systemd.unit(5) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | STRING ESCAPING FOR INCLUSION IN UNIT NAMES | AUTOMATIC DEPENDENCIES | UNIT FILE LOAD PATH | UNIT GARBAGE COLLECTION | [UNIT] SECTION OPTIONS | MAPPING OF UNIT PROPERTIES TO THEIR INVERSES | [INSTALL] SECTION OPTIONS | SPECIFIERS | EXAMPLES | SEE ALSO | NOTES | COLOPHON

SYSTEMD.UNIT(5)                 systemd.unit                 SYSTEMD.UNIT(5)

NAME         top

       systemd.unit - Unit configuration

SYNOPSIS         top

       service.service, socket.socket, device.device, mount.mount,
       automount.automount, swap.swap, target.target, path.path,
       timer.timer, slice.slice, scope.scope

   System Unit Search Path
       /etc/systemd/system.control/*
       /run/systemd/system.control/*
       /run/systemd/transient/*
       /run/systemd/generator.early/*
       /etc/systemd/system/*
       /etc/systemd/systemd.attached/*
       /run/systemd/system/*
       /run/systemd/systemd.attached/*
       /run/systemd/generator/*
       ...
       /usr/lib/systemd/system/*
       /run/systemd/generator.late/*

   User Unit Search Path
       ~/.config/systemd/user.control/*
       $XDG_RUNTIME_DIR/systemd/user.control/*
       $XDG_RUNTIME_DIR/systemd/transient/*
       $XDG_RUNTIME_DIR/systemd/generator.early/*
       $XDG_CONFIG_HOME/systemd/user/*
       $XDG_CONFIG_DIRS/systemd/user/*
       /etc/systemd/user/*
       $XDG_RUNTIME_DIR/systemd/user/*
       /run/systemd/user/*
       $XDG_RUNTIME_DIR/systemd/generator/*
       $XDG_DATA_HOME/systemd/user/*
       $XDG_DATA_DIRS/systemd/user/*
       ...
       /usr/lib/systemd/user/*
       $XDG_RUNTIME_DIR/systemd/generator.late/*

DESCRIPTION         top

       A unit file is a plain text ini-style file that encodes information
       about a service, a socket, a device, a mount point, an automount
       point, a swap file or partition, a start-up target, a watched file
       system path, a timer controlled and supervised by systemd(1), a
       resource management slice or a group of externally created processes.
       See systemd.syntax(7) for a general description of the syntax.

       This man page lists the common configuration options of all the unit
       types. These options need to be configured in the [Unit] or [Install]
       sections of the unit files.

       In addition to the generic [Unit] and [Install] sections described
       here, each unit may have a type-specific section, e.g. [Service] for
       a service unit. See the respective man pages for more information:
       systemd.service(5), systemd.socket(5), systemd.device(5),
       systemd.mount(5), systemd.automount(5), systemd.swap(5),
       systemd.target(5), systemd.path(5), systemd.timer(5),
       systemd.slice(5), systemd.scope(5).

       Unit files are loaded from a set of paths determined during
       compilation, described in the next section.

       Valid unit names consist of a "name prefix" and a dot and a suffix
       specifying the unit type. The "unit prefix" must consist of one or
       more valid characters (ASCII letters, digits, ":", "-", "_", ".", and
       "\"). The total length of the unit name including the suffix must not
       exceed 256 characters. The type suffix must be one of ".service",
       ".socket", ".device", ".mount", ".automount", ".swap", ".target",
       ".path", ".timer", ".slice", or ".scope".

       Units names can be parameterized by a single argument called the
       "instance name". The unit is then constructed based on a "template
       file" which serves as the definition of multiple services or other
       units. A template unit must have a single "@" at the end of the name
       (right before the type suffix). The name of the full unit is formed
       by inserting the instance name between "@" and the unit type suffix.
       In the unit file itself, the instance parameter may be referred to
       using "%i" and other specifiers, see below.

       Unit files may contain additional options on top of those listed
       here. If systemd encounters an unknown option, it will write a
       warning log message but continue loading the unit. If an option or
       section name is prefixed with X-, it is ignored completely by
       systemd. Options within an ignored section do not need the prefix.
       Applications may use this to include additional information in the
       unit files.

       Units can be aliased (have an alternative name), by creating a
       symlink from the new name to the existing name in one of the unit
       search paths. For example, systemd-networkd.service has the alias
       dbus-org.freedesktop.network1.service, created during installation as
       a symlink, so when systemd is asked through D-Bus to load
       dbus-org.freedesktop.network1.service, it'll load
       systemd-networkd.service. As another example, default.target — the
       default system target started at boot — is commonly symlinked
       (aliased) to either multi-user.target or graphical.target to select
       what is started by default. Alias names may be used in commands like
       disable, start, stop, status, and similar, and in all unit dependency
       directives, including Wants=, Requires=, Before=, After=. Aliases
       cannot be used with the preset command.

       Aliases obey the following restrictions: a unit of a certain type
       (".service", ".socket", ...) can only be aliased by a name with the
       same type suffix. A plain unit (not a template or an instance), may
       only be aliased by a plain name. A template instance may only be
       aliased by another template instance, and the instance part must be
       identical. A template may be aliased by another template (in which
       case the alias applies to all instances of the template). As a
       special case, a template instance (e.g.  "alias@inst.service") may be
       a symlink to different template (e.g.  "template@inst.service"). In
       that case, just this specific instance is aliased, while other
       instances of the template (e.g.  "alias@foo.service",
       "alias@bar.service") are not aliased. Those rule preserve the
       requirement that the instance (if any) is always uniquely defined for
       a given unit and all its aliases.

       Unit files may specify aliases through the Alias= directive in the
       [Install] section. When the unit is enabled, symlinks will be created
       for those names, and removed when the unit is disabled. For example,
       reboot.target specifies Alias=ctrl-alt-del.target, so when enabled,
       the symlink /etc/systemd/systemd/ctrl-alt-del.service pointing to the
       reboot.target file will be created, and when Ctrl+Alt+Del is invoked,
       systemd will look for the ctrl-alt-del.service and execute
       reboot.service.  systemd does not look at the [Install] section at
       all during normal operation, so any directives in that section only
       have an effect through the symlinks created during enablement.

       Along with a unit file foo.service, the directory foo.service.wants/
       may exist. All unit files symlinked from such a directory are
       implicitly added as dependencies of type Wants= to the unit. Similar
       functionality exists for Requires= type dependencies as well, the
       directory suffix is .requires/ in this case. This functionality is
       useful to hook units into the start-up of other units, without having
       to modify their unit files. For details about the semantics of
       Wants=, see below. The preferred way to create symlinks in the
       .wants/ or .requires/ directory of a unit file is by embedding the
       dependency in [Install] section of the target unit, and creating the
       symlink in the file system with the enable or preset commands of
       systemctl(1).

       Along with a unit file foo.service, a "drop-in" directory
       foo.service.d/ may exist. All files with the suffix ".conf" from this
       directory will be parsed after the unit file itself is parsed. This
       is useful to alter or add configuration settings for a unit, without
       having to modify unit files. Drop-in files must contain appropriate
       section headers. For instantiated units, this logic will first look
       for the instance ".d/" subdirectory (e.g.  "foo@bar.service.d/") and
       read its ".conf" files, followed by the template ".d/" subdirectory
       (e.g.  "foo@.service.d/") and the ".conf" files there. Moreover for
       units names containing dashes ("-"), the set of directories generated
       by truncating the unit name after all dashes is searched too.
       Specifically, for a unit name foo-bar-baz.service not only the
       regular drop-in directory foo-bar-baz.service.d/ is searched but also
       both foo-bar-.service.d/ and foo-.service.d/. This is useful for
       defining common drop-ins for a set of related units, whose names
       begin with a common prefix. This scheme is particularly useful for
       mount, automount and slice units, whose systematic naming structure
       is built around dashes as component separators. Note that equally
       named drop-in files further down the prefix hierarchy override those
       further up, i.e.  foo-bar-.service.d/10-override.conf overrides
       foo-.service.d/10-override.conf.

       In cases of unit aliases (described above), dropins for the aliased
       name and all aliases are loaded. In the example of default.target
       aliasing graphical.target, default.target.d/, default.target.wants/,
       default.target.requires/, graphical.target.d/,
       graphical.target.wants/, graphical.target.requires/ would all be
       read. For templates, dropins for the template, any template aliases,
       the template instance, and all alias instances are read. When just a
       specific template instance is aliased, then the dropins for the
       target template, the target template instance, and the alias template
       instance are read.

       In addition to /etc/systemd/system, the drop-in ".d/" directories for
       system services can be placed in /usr/lib/systemd/system or
       /run/systemd/system directories. Drop-in files in /etc/ take
       precedence over those in /run/ which in turn take precedence over
       those in /usr/lib/. Drop-in files under any of these directories take
       precedence over unit files wherever located. Multiple drop-in files
       with different names are applied in lexicographic order, regardless
       of which of the directories they reside in.

       Units also support a top-level drop-in with type.d/, where type may
       be e.g.  "service" or "socket", that allows altering or adding to the
       settings of all corresponding unit files on the system. The
       formatting and precedence of applying drop-in configurations follow
       what is defined above. Configurations in type.d/ have the lowest
       precedence compared to settings in the name specific override
       directories. So the contents of foo-.service.d/10-override.conf would
       override service.d/10-override.conf.

