+ <para>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.</para>
+
+ <para>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:
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.snapshot</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
+ </para>
+
+ <para>Various settings are allowed to be specified
+ more than once, in which case the interpretation
+ depends on the setting. Often, multiple settings form
+ a list, and setting to an empty value "resets", which
+ means that previous assignments are ignored. When this
+ is allowed, it is mentioned in the description of the
+ setting. Note that using multiple assignments to the
+ same value makes the unit file incompatible with
+ parsers for the XDG <filename>.desktop</filename> file
+ format.</para>
+
+ <para>Unit files are loaded from a set of paths
+ determined during compilation, described in the next section.
+ </para>
+
+ <para>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 <option>X-</option>, 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.</para>
+
+ <para>Boolean arguments used in unit files can be
+ written in various formats. For positive settings the
+ strings <option>1</option>, <option>yes</option>,
+ <option>true</option> and <option>on</option> are
+ equivalent. For negative settings, the strings
+ <option>0</option>, <option>no</option>,
+ <option>false</option> and <option>off</option> are
+ equivalent.</para>
+
+ <para>Time span values encoded in unit files can be
+ written in various formats. A stand-alone number
+ specifies a time in seconds. If suffixed with a time
+ unit, the unit is honored. A concatenation of multiple
+ values with units is supported, in which case the
+ values are added up. Example: "50" refers to 50
+ seconds; "2min 200ms" refers to 2 minutes plus 200
+ milliseconds, i.e. 120200ms. The following time units
+ are understood: s, min, h, d, w, ms, us. For details
+ see
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
+
+ <para>Empty lines and lines starting with # or ; are
+ ignored. This may be used for commenting. Lines ending
+ in a backslash are concatenated with the following
+ line while reading and the backslash is replaced by a
+ space character. This may be used to wrap long lines.</para>
+
+ <para>Along with a unit file
+ <filename>foo.service</filename>, the directory
+ <filename>foo.service.wants/</filename> may exist. All
+ unit files symlinked from such a directory are
+ implicitly added as dependencies of type
+ <varname>Wants=</varname> to the unit. This 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 <varname>Wants=</varname>, see
+ below. The preferred way to create symlinks in the
+ <filename>.wants/</filename> directory of a unit file
+ is with the <command>enable</command> command of the
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ tool which reads information from the [Install]
+ section of unit files (see below). A similar
+ functionality exists for <varname>Requires=</varname>
+ type dependencies as well, the directory suffix is
+ <filename>.requires/</filename> in this case.</para>
+
+ <para>Along with a unit file
+ <filename>foo.service</filename>, a directory
+ <filename>foo.service.d/</filename> may exist. All
+ files with the suffix <literal>.conf</literal> from
+ this directory will be parsed after the file itself is
+ parsed. This is useful to alter or add configuration
+ settings to a unit, without having to modify their
+ unit files. Make sure that the file that is included
+ has the appropriate section headers before any
+ directive. Note that for instanced units this logic
+ will first look for the instance
+ <literal>.d/</literal> subdirectory and read its
+ <literal>.conf</literal> files, followed by the
+ template <literal>.d/</literal> subdirectory and reads
+ its <literal>.conf</literal> files.</para>
+
+ <!-- Note that we do not document .include here, as we
+ consider it mostly obsolete, and want people to
+ use .d/ drop-ins instead. -->
+
+ <para>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.</para>
+
+ <para>Some unit names reflect paths existing in the
+ file system namespace. Example: a device unit
+ <filename>dev-sda.device</filename> refers to a device
+ with the device node <filename noindex='true'>/dev/sda</filename> in
+ the file system namespace. If this applies, a special
+ way to escape the path name is used, so that the
+ result is usable as part of a filename. Basically,
+ given a path, "/" is replaced by "-", and all
+ unprintable characters and the "-" are replaced by
+ C-style "\x2d" escapes. The root directory "/" is
+ encoded as single dash, while otherwise the initial
+ and ending "/" is removed from all paths during
+ transformation. This escaping is reversible.</para>
+
+ <para>Optionally, units may be instantiated from a
+ template file at runtime. 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 <literal>@</literal> character, systemd will look for a
+ unit template that shares the same name but with the
+ instance string (i.e. the part between the <literal>@</literal> character
+ and the suffix) removed. Example: if a service
+ <filename>getty@tty3.service</filename> is requested
+ and no file by that name is found, systemd will look
+ for <filename>getty@.service</filename> and
+ instantiate a service from that configuration file if
+ it is found.</para>
+
+ <para>To refer to the instance string from
+ within the configuration file you may use the special
+ <literal>%i</literal> specifier in many of the
+ configuration options. See below for details.</para>
+
+ <para>If a unit file is empty (i.e. has the file size
+ 0) or is symlinked to <filename>/dev/null</filename>,
+ its configuration will not be loaded and it appears
+ with a load state of <literal>masked</literal>, and
+ cannot be activated. Use this as an effective way to
+ fully disable a unit, making it impossible to start it
+ even manually.</para>
+
+ <para>The unit file format is covered by the
+ <ulink
+ url="http://www.freedesktop.org/wiki/Software/systemd/InterfaceStabilityPromise">Interface
+ Stability Promise</ulink>.</para>
+
+ </refsect1>
+
+ <refsect1>
+ <title>Unit Load Path</title>
+
+ <para>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.</para>
+
+ <para>When systemd is running in user mode
+ (<option>--user</option>) and the variable
+ <varname>$SYSTEMD_UNIT_PATH</varname> is set, this
+ contents of this variable overrides the unit load
+ path. If <varname>$SYSTEMD_UNIT_PATH</varname> ends
+ with an empty component (<literal>:</literal>), the
+ usual unit load path will be appended to the contents
+ of the variable.</para>
+
+ <table>
+ <title>
+ Load path when running in system mode (<option>--system</option>).
