system manager is not contacted. This means the command should succeed even when the system manager has crashed.

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

Shut down and reboot the system via kexec. This is equivalent to systemctl start kexec.target --job-mode=replace-irreversibly --no-block. This command is asynchronous; it will return after the reboot operation is enqueued, without waiting for it to complete.

If combined with --force, shutdown of all running services is skipped, however all processes are killed and all file systems are unmounted or mounted read-only, immediately followed by the reboot.

Ask the service manager to quit. This is only supported for user service managers (i.e. in conjunction with the --user option) or in containers and is equivalent to poweroff otherwise. This command is asynchronous; it will return after the exit operation is enqueued, without waiting for it to complete.

The service manager will exit with the specified exit code, if EXIT_CODE is passed.

Switches to a different root directory and executes a new system manager process below it. This is intended for usage in initial RAM disks ("initrd"), and will transition from the initrd's system manager process (a.k.a. "init" process) to the main system manager process which is loaded from the actual host volume. This call takes two arguments: the directory that is to become the new root directory, and the path to the new system manager binary below it to execute as PID 1. If the latter is omitted or the empty string, a systemd binary will automatically be searched for and used as init. If the system manager path is omitted, equal to the empty string or identical to the path to the systemd binary, the state of the initrd's system manager process is passed to the main system manager, which allows later introspection of the state of the services involved in the initrd boot phase.

Suspend the system. This will trigger activation of the special target unit suspend.target. This command is asynchronous, and will return after the suspend operation is successfully enqueued. It will not wait for the suspend/resume cycle to complete.

Hibernate the system. This will trigger activation of the special target unit hibernate.target. This command is asynchronous, and will return after the hibernation operation is successfully enqueued. It will not wait for the hibernate/thaw cycle to complete.

Hibernate and suspend the system. This will trigger activation of the special target unit hybrid-sleep.target. This command is asynchronous, and will return after the hybrid sleep operation is successfully enqueued. It will not wait for the sleep/wake-up cycle to complete.

Suspend the system and hibernate it after the delay specified in systemd-sleep.conf. This will trigger activation of the special target unit suspend-then-hibernate.target. This command is asynchronous, and will return after the hybrid sleep operation is successfully enqueued. It will not wait for the sleep/wake-up or hibernate/thaw cycle to complete.