       Note that while systemd offers a flexible dependency system between
       units it is recommended to use this functionality only sparingly and
       instead rely on techniques such as bus-based or socket-based
       activation which make dependencies implicit, resulting in a both
       simpler and more flexible system.

       As mentioned above, a unit may be instantiated from a template file.
       This allows creation of multiple units from a single configuration
       file. If systemd looks for a unit configuration file, it will first
       search for the literal unit name in the file system. If that yields
       no success and the unit name contains an "@" character, systemd will
       look for a unit template that shares the same name but with the
       instance string (i.e. the part between the "@" character and the
       suffix) removed. Example: if a service getty@tty3.service is
       requested and no file by that name is found, systemd will look for
       getty@.service and instantiate a service from that configuration file
       if it is found.

       To refer to the instance string from within the configuration file
       you may use the special "%i" specifier in many of the configuration
       options. See below for details.

       If a unit file is empty (i.e. has the file size 0) or is symlinked to
       /dev/null, its configuration will not be loaded and it appears with a
       load state of "masked", and cannot be activated. Use this as an
       effective way to fully disable a unit, making it impossible to start
       it even manually.

       The unit file format is covered by the Interface Portability and
       Stability Promise[1].

STRING ESCAPING FOR INCLUSION IN UNIT NAMES         top

       Sometimes it is useful to convert arbitrary strings into unit names.
       To facilitate this, a method of string escaping is used, in order to
       map strings containing arbitrary byte values (except NUL) into valid
       unit names and their restricted character set. A common special case
       are unit names that reflect paths to objects in the file system
       hierarchy. Example: a device unit dev-sda.device refers to a device
       with the device node /dev/sda in the file system.

       The escaping algorithm operates as follows: given a string, any "/"
       character is replaced by "-", and all other characters which are not
       ASCII alphanumerics or "_" are replaced by C-style "\x2d" escapes. In
       addition, "."  is replaced with such a C-style escape when it would
       appear as the first character in the escaped string.

       When the input qualifies as absolute file system path, this algorithm
       is extended slightly: the path to the root directory "/" is encoded
       as single dash "-". In addition, any leading, trailing or duplicate
       "/" characters are removed from the string before transformation.
       Example: /foo//bar/baz/ becomes "foo-bar-baz".

       This escaping is fully reversible, as long as it is known whether the
       escaped string was a path (the unescaping results are different for
       paths and non-path strings). The systemd-escape(1) command may be
       used to apply and reverse escaping on arbitrary strings. Use
       systemd-escape --path to escape path strings, and systemd-escape
       without --path otherwise.

AUTOMATIC DEPENDENCIES         top

   Implicit Dependencies
       A number of unit dependencies are implicitly established, depending
       on unit type and unit configuration. These implicit dependencies can
       make unit configuration file cleaner. For the implicit dependencies
       in each unit type, please refer to section "Implicit Dependencies" in
       respective man pages.

       For example, service units with Type=dbus automatically acquire
       dependencies of type Requires= and After= on dbus.socket. See
       systemd.service(5) for details.

   Default Dependencies
       Default dependencies are similar to implicit dependencies, but can be
       turned on and off by setting DefaultDependencies= to yes (the
       default) and no, while implicit dependencies are always in effect.
       See section "Default Dependencies" in respective man pages for the
       effect of enabling DefaultDependencies= in each unit types.

       For example, target units will complement all configured dependencies
       of type Wants= or Requires= with dependencies of type After= unless
       DefaultDependencies=no is set in the specified units. See
       systemd.target(5) for details. Note that this behavior can be turned
       off by setting DefaultDependencies=no.

UNIT FILE LOAD PATH         top

       Unit files are loaded from a set of paths determined during
       compilation, described in the two tables below. Unit files found in
       directories listed earlier override files with the same name in
       directories lower in the list.

       When the variable $SYSTEMD_UNIT_PATH is set, the contents of this
       variable overrides the unit load path. If $SYSTEMD_UNIT_PATH ends
       with an empty component (":"), the usual unit load path will be
       appended to the contents of the variable.

       Table 1.  Load path when running in system mode (--system).
       ┌──────────────────────────────┬───────────────────────────┐
       │Path                          Description               │
       ├──────────────────────────────┼───────────────────────────┤
       │/etc/systemd/system.control   │ Persistent and transient  │
       ├──────────────────────────────┤ configuration created     │
       │/run/systemd/system.control   │ using the dbus API        │
       ├──────────────────────────────┼───────────────────────────┤
       │/run/systemd/transient        │ Dynamic configuration for │
       │                              │ transient units           │
       ├──────────────────────────────┼───────────────────────────┤
       │/run/systemd/generator.early  │ Generated units with high │
       │                              │ priority (see early-dir   │
       │                              │ in systemd.generator(7))  │
       ├──────────────────────────────┼───────────────────────────┤
       │/etc/systemd/system           │ System units created by   │
       │                              │ the administrator         │
       ├──────────────────────────────┼───────────────────────────┤
       │/run/systemd/system           │ Runtime units             │
       ├──────────────────────────────┼───────────────────────────┤
       │/run/systemd/generator        │ Generated units with      │
       │                              │ medium priority (see      │
       │                              │ normal-dir in             │
       │                              │ systemd.generator(7))     │
       ├──────────────────────────────┼───────────────────────────┤
       │/usr/local/lib/systemd/system │ System units installed by │
       │                              │ the administrator         │
       ├──────────────────────────────┼───────────────────────────┤
       │/usr/lib/systemd/system       │ System units installed by │
       │                              │ the distribution package  │
       │                              │ manager                   │
       ├──────────────────────────────┼───────────────────────────┤
       │/run/systemd/generator.late   │ Generated units with low  │
       │                              │ priority (see late-dir in │
       │                              │ systemd.generator(7))     │
       └──────────────────────────────┴───────────────────────────┘

       Table 2.  Load path when running in user mode (--user).
       ┌────────────────────────────────────────┬───────────────────────────┐
       │Path                                    Description               │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$XDG_CONFIG_HOME/systemd/user.control   │ Persistent and transient  │
       │or                                      │ configuration created     │
       │~/.config/systemd/user.control          │ using the dbus API        │
       ├────────────────────────────────────────┤ ($XDG_CONFIG_HOME is used │
       │$XDG_RUNTIME_DIR/systemd/user.control   │ if set, ~/.config         │
       │                                        │ otherwise)                │
       ├────────────────────────────────────────┼───────────────────────────┤
       │/run/systemd/transient                  │ Dynamic configuration for │
       │                                        │ transient units           │
       ├────────────────────────────────────────┼───────────────────────────┤
       │/run/systemd/generator.early            │ Generated units with high │
       │                                        │ priority (see early-dir   │
       │                                        │ in systemd.generator(7))  │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$XDG_CONFIG_HOME/systemd/user or        │ User configuration        │
       │$HOME/.config/systemd/user              │ ($XDG_CONFIG_HOME is used │
       │                                        │ if set, ~/.config         │
       │                                        │ otherwise)                │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$XDG_CONFIG_DIRS/systemd/user or        │ Additional configuration  │
       │/etc/xdg/systemd/user                   │ directories as specified  │
       │                                        │ by the XDG base directory │
       │                                        │ specification             │
       │                                        │ ($XDG_CONFIG_DIRS is used │
       │                                        │ if set, /etc/xdg          │
       │                                        │ otherwise)                │
       ├────────────────────────────────────────┼───────────────────────────┤
       │/etc/systemd/user                       │ User units created by the │
       │                                        │ administrator             │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$XDG_RUNTIME_DIR/systemd/user           │ Runtime units (only used  │
       │                                        │ when $XDG_RUNTIME_DIR is  │
       │                                        │ set)                      │
       ├────────────────────────────────────────┼───────────────────────────┤
       │/run/systemd/user                       │ Runtime units             │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$XDG_RUNTIME_DIR/systemd/generator      │ Generated units with      │
       │                                        │ medium priority (see      │
       │                                        │ normal-dir in             │
       │                                        │ systemd.generator(7))     │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$XDG_DATA_HOME/systemd/user or          │ Units of packages that    │
       │$HOME/.local/share/systemd/user         │ have been installed in    │
       │                                        │ the home directory        │
       │                                        │ ($XDG_DATA_HOME is used   │
       │                                        │ if set, ~/.local/share    │
       │                                        │ otherwise)                │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$XDG_DATA_DIRS/systemd/user or          │ Additional data           │
       │/usr/local/share/systemd/user and       │ directories as specified  │
       │/usr/share/systemd/user                 │ by the XDG base directory │
       │                                        │ specification             │
       │                                        │ ($XDG_DATA_DIRS is used   │
       │                                        │ if set, /usr/local/share  │
       │                                        │ and /usr/share otherwise) │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$dir/systemd/user for each $dir in      │ Additional locations for  │
       │$XDG_DATA_DIRS                          │ installed user units, one │
       │                                        │ for each entry in         │
       │                                        │ $XDG_DATA_DIRS            │
       ├────────────────────────────────────────┼───────────────────────────┤
       │/usr/local/lib/systemd/user             │ User units installed by   │
       │                                        │ the administrator         │
       ├────────────────────────────────────────┼───────────────────────────┤
       │/usr/lib/systemd/user                   │ User units installed by   │
       │                                        │ the distribution package  │
       │                                        │ manager                   │
       ├────────────────────────────────────────┼───────────────────────────┤
       │$XDG_RUNTIME_DIR/systemd/generator.late │ Generated units with low  │
       │                                        │ priority (see late-dir in │
       │                                        │ systemd.generator(7))     │
       └────────────────────────────────────────┴───────────────────────────┘

       The set of load paths for the user manager instance may be augmented
       or changed using various environment variables. And environment
       variables may in turn be set using environment generators, see
       systemd.environment-generator(7). In particular, $XDG_DATA_HOME and
       $XDG_DATA_DIRS may be easily set using
       systemd-environment-d-generator(8). Thus, directories listed here are
       just the defaults. To see the actual list that would be used based on
       compilation options and current environment use

           systemd-analyze --user unit-paths

       Moreover, additional units might be loaded into systemd from
       directories not on the unit load path by creating a symlink pointing
       to a unit file in the directories. You can use systemctl link for
       this operation. See systemctl(1) for its usage and precaution.