+ </title>
+
+ <tgroup cols='2'>
+ <colspec colname='path' />
+ <colspec colname='expl' />
+ <thead>
+ <row>
+ <entry>Path</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry><filename>/etc/systemd/system</filename></entry>
+ <entry>Local configuration</entry>
+ </row>
+ <row>
+ <entry><filename>/run/systemd/system</filename></entry>
+ <entry>Runtime units</entry>
+ </row>
+ <row>
+ <entry><filename>/usr/lib/systemd/system</filename></entry>
+ <entry>Units of installed packages</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <table>
+ <title>
+ Load path when running in user mode (<option>--user</option>).
+ </title>
+
+ <tgroup cols='2'>
+ <colspec colname='path' />
+ <colspec colname='expl' />
+ <thead>
+ <row>
+ <entry>Path</entry>
+ <entry>Description</entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry><filename>$XDG_CONFIG_HOME/systemd/user</filename></entry>
+ <entry>User configuration (only used when $XDG_CONFIG_HOME is set)</entry>
+ </row>
+ <row>
+ <entry><filename>$HOME/.config/systemd/user</filename></entry>
+ <entry>User configuration (only used when $XDG_CONFIG_HOME is not set)</entry>
+ </row>
+ <row>
+ <entry><filename>/etc/systemd/user</filename></entry>
+ <entry>Local configuration</entry>
+ </row>
+ <row>
+ <entry><filename>$XDG_RUNTIME_DIR/systemd/user</filename></entry>
+ <entry>Runtime units (only used when $XDG_RUNTIME_DIR is set)</entry>
+ </row>
+ <row>
+ <entry><filename>/run/systemd/user</filename></entry>
+ <entry>Runtime units</entry>
+ </row>
+ <row>
+ <entry><filename>$XDG_DATA_HOME/systemd/user</filename></entry>
+ <entry>Units of packages that have been installed in the home directory (only used when $XDG_DATA_HOME is set)</entry>
+ </row>
+ <row>
+ <entry><filename>$HOME/.local/share/systemd/user</filename></entry>
+ <entry>Units of packages that have been installed in the home directory (only used when $XDG_DATA_HOME is not set)</entry>
+ </row>
+ <row>
+ <entry><filename>/usr/lib/systemd/user</filename></entry>
+ <entry>Units of packages that have been installed system-wide</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+ <para>Additional units might be loaded into systemd
+ ("linked") from directories not on the unit load
+ path. See the <command>link</command> command for
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>. Also,
+ some units are dynamically created via generators
+ <ulink
+ url="http://www.freedesktop.org/wiki/Software/systemd/Generators/">Generators</ulink>.
+ </para>
+ </refsect1>
+
+ <refsect1>
+ <title>[Unit] Section Options</title>
+
+ <para>Unit file may include a [Unit] section, which
+ carries generic information about the unit that is not
+ dependent on the type of unit:</para>
+
+ <variablelist class='unit-directives'>
+
+ <varlistentry>
+ <term><varname>Description=</varname></term>
+ <listitem><para>A free-form string
+ describing the unit. This is intended
+ for use in UIs to show descriptive
+ information along with the unit
+ name. The description should contain a name
+ that means something to the end user.