UNIT GARBAGE COLLECTION         top

       The system and service manager loads a unit's configuration
       automatically when a unit is referenced for the first time. It will
       automatically unload the unit configuration and state again when the
       unit is not needed anymore ("garbage collection"). A unit may be
       referenced through a number of different mechanisms:

        1. Another loaded unit references it with a dependency such as
           After=, Wants=, ...

        2. The unit is currently starting, running, reloading or stopping.

        3. The unit is currently in the failed state. (But see below.)

        4. A job for the unit is pending.

        5. The unit is pinned by an active IPC client program.

        6. The unit is a special "perpetual" unit that is always active and
           loaded. Examples for perpetual units are the root mount unit
           -.mount or the scope unit init.scope that the service manager
           itself lives in.

        7. The unit has running processes associated with it.

       The garbage collection logic may be altered with the CollectMode=
       option, which allows configuration whether automatic unloading of
       units that are in failed state is permissible, see below.

       Note that when a unit's configuration and state is unloaded, all
       execution results, such as exit codes, exit signals, resource
       consumption and other statistics are lost, except for what is stored
       in the log subsystem.

       Use systemctl daemon-reload or an equivalent command to reload unit
       configuration while the unit is already loaded. In this case all
       configuration settings are flushed out and replaced with the new
       configuration (which however might not be in effect immediately),
       however all runtime state is saved/restored.

[UNIT] SECTION OPTIONS         top

       The unit file may include a [Unit] section, which carries generic
       information about the unit that is not dependent on the type of unit:

       Description=
           A human readable name for the unit. This is used by systemd (and
           other UIs) as the label for the unit, so this string should
           identify the unit rather than describe it, despite the name.
           "Apache2 Web Server" is a good example. Bad examples are
           "high-performance light-weight HTTP server" (too generic) or
           "Apache2" (too specific and meaningless for people who do not
           know Apache).  systemd will use this string as a noun in status
           messages ("Starting description...", "Started description.",
           "Reached target description.", "Failed to start description."),
           so it should be capitalized, and should not be a full sentence or
           a phrase with a continuous verb. Bad examples include "exiting
           the container" or "updating the database once per day.".

       Documentation=
           A space-separated list of URIs referencing documentation for this
           unit or its configuration. Accepted are only URIs of the types
           "http://", "https://", "file:", "info:", "man:". For more
           information about the syntax of these URIs, see uri(7). The URIs
           should be listed in order of relevance, starting with the most
           relevant. It is a good idea to first reference documentation that
           explains what the unit's purpose is, followed by how it is
           configured, followed by any other related documentation. This
           option may be specified more than once, in which case the
           specified list of URIs is merged. If the empty string is assigned
           to this option, the list is reset and all prior assignments will
           have no effect.

       Wants=
           Configures requirement dependencies on other units. This option
           may be specified more than once or multiple space-separated units
           may be specified in one option in which case dependencies for all
           listed names will be created. Dependencies of this type may also
           be configured outside of the unit configuration file by adding a
           symlink to a .wants/ directory accompanying the unit file. For
           details, see above.

           Units listed in this option will be started if the configuring
           unit is. However, if the listed units fail to start or cannot be
           added to the transaction, this has no impact on the validity of
           the transaction as a whole, and this unit will still be started.
           This is the recommended way to hook the start-up of one unit to
           the start-up of another unit.

           Note that requirement dependencies do not influence the order in
           which services are started or stopped. This has to be configured
           independently with the After= or Before= options. If unit
           foo.service pulls in unit bar.service as configured with Wants=
           and no ordering is configured with After= or Before=, then both
           units will be started simultaneously and without any delay
           between them if foo.service is activated.

       Requires=
           Similar to Wants=, but declares a stronger dependency.
           Dependencies of this type may also be configured by adding a
           symlink to a .requires/ directory accompanying the unit file.

           If this unit gets activated, the units listed will be activated
           as well. If one of the other units fails to activate, and an
           ordering dependency After= on the failing unit is set, this unit
           will not be started. Besides, with or without specifying After=,
           this unit will be stopped if one of the other units is explicitly
           stopped.

           Often, it is a better choice to use Wants= instead of Requires=
           in order to achieve a system that is more robust when dealing
           with failing services.

           Note that this dependency type does not imply that the other unit
           always has to be in active state when this unit is running.
           Specifically: failing condition checks (such as
           ConditionPathExists=, ConditionPathIsSymbolicLink=, ... — see
           below) do not cause the start job of a unit with a Requires=
           dependency on it to fail. Also, some unit types may deactivate on
           their own (for example, a service process may decide to exit
           cleanly, or a device may be unplugged by the user), which is not
           propagated to units having a Requires= dependency. Use the
           BindsTo= dependency type together with After= to ensure that a
           unit may never be in active state without a specific other unit
           also in active state (see below).

       Requisite=
           Similar to Requires=. However, if the units listed here are not
           started already, they will not be started and the starting of
           this unit will fail immediately.  Requisite= does not imply an
           ordering dependency, even if both units are started in the same
           transaction. Hence this setting should usually be combined with
           After=, to ensure this unit is not started before the other unit.

           When Requisite=b.service is used on a.service, this dependency
           will show as RequisiteOf=a.service in property listing of
           b.service.  RequisiteOf= dependency cannot be specified directly.

       BindsTo=
           Configures requirement dependencies, very similar in style to
           Requires=. However, this dependency type is stronger: in addition
           to the effect of Requires= it declares that if the unit bound to
           is stopped, this unit will be stopped too. This means a unit
           bound to another unit that suddenly enters inactive state will be
           stopped too. Units can suddenly, unexpectedly enter inactive
           state for different reasons: the main process of a service unit
           might terminate on its own choice, the backing device of a device
           unit might be unplugged or the mount point of a mount unit might
           be unmounted without involvement of the system and service
           manager.

           When used in conjunction with After= on the same unit the
           behaviour of BindsTo= is even stronger. In this case, the unit
           bound to strictly has to be in active state for this unit to also
           be in active state. This not only means a unit bound to another
           unit that suddenly enters inactive state, but also one that is
           bound to another unit that gets skipped due to a failed condition
           check (such as ConditionPathExists=,
           ConditionPathIsSymbolicLink=, ... — see below) will be stopped,
           should it be running. Hence, in many cases it is best to combine
           BindsTo= with After=.

           When BindsTo=b.service is used on a.service, this dependency will
           show as BoundBy=a.service in property listing of b.service.
           BoundBy= dependency cannot be specified directly.

       PartOf=
           Configures dependencies similar to Requires=, but limited to
           stopping and restarting of units. When systemd stops or restarts
           the units listed here, the action is propagated to this unit.
           Note that this is a one-way dependency — changes to this unit do
           not affect the listed units.

           When PartOf=b.service is used on a.service, this dependency will
           show as ConsistsOf=a.service in property listing of b.service.
           ConsistsOf= dependency cannot be specified directly.

       Conflicts=
           A space-separated list of unit names. Configures negative
           requirement dependencies. If a unit has a Conflicts= setting on
           another unit, starting the former will stop the latter and vice
           versa.

           Note that this setting does not imply an ordering dependency,
           similarly to the Wants= and Requires= dependencies described
           above. This means that to ensure that the conflicting unit is
           stopped before the other unit is started, an After= or Before=
           dependency must be declared. It doesn't matter which of the two
           ordering dependencies is used, because stop jobs are always
           ordered before start jobs, see the discussion in Before=/After=
           below.

           If unit A that conflicts with unit B is scheduled to be started
           at the same time as B, the transaction will either fail (in case
           both are required parts of the transaction) or be modified to be
           fixed (in case one or both jobs are not a required part of the
           transaction). In the latter case, the job that is not required
           will be removed, or in case both are not required, the unit that
           conflicts will be started and the unit that is conflicted is
           stopped.

       Before=, After=
           These two settings expect a space-separated list of unit names.
           They may be specified more than once, in which case dependencies
           for all listed names are created.

           Those two settings configure ordering dependencies between units.
           If unit foo.service contains the setting Before=bar.service and
           both units are being started, bar.service's start-up is delayed
           until foo.service has finished starting up.  After= is the
           inverse of Before=, i.e. while Before= ensures that the
           configured unit is started before the listed unit begins starting
           up, After= ensures the opposite, that the listed unit is fully
           started up before the configured unit is started.

           When two units with an ordering dependency between them are shut
           down, the inverse of the start-up order is applied. I.e. if a
           unit is configured with After= on another unit, the former is
           stopped before the latter if both are shut down. Given two units
           with any ordering dependency between them, if one unit is shut
           down and the other is started up, the shutdown is ordered before
           the start-up. It doesn't matter if the ordering dependency is
           After= or Before=, in this case. It also doesn't matter which of
           the two is shut down, as long as one is shut down and the other
           is started up; the shutdown is ordered before the start-up in all
           cases. If two units have no ordering dependencies between them,
           they are shut down or started up simultaneously, and no ordering
           takes place. It depends on the unit type when precisely a unit
           has finished starting up. Most importantly, for service units
           start-up is considered completed for the purpose of
           Before=/After= when all its configured start-up commands have
           been invoked and they either failed or reported start-up success.
           Note that this does includes ExecStartPost= (or ExecStopPost= for
           the shutdown case).

           Note that those settings are independent of and orthogonal to the
           requirement dependencies as configured by Requires=, Wants=,
           Requisite=, or BindsTo=. It is a common pattern to include a unit
           name in both the After= and Wants= options, in which case the
           unit listed will be started before the unit that is configured
           with these options.

           Note that Before= dependencies on device units have no effect and
           are not supported. Devices generally become available as a result
           of an external hotplug event, and systemd creates the
           corresponding device unit without delay.

       OnFailure=
           A space-separated list of one or more units that are activated
           when this unit enters the "failed" state. A service unit using
           Restart= enters the failed state only after the start limits are
           reached.

       PropagatesReloadTo=, ReloadPropagatedFrom=
           A space-separated list of one or more units where reload requests
           on this unit will be propagated to, or reload requests on the
           other unit will be propagated to this unit, respectively. Issuing
           a reload request on a unit will automatically also enqueue a
           reload request on all units that the reload request shall be
           propagated to via these two settings.

       JoinsNamespaceOf=
           For units that start processes (such as service units), lists one
           or more other units whose network and/or temporary file namespace
           to join. This only applies to unit types which support the
           PrivateNetwork=, NetworkNamespacePath= and PrivateTmp= directives
           (see systemd.exec(5) for details). If a unit that has this
           setting set is started, its processes will see the same /tmp/,
           /var/tmp/ and network namespace as one listed unit that is
           started. If multiple listed units are already started, it is not
           defined which namespace is joined. Note that this setting only
           has an effect if PrivateNetwork=/NetworkNamespacePath= and/or
           PrivateTmp= is enabled for both the unit that joins the namespace
           and the unit whose namespace is joined.

       RequiresMountsFor=
           Takes a space-separated list of absolute paths. Automatically
           adds dependencies of type Requires= and After= for all mount
           units required to access the specified path.

           Mount points marked with noauto are not mounted automatically
           through local-fs.target, but are still honored for the purposes
           of this option, i.e. they will be pulled in by this unit.

       OnFailureJobMode=
           Takes a value of "fail", "replace", "replace-irreversibly",
           "isolate", "flush", "ignore-dependencies" or
           "ignore-requirements". Defaults to "replace". Specifies how the
           units listed in OnFailure= will be enqueued. See systemctl(1)'s
           --job-mode= option for details on the possible values. If this is
           set to "isolate", only a single unit may be listed in OnFailure=.

       IgnoreOnIsolate=
           Takes a boolean argument. If true, this unit will not be stopped
           when isolating another unit. Defaults to false for service,
           target, socket, timer, and path units, and true for slice, scope,
           device, swap, mount, and automount units.

       StopWhenUnneeded=
           Takes a boolean argument. If true, this unit will be stopped when
           it is no longer used. Note that, in order to minimize the work to
           be executed, systemd will not stop units by default unless they
           are conflicting with other units, or the user explicitly
           requested their shut down. If this option is set, a unit will be
           automatically cleaned up if no other active unit requires it.
           Defaults to false.

       RefuseManualStart=, RefuseManualStop=
           Takes a boolean argument. If true, this unit can only be
           activated or deactivated indirectly. In this case, explicit
           start-up or termination requested by the user is denied, however
           if it is started or stopped as a dependency of another unit,
           start-up or termination will succeed. This is mostly a safety
           feature to ensure that the user does not accidentally activate
           units that are not intended to be activated explicitly, and not
           accidentally deactivate units that are not intended to be
           deactivated. These options default to false.

       AllowIsolate=
           Takes a boolean argument. If true, this unit may be used with the
           systemctl isolate command. Otherwise, this will be refused. It
           probably is a good idea to leave this disabled except for target
           units that shall be used similar to runlevels in SysV init
           systems, just as a precaution to avoid unusable system states.
           This option defaults to false.

       DefaultDependencies=
           Takes a boolean argument. If yes, (the default), a few default
           dependencies will implicitly be created for the unit. The actual
           dependencies created depend on the unit type. For example, for
           service units, these dependencies ensure that the service is
           started only after basic system initialization is completed and
           is properly terminated on system shutdown. See the respective man
           pages for details. Generally, only services involved with early
           boot or late shutdown should set this option to no. It is highly
           recommended to leave this option enabled for the majority of
           common units. If set to no, this option does not disable all
           implicit dependencies, just non-essential ones.

       CollectMode=
           Tweaks the "garbage collection" algorithm for this unit. Takes
           one of inactive or inactive-or-failed. If set to inactive the
           unit will be unloaded if it is in the inactive state and is not
           referenced by clients, jobs or other units — however it is not
           unloaded if it is in the failed state. In failed mode, failed
           units are not unloaded until the user invoked systemctl
           reset-failed on them to reset the failed state, or an equivalent
           command. This behaviour is altered if this option is set to
           inactive-or-failed: in this case the unit is unloaded even if the
           unit is in a failed state, and thus an explicitly resetting of
           the failed state is not necessary. Note that if this mode is used
           unit results (such as exit codes, exit signals, consumed
           resources, ...) are flushed out immediately after the unit
           completed, except for what is stored in the logging subsystem.
           Defaults to inactive.

       FailureAction=, SuccessAction=
           Configure the action to take when the unit stops and enters a
           failed state or inactive state. Takes one of none, reboot,
           reboot-force, reboot-immediate, poweroff, poweroff-force,
           poweroff-immediate, exit, and exit-force. In system mode, all
           options are allowed. In user mode, only none, exit, and
           exit-force are allowed. Both options default to none.

           If none is set, no action will be triggered.  reboot causes a
           reboot following the normal shutdown procedure (i.e. equivalent
           to systemctl reboot).  reboot-force causes a forced reboot which
           will terminate all processes forcibly but should cause no dirty
           file systems on reboot (i.e. equivalent to systemctl reboot -f)
           and reboot-immediate causes immediate execution of the reboot(2)
           system call, which might result in data loss (i.e. equivalent to
           systemctl reboot -ff). Similarly, poweroff, poweroff-force,
           poweroff-immediate have the effect of powering down the system
           with similar semantics.  exit causes the manager to exit
           following the normal shutdown procedure, and exit-force causes it
           terminate without shutting down services. When exit or exit-force
           is used by default the exit status of the main process of the
           unit (if this applies) is returned from the service manager.
           However, this may be overridden with
           FailureActionExitStatus=/SuccessActionExitStatus=, see below.

       FailureActionExitStatus=, SuccessActionExitStatus=
           Controls the exit status to propagate back to an invoking
           container manager (in case of a system service) or service
           manager (in case of a user manager) when the
           FailureAction=/SuccessAction= are set to exit or exit-force and
           the action is triggered. By default the exit status of the main
           process of the triggering unit (if this applies) is propagated.
           Takes a value in the range 0...255 or the empty string to request
           default behaviour.

       JobTimeoutSec=, JobRunningTimeoutSec=
           When a job for this unit is queued, a timeout JobTimeoutSec= may
           be configured. Similarly, JobRunningTimeoutSec= starts counting
           when the queued job is actually started. If either time limit is
           reached, the job will be cancelled, the unit however will not
           change state or even enter the "failed" mode. This value defaults
           to "infinity" (job timeouts disabled), except for device units
           (JobRunningTimeoutSec= defaults to DefaultTimeoutStartSec=). NB:
           this timeout is independent from any unit-specific timeout (for
           example, the timeout set with TimeoutStartSec= in service units)
           as the job timeout has no effect on the unit itself, only on the
           job that might be pending for it. Or in other words:
           unit-specific timeouts are useful to abort unit state changes,
           and revert them. The job timeout set with this option however is
           useful to abort only the job waiting for the unit state to
           change.

       JobTimeoutAction=, JobTimeoutRebootArgument=
           JobTimeoutAction= optionally configures an additional action to
           take when the timeout is hit, see description of JobTimeoutSec=
           and JobRunningTimeoutSec= above. It takes the same values as
           StartLimitAction=. Defaults to none.  JobTimeoutRebootArgument=
           configures an optional reboot string to pass to the reboot(2)
           system call.

       StartLimitIntervalSec=interval, StartLimitBurst=burst
           Configure unit start rate limiting. Units which are started more
           than burst times within an interval time interval are not
           permitted to start any more. Use StartLimitIntervalSec= to
           configure the checking interval (defaults to
           DefaultStartLimitIntervalSec= in manager configuration file, set
           it to 0 to disable any kind of rate limiting). Use
           StartLimitBurst= to configure how many starts per interval are
           allowed (defaults to DefaultStartLimitBurst= in manager
           configuration file). These configuration options are particularly
           useful in conjunction with the service setting Restart= (see
           systemd.service(5)); however, they apply to all kinds of starts
           (including manual), not just those triggered by the Restart=
           logic. Note that units which are configured for Restart= and
           which reach the start limit are not attempted to be restarted
           anymore; however, they may still be restarted manually at a later
           point, after the interval has passed. From this point on, the
           restart logic is activated again. Note that systemctl
           reset-failed will cause the restart rate counter for a service to
           be flushed, which is useful if the administrator wants to
           manually start a unit and the start limit interferes with that.
           Note that this rate-limiting is enforced after any unit condition
           checks are executed, and hence unit activations with failing
           conditions do not count towards this rate limit. This setting
           does not apply to slice, target, device, and scope units, since
           they are unit types whose activation may either never fail, or
           may succeed only a single time.

           When a unit is unloaded due to the garbage collection logic (see
           above) its rate limit counters are flushed out too. This means
           that configuring start rate limiting for a unit that is not
           referenced continuously has no effect.

       StartLimitAction=
           Configure an additional action to take if the rate limit
           configured with StartLimitIntervalSec= and StartLimitBurst= is
           hit. Takes the same values as the FailureAction=/SuccessAction=
           settings. If none is set, hitting the rate limit will trigger no
           action except that the start will not be permitted. Defaults to
           none.

       RebootArgument=
           Configure the optional argument for the reboot(2) system call if
           StartLimitAction= or FailureAction= is a reboot action. This
           works just like the optional argument to systemctl reboot
           command.

       SourcePath=
           A path to a configuration file this unit has been generated from.
           This is primarily useful for implementation of generator tools
           that convert configuration from an external configuration file
           format into native unit files. This functionality should not be
           used in normal units.

   Conditions and Asserts
       Unit files may also include a number of Condition...= and Assert...=
       settings. Before the unit is started, systemd will verify that the
       specified conditions are true. If not, the starting of the unit will
       be (mostly silently) skipped. Failing conditions will not result in
       the unit being moved into the "failed" state. The conditions are
       checked at the time the queued start job is to be executed. The
       ordering dependencies are still respected, so other units are still
       pulled in and ordered as if this unit was successfully activated. Use
       condition expressions in order to skip units that do not apply to the
       local system, for example because the kernel or runtime environment
       doesn't require their functionality.

       If multiple conditions are specified, the unit will be executed if
       all of them apply (i.e. a logical AND is applied). Condition checks
       can use a pipe symbol ("|") after the equals sign
       ("Condition...=|..."), which causes the condition becomes a
       triggering condition. If at least one triggering condition is defined
       for a unit, then the unit will be executed if at least one of the
       triggering conditions apply and all of the non-triggering conditions.
       If you prefix an argument with the pipe symbol and an exclamation
       mark, the pipe symbol must be passed first, the exclamation second.
       If any of these options is assigned the empty string, the list of
       conditions is reset completely, all previous condition settings (of
       any kind) will have no effect.

       The AssertArchitecture=, AssertVirtualization=, ... options provide a
       similar mechanism that causes the job to fail (instead of being
       skipped). The failed check is logged. Units with failed conditions
       are considered to be in a clean state and will be garbage collected
       if they are not referenced. This means that when queried, the
       condition failure may or may not show up in the state of the unit.

       Note that neither assertion nor condition expressions result in unit
       state changes. Also note that both are checked at the time the job is
       to be executed, i.e. long after depending jobs and it itself were
       queued. Thus, neither condition nor assertion expressions are
       suitable for conditionalizing unit dependencies.

       The condition verb of systemd-analyze(1) can be used to test
       condition and assert expressions.

       Except for ConditionPathIsSymbolicLink=, all path checks follow
       symlinks.

       ConditionArchitecture=
           Check whether the system is running on a specific architecture.
           Takes one of "x86", "x86-64", "ppc", "ppc-le", "ppc64",
           "ppc64-le", "ia64", "parisc", "parisc64", "s390", "s390x",
           "sparc", "sparc64", "mips", "mips-le", "mips64", "mips64-le",
           "alpha", "arm", "arm-be", "arm64", "arm64-be", "sh", "sh64",
           "m68k", "tilegx", "cris", "arc", "arc-be", or "native".

           The architecture is determined from the information returned by
           uname(2) and is thus subject to personality(2). Note that a
           Personality= setting in the same unit file has no effect on this
           condition. A special architecture name "native" is mapped to the
           architecture the system manager itself is compiled for. The test
           may be negated by prepending an exclamation mark.

       ConditionVirtualization=
           Check whether the system is executed in a virtualized environment
           and optionally test whether it is a specific implementation.
           Takes either boolean value to check if being executed in any
           virtualized environment, or one of "vm" and "container" to test
           against a generic type of virtualization solution, or one of
           "qemu", "kvm", "zvm", "vmware", "microsoft", "oracle", "powervm",
           "xen", "bochs", "uml", "bhyve", "qnx", "openvz", "lxc",
           "lxc-libvirt", "systemd-nspawn", "docker", "podman", "rkt",
           "wsl", "proot", "pouch", "acrn" to test against a specific
           implementation, or "private-users" to check whether we are
           running in a user namespace. See systemd-detect-virt(1) for a
           full list of known virtualization technologies and their
           identifiers. If multiple virtualization technologies are nested,
           only the innermost is considered. The test may be negated by
           prepending an exclamation mark.

       ConditionHost=
           ConditionHost= may be used to match against the hostname or
           machine ID of the host. This either takes a hostname string
           (optionally with shell style globs) which is tested against the
           locally set hostname as returned by gethostname(2), or a machine
           ID formatted as string (see machine-id(5)). The test may be
           negated by prepending an exclamation mark.

       ConditionKernelCommandLine=
           ConditionKernelCommandLine= may be used to check whether a
           specific kernel command line option is set (or if prefixed with
           the exclamation mark — unset). The argument must either be a
           single word, or an assignment (i.e. two words, separated by "=").
           In the former case the kernel command line is searched for the
           word appearing as is, or as left hand side of an assignment. In
           the latter case, the exact assignment is looked for with right
           and left hand side matching. This operates on the kernel command
           line communicated to userspace via /proc/cmdline, except when the
           service manager is invoked as payload of a container manager, in
           which case the command line of PID 1 is used instead (i.e.
           /proc/1/cmdline).

       ConditionKernelVersion=
           ConditionKernelVersion= may be used to check whether the kernel
           version (as reported by uname -r) matches a certain expression
           (or if prefixed with the exclamation mark does not match it). The
           argument must be a list of (potentially quoted) expressions. For
           each of the expressions, if it starts with one of "<", "<=", "=",
           "!=", ">=", ">" a relative version comparison is done, otherwise
           the specified string is matched with shell-style globs.

           Note that using the kernel version string is an unreliable way to
           determine which features are supported by a kernel, because of
           the widespread practice of backporting drivers, features, and
           fixes from newer upstream kernels into older versions provided by
           distributions. Hence, this check is inherently unportable and
           should not be used for units which may be used on different
           distributions.

       ConditionEnvironment=
           ConditionEnvironment= may be used to check whether a specific
           environment variable is set (or if prefixed with the exclamation
           mark — unset) in the service manager's environment block. The
           argument may be a single word, to check if the variable with this
           name is defined in the environment block, or an assignment
           ("name=value"), to check if the variable with this exact value is
           defined. Note that the environment block of the service manager
           itself is checked, i.e. not any variables defined with
           Environment= or EnvironmentFile=, as described above. This is
           particularly useful when the service manager runs inside a
           containerized environment or as per-user service manager, in
           order to check for variables passed in by the enclosing container
           manager or PAM.

       ConditionSecurity=
           ConditionSecurity= may be used to check whether the given
           security technology is enabled on the system. Currently, the
           recognized values are "selinux", "apparmor", "tomoyo", "ima",
           "smack", "audit" and "uefi-secureboot". The test may be negated
           by prepending an exclamation mark.

       ConditionCapability=
           Check whether the given capability exists in the capability
           bounding set of the service manager (i.e. this does not check
           whether capability is actually available in the permitted or
           effective sets, see capabilities(7) for details). Pass a
           capability name such as "CAP_MKNOD", possibly prefixed with an
           exclamation mark to negate the check.

       ConditionACPower=
           Check whether the system has AC power, or is exclusively battery
           powered at the time of activation of the unit. This takes a
           boolean argument. If set to "true", the condition will hold only
           if at least one AC connector of the system is connected to a
           power source, or if no AC connectors are known. Conversely, if
           set to "false", the condition will hold only if there is at least
           one AC connector known and all AC connectors are disconnected
           from a power source.

       ConditionNeedsUpdate=
           Takes one of /var/ or /etc/ as argument, possibly prefixed with a
           "!"  (to invert the condition). This condition may be used to
           conditionalize units on whether the specified directory requires
           an update because /usr/'s modification time is newer than the
           stamp file .updated in the specified directory. This is useful to
           implement offline updates of the vendor operating system
           resources in /usr/ that require updating of /etc/ or /var/ on the
           next following boot. Units making use of this condition should
           order themselves before systemd-update-done.service(8), to make
           sure they run before the stamp file's modification time gets
           reset indicating a completed update.

           If the systemd.condition-needs-update= option is specified on the
           kernel command line (taking a boolean), it will override the
           result of this condition check, taking precedence over any file
           modification time checks. If it is used
           systemd-update-done.service will not have immediate effect on any
           following ConditionNeedsUpdate= checks, until the system is
           rebooted where the kernel command line option is not specified
           anymore.

       ConditionFirstBoot=
           Takes a boolean argument. This condition may be used to
           conditionalize units on whether the system is booting up for the
           first time. This roughly means that /etc/ is unpopulated (for
           details, see "First Boot Semantics" in machine-id(5)). This may
           be used to populate /etc/ on the first boot after factory reset,
           or when a new system instance boots up for the first time.

           For robustness, units with ConditionFirstBoot=yes should order
           themselves before first-boot-complete.target and pull in this
           passive target with Wants=. This ensures that in a case of an
           aborted first boot, these units will be re-run during the next
           system startup.

           If the systemd.condition-first-boot= option is specified on the
           kernel command line (taking a boolean), it will override the
           result of this condition check, taking precedence over
           /etc/machine-id existence checks.

       ConditionPathExists=
           Check for the exists of a file. If the specified absolute path
           name does not exist, the condition will fail. If the absolute
           path name passed to ConditionPathExists= is prefixed with an
           exclamation mark ("!"), the test is negated, and the unit is only
           started if the path does not exist.

       ConditionPathExistsGlob=
           ConditionPathExistsGlob= is similar to ConditionPathExists=, but
           checks for the existence of at least one file or directory
           matching the specified globbing pattern.

       ConditionPathIsDirectory=
           ConditionPathIsDirectory= is similar to ConditionPathExists= but
           verifies that a certain path exists and is a directory.

       ConditionPathIsSymbolicLink=
           ConditionPathIsSymbolicLink= is similar to ConditionPathExists=
           but verifies that a certain path exists and is a symbolic link.

       ConditionPathIsMountPoint=
           ConditionPathIsMountPoint= is similar to ConditionPathExists= but
           verifies that a certain path exists and is a mount point.

       ConditionPathIsReadWrite=
           ConditionPathIsReadWrite= is similar to ConditionPathExists= but
           verifies that the underlying file system is readable and writable
           (i.e. not mounted read-only).

       ConditionPathIsEncrypted=
           ConditionPathIsEncrypted= is similar to ConditionPathExists= but
           verifies that the underlying file system's backing block device
           is encrypted using dm-crypt/LUKS. Note that this check does not
           cover ext4 per-directory encryption, and only detects block level
           encryption. Moreover, if the specified path resides on a file
           system on top of a loopback block device, only encryption above
           the loopback device is detected. It is not detected whether the
           file system backing the loopback block device is encrypted.

       ConditionDirectoryNotEmpty=
           ConditionDirectoryNotEmpty= is similar to ConditionPathExists=
           but verifies that a certain path exists and is a non-empty
           directory.

       ConditionFileNotEmpty=
           ConditionFileNotEmpty= is similar to ConditionPathExists= but
           verifies that a certain path exists and refers to a regular file
           with a non-zero size.

       ConditionFileIsExecutable=
           ConditionFileIsExecutable= is similar to ConditionPathExists= but
           verifies that a certain path exists, is a regular file, and
           marked executable.

       ConditionUser=
           ConditionUser= takes a numeric "UID", a UNIX user name, or the
           special value "@system". This condition may be used to check
           whether the service manager is running as the given user. The
           special value "@system" can be used to check if the user id is
           within the system user range. This option is not useful for
           system services, as the system manager exclusively runs as the
           root user, and thus the test result is constant.

       ConditionGroup=
           ConditionGroup= is similar to ConditionUser= but verifies that
           the service manager's real or effective group, or any of its
           auxiliary groups, match the specified group or GID. This setting
           does not support the special value "@system".

       ConditionControlGroupController=
           Verify that the given cgroup controller (eg.  "cpu") is available
           for use on the system. For example, a particular controller may
           not be available if it was disabled on the kernel command line
           with cgroup_disable=controller. Multiple controllers may be
           passed with a space separating them; in this case the condition
           will only pass if all listed controllers are available for use.
           Controllers unknown to systemd are ignored. Valid controllers are
           "cpu", "cpuacct", "io", "blkio", "memory", "devices", and "pids".

       ConditionMemory=
           Verify that the specified amount of system memory is available to
           the current system. Takes a memory size in bytes as argument,
           optionally prefixed with a comparison operator "<", "<=", "=",
           "!=", ">=", ">". On bare-metal systems compares the amount of
           physical memory in the system with the specified size, adhering
           to the specified comparison operator. In containers compares the
           amount of memory assigned to the container instead.

       ConditionCPUs=
           Verify that the specified number of CPUs is available to the
           current system. Takes a number of CPUs as argument, optionally
           prefixed with a comparison operator "<", "<=", "=", "!=", ">=",
           ">". Compares the number of CPUs in the CPU affinity mask
           configured of the service manager itself with the specified
           number, adhering to the specified comparison operator. On
           physical systems the number of CPUs in the affinity mask of the
           service manager usually matches the number of physical CPUs, but
           in special and virtual environments might differ. In particular,
           in containers the affinity mask usually matches the number of
           CPUs assigned to the container and not the physically available
           ones.

       AssertArchitecture=, AssertVirtualization=, AssertHost=,
       AssertKernelCommandLine=, AssertKernelVersion=, AssertSecurity=,
       AssertCapability=, AssertACPower=, AssertNeedsUpdate=,
       AssertFirstBoot=, AssertPathExists=, AssertPathExistsGlob=,
       AssertPathIsDirectory=, AssertPathIsSymbolicLink=,
       AssertPathIsMountPoint=, AssertPathIsReadWrite=,
       AssertDirectoryNotEmpty=, AssertFileNotEmpty=,
       AssertFileIsExecutable=, AssertUser=, AssertGroup=,
       AssertControlGroupController=
           Similar to the ConditionArchitecture=, ConditionVirtualization=,
           ..., condition settings described above, these settings add
           assertion checks to the start-up of the unit. However, unlike the
           conditions settings, any assertion setting that is not met
           results in failure of the start job (which means this is logged
           loudly). Note that hitting a configured assertion does not cause
           the unit to enter the "failed" state (or in fact result in any
           state change of the unit), it affects only the job queued for it.
           Use assertion expressions for units that cannot operate when
           specific requirements are not met, and when this is something the
           administrator or user should look into.

MAPPING OF UNIT PROPERTIES TO THEIR INVERSES         top

       Unit settings that create a relationship with a second unit usually
       show up in properties of both units, for example in systemctl show
       output. In some cases the name of the property is the same as the
       name of the configuration setting, but not always. This table lists
       the properties that are shown on two units which are connected
       through some dependency, and shows which property on "source" unit
       corresponds to which property on the "target" unit.

       Table 3.  Forward and reverse unit properties
       ┌──────────────────────┬───────────────────────┬───────────────────────────────┐
       │"Forward"             "Reverse"             Where used                    │
       │property              property              │                               │
       ├──────────────────────┼───────────────────────┼───────────────────────────────┤
       │Before=After=                │                               │
       ├──────────────────────┼───────────────────────┤ [Unit] section                │
       │After=Before=               │                               │
       ├──────────────────────┼───────────────────────┼────────────────┬──────────────┤
       │Requires=RequiredBy=           │ [Unit] section │ [Install]    │
       │                      │                       │                │ section      │
       ├──────────────────────┼───────────────────────┼────────────────┼──────────────┤
       │Wants=WantedBy=             │ [Unit] section │ [Install]    │
       │                      │                       │                │ section      │
       ├──────────────────────┼───────────────────────┼────────────────┼──────────────┤
       │PartOf=ConsistsOf=           │ [Unit] section │ an automatic │
       │                      │                       │                │ property     │
       ├──────────────────────┼───────────────────────┼────────────────┼──────────────┤
       │BindsTo=BoundBy=              │ [Unit] section │ an automatic │
       │                      │                       │                │ property     │
       ├──────────────────────┼───────────────────────┼────────────────┼──────────────┤
       │Requisite=RequisiteOf=          │ [Unit] section │ an automatic │
       │                      │                       │                │ property     │
       ├──────────────────────┼───────────────────────┼────────────────┴──────────────┤
       │Triggers=TriggeredBy=          │ Automatic properties, see     │
       │                      │                       │ notes below                   │
       ├──────────────────────┼───────────────────────┼────────────────┬──────────────┤
       │Conflicts=ConflictedBy=         │ [Unit] section │ an automatic │
       │                      │                       │                │ property     │
       ├──────────────────────┼───────────────────────┼────────────────┴──────────────┤
       │PropagatesReloadTo=ReloadPropagatedFrom= │                               │
       ├──────────────────────┼───────────────────────┤ [Unit] section                │
       │ReloadPropagatedFrom=PropagatesReloadTo=   │                               │
       ├──────────────────────┼───────────────────────┼────────────────┬──────────────┤
       │Following=            │ n/a                   │ An automatic   │              │
       │                      │                       │ property       │              │
       └──────────────────────┴───────────────────────┴────────────────┴──────────────┘

       Note: WantedBy= and RequiredBy= are used in the [Install] section to
       create symlinks in .wants/ and .requires/ directories. They cannot be
       used directly as a unit configuration setting.

       Note: ConsistsOf=, BoundBy=, RequisiteOf=, ConflictedBy= are created
       implicitly along with their reverses and cannot be specified
       directly.

       Note: Triggers= is created implicitly between a socket, path unit, or
       an automount unit, and the unit they activate. By default a unit with
       the same name is triggered, but this can be overridden using
       Sockets=, Service=, and Unit= settings. See systemd.service(5),
       systemd.socket(5), systemd.path(5), and systemd.automount(5) for
       details.  TriggeredBy= is created implicitly on the triggered unit.

       Note: Following= is used to group device aliases and points to the
       "primary" device unit that systemd is using to track device state,
       usually corresponding to a sysfs path. It does not show up in the
       "target" unit.

[INSTALL] SECTION OPTIONS         top

       Unit files may include an [Install] section, which carries
       installation information for the unit. This section is not
       interpreted by systemd(1) during runtime; it is used by the enable
       and disable commands of the systemctl(1) tool during installation of
       a unit.

       Alias=
           A space-separated list of additional names this unit shall be
           installed under. The names listed here must have the same suffix
           (i.e. type) as the unit filename. This option may be specified
           more than once, in which case all listed names are used. At
           installation time, systemctl enable will create symlinks from
           these names to the unit filename. Note that not all unit types
           support such alias names, and this setting is not supported for
           them. Specifically, mount, slice, swap, and automount units do
           not support aliasing.

       WantedBy=, RequiredBy=
           This option may be used more than once, or a space-separated list
           of unit names may be given. A symbolic link is created in the
           .wants/ or .requires/ directory of each of the listed units when
           this unit is installed by systemctl enable. This has the effect
           that a dependency of type Wants= or Requires= is added from the
           listed unit to the current unit. The primary result is that the
           current unit will be started when the listed unit is started. See
           the description of Wants= and Requires= in the [Unit] section for
           details.

           WantedBy=foo.service in a service bar.service is mostly
           equivalent to Alias=foo.service.wants/bar.service in the same
           file. In case of template units, systemctl enable must be called
           with an instance name, and this instance will be added to the
           .wants/ or .requires/ list of the listed unit. E.g.
           WantedBy=getty.target in a service getty@.service will result in
           systemctl enable getty@tty2.service creating a
           getty.target.wants/getty@tty2.service link to getty@.service.

       Also=
           Additional units to install/deinstall when this unit is
           installed/deinstalled. If the user requests
           installation/deinstallation of a unit with this option
           configured, systemctl enable and systemctl disable will
           automatically install/uninstall units listed in this option as
           well.

           This option may be used more than once, or a space-separated list
           of unit names may be given.

       DefaultInstance=
           In template unit files, this specifies for which instance the
           unit shall be enabled if the template is enabled without any
           explicitly set instance. This option has no effect in
           non-template unit files. The specified string must be usable as
           instance identifier.

       The following specifiers are interpreted in the Install section: %n,
       %N, %p, %i, %j, %g, %G, %U, %u, %m, %H, %b, %v. For their meaning see
       the next section.

SPECIFIERS         top

       Many settings resolve specifiers which may be used to write generic
       unit files referring to runtime or unit parameters that are replaced
       when the unit files are loaded. Specifiers must be known and
       resolvable for the setting to be valid. The following specifiers are
       understood:

       Table 4. Specifiers available in unit files
       ┌──────────┬─────────────────────┬────────────────────────┐
       │Specifier Meaning             Details                │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%a"      │ Architecture        │ A short string         │
       │          │                     │ identifying the        │
       │          │                     │ architecture of the    │
       │          │                     │ local system. A        │
       │          │                     │ string such as x86,    │
       │          │                     │ x86-64 or arm64.       │
       │          │                     │ See the                │
       │          │                     │ architectures          │
       │          │                     │ defined for            │
       │          │                     │ ConditionArchitecture= │
       │          │                     │ above for a full       │
       │          │                     │ list.                  │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%b"      │ Boot ID             │ The boot ID of the     │
       │          │                     │ running system,        │
       │          │                     │ formatted as string.   │
       │          │                     │ See random(4) for more │
       │          │                     │ information.           │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%B"      │ Operating system    │ The operating system   │
       │          │ build ID            │ build identifier of    │
       │          │                     │ the running system, as │
       │          │                     │ read from the          │
       │          │                     │ BUILD_ID= field of     │
       │          │                     │ /etc/os-release. If    │
       │          │                     │ not set, resolves to   │
       │          │                     │ an empty string. See   │
       │          │                     │ os-release(5) for more │
       │          │                     │ information.           │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%C"      │ Cache directory     │ This is either         │
       │          │ root                │ /var/cache (for the    │
       │          │                     │ system manager) or the │
       │          │                     │ path "$XDG_CACHE_HOME" │
       │          │                     │ resolves to (for user  │
       │          │                     │ managers).             │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%E"      │ Configuration       │ This is either /etc/   │
       │          │ directory root      │ (for the system        │
       │          │                     │ manager) or the path   │
       │          │                     │ "$XDG_CONFIG_HOME"     │
       │          │                     │ resolves to (for user  │
       │          │                     │ managers).             │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%f"      │ Unescaped filename  │ This is either the     │
       │          │                     │ unescaped instance     │
       │          │                     │ name (if applicable)   │
       │          │                     │ with / prepended (if   │
       │          │                     │ applicable), or the    │
       │          │                     │ unescaped prefix name  │
       │          │                     │ prepended with /. This │
       │          │                     │ implements unescaping  │
       │          │                     │ according to the rules │
       │          │                     │ for escaping absolute  │
       │          │                     │ file system paths      │
       │          │                     │ discussed above.       │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%h"      │ User home directory │ This is the home       │
       │          │                     │ directory of the user  │
       │          │                     │ running the service    │
       │          │                     │ manager instance. In   │
       │          │                     │ case of the system     │
       │          │                     │ manager this resolves  │
       │          │                     │ to "/root".            │
       │          │                     │                        │
       │          │                     │ Note that this setting │
       │          │                     │ is not influenced by   │
       │          │                     │ the User= setting      │
       │          │                     │ configurable in the    │
       │          │                     │ [Service] section of   │
       │          │                     │ the service unit.      │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%H"      │ Host name           │ The hostname of the    │
       │          │                     │ running system at the  │
       │          │                     │ point in time the unit │
       │          │                     │ configuration is       │
       │          │                     │ loaded.                │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%l"      │ Short host name     │ The hostname of the    │
       │          │                     │ running system at the  │
       │          │                     │ point in time the unit │
       │          │                     │ configuration is       │
       │          │                     │ loaded, truncated at   │
       │          │                     │ the first dot to       │
       │          │                     │ remove any domain      │
       │          │                     │ component.             │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%i"      │ Instance name       │ For instantiated units │
       │          │                     │ this is the string     │
       │          │                     │ between the first "@"  │
       │          │                     │ character and the type │
       │          │                     │ suffix. Empty for      │
       │          │                     │ non-instantiated       │
       │          │                     │ units.                 │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%I"      │ Unescaped instance  │ Same as "%i", but with │
       │          │ name                │ escaping undone.       │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%j"      │ Final component of  │ This is the string     │
       │          │ the prefix          │ between the last "-"   │
       │          │                     │ and the end of the     │
       │          │                     │ prefix name. If there  │
       │          │                     │ is no "-", this is the │
       │          │                     │ same as "%p".          │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%J"      │ Unescaped final     │ Same as "%j", but with │
       │          │ component of the    │ escaping undone.       │
       │          │ prefix              │                        │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%L"      │ Log directory root  │ This is either         │
       │          │                     │ /var/log (for the      │
       │          │                     │ system manager) or the │
       │          │                     │ path                   │
       │          │                     │ "$XDG_CONFIG_HOME"     │
       │          │                     │ resolves to with /log  │
       │          │                     │ appended (for user     │
       │          │                     │ managers).             │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%m"      │ Machine ID          │ The machine ID of the  │
       │          │                     │ running system,        │
       │          │                     │ formatted as string.   │
       │          │                     │ See machine-id(5) for  │
       │          │                     │ more information.      │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%o"      │ Operating system ID │ The operating system   │
       │          │                     │ identifier of the      │
       │          │                     │ running system, as     │
       │          │                     │ read from the ID=      │
       │          │                     │ field of               │
       │          │                     │ /etc/os-release. See   │
       │          │                     │ os-release(5) for more │
       │          │                     │ information.           │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%n"      │ Full unit name      │                        │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%N"      │ Full unit name      │ Same as "%n", but with │
       │          │                     │ the type suffix        │
       │          │                     │ removed.               │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%p"      │ Prefix name         │ For instantiated       │
       │          │                     │ units, this refers to  │
       │          │                     │ the string before the  │
       │          │                     │ first "@" character of │
       │          │                     │ the unit name. For     │
       │          │                     │ non-instantiated       │
       │          │                     │ units, same as "%N".   │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%P"      │ Unescaped prefix    │ Same as "%p", but with │
       │          │ name                │ escaping undone.       │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%s"      │ User shell          │ This is the shell of   │
       │          │                     │ the user running the   │
       │          │                     │ service manager        │
       │          │                     │ instance. In case of   │
       │          │                     │ the system manager     │
       │          │                     │ this resolves to       │
       │          │                     │ "/bin/sh".             │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%S"      │ State directory     │ This is either         │
       │          │ root                │ /var/lib (for the      │
       │          │                     │ system manager) or the │
       │          │                     │ path                   │
       │          │                     │ "$XDG_CONFIG_HOME"     │
       │          │                     │ resolves to (for user  │
       │          │                     │ managers).             │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%t"      │ Runtime directory   │ This is either /run/   │
       │          │ root                │ (for the system        │
       │          │                     │ manager) or the path   │
       │          │                     │ "$XDG_RUNTIME_DIR"     │
       │          │                     │ resolves to (for user  │
       │          │                     │ managers).             │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%T"      │ Directory for       │ This is either /tmp or │
       │          │ temporary files     │ the path "$TMPDIR",    │
       │          │                     │ "$TEMP" or "$TMP" are  │
       │          │                     │ set to. (Note that the │
       │          │                     │ directory may be       │
       │          │                     │ specified without a    │
       │          │                     │ trailing slash.)       │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%g"      │ User group          │ This is the name of    │
       │          │                     │ the group running the  │
       │          │                     │ service manager        │
       │          │                     │ instance. In case of   │
       │          │                     │ the system manager     │
       │          │                     │ this resolves to       │
       │          │                     │ "root".                │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%G"      │ User GID            │ This is the numeric    │
       │          │                     │ GID of the user        │
       │          │                     │ running the service    │
       │          │                     │ manager instance. In   │
       │          │                     │ case of the system     │
       │          │                     │ manager this resolves  │
       │          │                     │ to "0".                │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%u"      │ User name           │ This is the name of    │
       │          │                     │ the user running the   │
       │          │                     │ service manager        │
       │          │                     │ instance. In case of   │
       │          │                     │ the system manager     │
       │          │                     │ this resolves to       │
       │          │                     │ "root".                │
       │          │                     │                        │
       │          │                     │ Note that this setting │
       │          │                     │ is not influenced by   │
       │          │                     │ the User= setting      │
       │          │                     │ configurable in the    │
       │          │                     │ [Service] section of   │
       │          │                     │ the service unit.      │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%U"      │ User UID            │ This is the numeric    │
       │          │                     │ UID of the user        │
       │          │                     │ running the service    │
       │          │                     │ manager instance. In   │
       │          │                     │ case of the system     │
       │          │                     │ manager this resolves  │
       │          │                     │ to "0".                │
       │          │                     │                        │
       │          │                     │ Note that this setting │
       │          │                     │ is not influenced by   │
       │          │                     │ the User= setting      │
       │          │                     │ configurable in the    │
       │          │                     │ [Service] section of   │
       │          │                     │ the service unit.      │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%v"      │ Kernel release      │ Identical to uname -r  │
       │          │                     │ output.                │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%V"      │ Directory for       │ This is either         │
       │          │ larger and          │ /var/tmp or the path   │
       │          │ persistent          │ "$TMPDIR", "$TEMP" or  │
       │          │ temporary files     │ "$TMP" are set to.     │
       │          │                     │ (Note that the         │
       │          │                     │ directory may be       │
       │          │                     │ specified without a    │
       │          │                     │ trailing slash.)       │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%w"      │ Operating system    │ The operating system   │
       │          │ version ID          │ version identifier of  │
       │          │                     │ the running system, as │
       │          │                     │ read from the          │
       │          │                     │ VERSION_ID= field of   │
       │          │                     │ /etc/os-release. If    │
       │          │                     │ not set, resolves to   │
       │          │                     │ an empty string. See   │
       │          │                     │ os-release(5) for more │
       │          │                     │ information.           │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%W"      │ Operating system    │ The operating system   │
       │          │ variant ID          │ variant identifier of  │
       │          │                     │ the running system, as │
       │          │                     │ read from the          │
       │          │                     │ VARIANT_ID= field of   │
       │          │                     │ /etc/os-release. If    │
       │          │                     │ not set, resolves to   │
       │          │                     │ an empty string. See   │
       │          │                     │ os-release(5) for more │
       │          │                     │ information.           │
       ├──────────┼─────────────────────┼────────────────────────┤
       │"%%"      │ Single percent sign │ Use "%%" in place of   │
       │          │                     │ "%" to specify a       │
       │          │                     │ single percent sign.   │
       └──────────┴─────────────────────┴────────────────────────┘

EXAMPLES         top

       Example 1. Allowing units to be enabled

       The following snippet (highlighted) allows a unit (e.g.  foo.service)
       to be enabled via systemctl enable:

           [Unit]
           Description=Foo

           [Service]
           ExecStart=/usr/sbin/foo-daemon

           [Install]
           WantedBy=multi-user.target

       After running systemctl enable, a symlink
       /etc/systemd/system/multi-user.target.wants/foo.service linking to
       the actual unit will be created. It tells systemd to pull in the unit
       when starting multi-user.target. The inverse systemctl disable will
       remove that symlink again.

       Example 2. Overriding vendor settings

       There are two methods of overriding vendor settings in unit files:
       copying the unit file from /usr/lib/systemd/system to
       /etc/systemd/system and modifying the chosen settings. Alternatively,
       one can create a directory named unit.d/ within /etc/systemd/system
       and place a drop-in file name.conf there that only changes the
       specific settings one is interested in. Note that multiple such
       drop-in files are read if present, processed in lexicographic order
       of their filename.

       The advantage of the first method is that one easily overrides the
       complete unit, the vendor unit is not parsed at all anymore. It has
       the disadvantage that improvements to the unit file by the vendor are
       not automatically incorporated on updates.

       The advantage of the second method is that one only overrides the
       settings one specifically wants, where updates to the unit by the
       vendor automatically apply. This has the disadvantage that some
       future updates by the vendor might be incompatible with the local
       changes.

       This also applies for user instances of systemd, but with different
       locations for the unit files. See the section on unit load paths for
       further details.

       Suppose there is a vendor-supplied unit
       /usr/lib/systemd/system/httpd.service with the following contents:

           [Unit]
           Description=Some HTTP server
           After=remote-fs.target sqldb.service
           Requires=sqldb.service
           AssertPathExists=/srv/webserver

           [Service]
           Type=notify
           ExecStart=/usr/sbin/some-fancy-httpd-server
           Nice=5

           [Install]
           WantedBy=multi-user.target

       Now one wants to change some settings as an administrator: firstly,
       in the local setup, /srv/webserver might not exist, because the HTTP
       server is configured to use /srv/www instead. Secondly, the local
       configuration makes the HTTP server also depend on a memory cache
       service, memcached.service, that should be pulled in (Requires=) and
       also be ordered appropriately (After=). Thirdly, in order to harden
       the service a bit more, the administrator would like to set the
       PrivateTmp= setting (see systemd.exec(5) for details). And lastly,
       the administrator would like to reset the niceness of the service to
       its default value of 0.

       The first possibility is to copy the unit file to
       /etc/systemd/system/httpd.service and change the chosen settings:

           [Unit]
           Description=Some HTTP server
           After=remote-fs.target sqldb.service memcached.service
           Requires=sqldb.service memcached.service
           AssertPathExists=/srv/www

           [Service]
           Type=notify
           ExecStart=/usr/sbin/some-fancy-httpd-server
           Nice=0
           PrivateTmp=yes

           [Install]
           WantedBy=multi-user.target

       Alternatively, the administrator could create a drop-in file
       /etc/systemd/system/httpd.service.d/local.conf with the following
       contents:

           [Unit]
           After=memcached.service
           Requires=memcached.service
           # Reset all assertions and then re-add the condition we want
           AssertPathExists=
           AssertPathExists=/srv/www

           [Service]
           Nice=0
           PrivateTmp=yes

       Note that for drop-in files, if one wants to remove entries from a
       setting that is parsed as a list (and is not a dependency), such as
       AssertPathExists= (or e.g.  ExecStart= in service units), one needs
       to first clear the list before re-adding all entries except the one
       that is to be removed. Dependencies (After=, etc.) cannot be reset to
       an empty list, so dependencies can only be added in drop-ins. If you
       want to remove dependencies, you have to override the entire unit.

SEE ALSO         top

       systemd(1), systemctl(1), systemd-system.conf(5), systemd.special(7),
       systemd.service(5), systemd.socket(5), systemd.device(5),
       systemd.mount(5), systemd.automount(5), systemd.swap(5),
       systemd.target(5), systemd.path(5), systemd.timer(5),
       systemd.scope(5), systemd.slice(5), systemd.time(7),
       systemd-analyze(1), capabilities(7), systemd.directives(7), uname(1)

NOTES         top

        1. Interface Portability and Stability Promise
           https://systemd.io/PORTABILITY_AND_STABILITY/

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2020-11-01.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-11-01.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or im‐
       provements to the information in this COLOPHON (which is not part of
       the original manual page), send a mail to man-pages@man7.org

systemd 247                                                  SYSTEMD.UNIT(5)

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