+ <literal>Apache2 Web Server</literal> is a good
+ example. Bad examples are
+ <literal>high-performance light-weight HTTP
+ server</literal> (too generic) or
+ <literal>Apache2</literal> (too specific and
+ meaningless for people who do not know
+ Apache).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Documentation=</varname></term>
+ <listitem><para>A space-separated list
+ of URIs referencing documentation for
+ this unit or its
+ configuration. Accepted are only URIs
+ of the types
+ <literal>http://</literal>,
+ <literal>https://</literal>,
+ <literal>file:</literal>,
+ <literal>info:</literal>,
+ <literal>man:</literal>. For more
+ information about the syntax of these
+ URIs, see
+ <citerefentry project='man-pages'><refentrytitle>uri</refentrytitle><manvolnum>7</manvolnum></citerefentry>. 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Requires=</varname></term>
+
+ <listitem><para>Configures requirement
+ dependencies on other units. If this
+ unit gets activated, the units listed
+ here will be activated as well. If one
+ of the other units gets deactivated or
+ its activation fails, this unit will
+ be deactivated. This option may be
+ specified more than once or multiple
+ space-separated units may be specified
+ in one option in which case
+ requirement dependencies for all
+ listed names will be created. Note
+ that requirement dependencies do not
+ influence the order in which services
+ are started or stopped. This has to be
+ configured independently with the
+ <varname>After=</varname> or
+ <varname>Before=</varname> options. If
+ a unit
+ <filename>foo.service</filename>
+ requires a unit
+ <filename>bar.service</filename> as
+ configured with
+ <varname>Requires=</varname> and no
+ ordering is configured with
+ <varname>After=</varname> or
+ <varname>Before=</varname>, then both
+ units will be started simultaneously
+ and without any delay between them if
+ <filename>foo.service</filename> is
+ activated. Often it is a better choice
+ to use <varname>Wants=</varname>
+ instead of
+ <varname>Requires=</varname> in order
+ to achieve a system that is more
+ robust when dealing with failing
+ services.</para>
+
+ <para>Note that dependencies of this
+ type may also be configured outside of
+ the unit configuration file by
+ adding a symlink to a
+ <filename>.requires/</filename> directory
+ accompanying the unit file. For
+ details see above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RequiresOverridable=</varname></term>
+
+ <listitem><para>Similar to
+ <varname>Requires=</varname>.
+ Dependencies listed in
+ <varname>RequiresOverridable=</varname>
+ which cannot be fulfilled or fail to
+ start are ignored if the startup was
+ explicitly requested by the user. If
+ the start-up was pulled in indirectly
+ by some dependency or automatic
+ start-up of units that is not
+ requested by the user, this dependency
+ must be fulfilled and otherwise the
+ transaction fails. Hence, this option
+ may be used to configure dependencies
+ that are normally honored unless the
+ user explicitly starts up the unit, in
+ which case whether they failed or not
+ is irrelevant.</para></listitem>
+
+ </varlistentry>
+ <varlistentry>
+ <term><varname>Requisite=</varname></term>
+ <term><varname>RequisiteOverridable=</varname></term>
+
+ <listitem><para>Similar to
+ <varname>Requires=</varname> and
+ <varname>RequiresOverridable=</varname>,
+ respectively. However, if the units
+ listed here are not started already,
+ they will not be started and the
+ transaction will fail immediately.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Wants=</varname></term>
+
+ <listitem><para>A weaker version of
+ <varname>Requires=</varname>. 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. This is
+ the recommended way to hook start-up
+ of one unit to the start-up of another
+ unit.</para>
+
+ <para>Note that dependencies of this
+ type may also be configured outside of
+ the unit configuration file by adding
+ symlinks to a
+ <filename>.wants/</filename> directory
+ accompanying the unit file. For
+ details, see above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>BindsTo=</varname></term>
+
+ <listitem><para>Configures requirement
+ dependencies, very similar in style to
+ <varname>Requires=</varname>, however
+ in addition to this behavior, it also
+ declares that this unit is stopped
+ when any of the units listed suddenly
+ disappears. Units can suddenly,
+ unexpectedly disappear if a service
+ terminates on its own choice, a device
+ is unplugged or a mount point
+ unmounted without involvement of
+ systemd.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>PartOf=</varname></term>
+
+ <listitem><para>Configures dependencies
+ similar to <varname>Requires=</varname>,
+ 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.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Conflicts=</varname></term>
+
+ <listitem><para>A space-separated list
+ of unit names. Configures negative
+ requirement dependencies. If a unit
+ has a <varname>Conflicts=</varname>
+ setting on another unit, starting the
+ former will stop the latter and vice
+ versa. Note that this setting is
+ independent of and orthogonal to the
+ <varname>After=</varname> and
+ <varname>Before=</varname> ordering
+ dependencies.</para>
+
+ <para>If a unit A that conflicts with
+ a unit B is scheduled to be started at
+ the same time as B, the transaction
+ will either fail (in case both are
+ required part 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 the 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>Before=</varname></term>
+ <term><varname>After=</varname></term>
+
+ <listitem><para>A space-separated list
+ of unit names. Configures ordering
+ dependencies between units. If a unit
+ <filename>foo.service</filename>
+ contains a setting
+ <option>Before=bar.service</option>
+ and both units are being started,
+ <filename>bar.service</filename>'s
+ start-up is delayed until
+ <filename>foo.service</filename> is
+ started up. Note that this setting is
+ independent of and orthogonal to the
+ requirement dependencies as configured
+ by <varname>Requires=</varname>. It is
+ a common pattern to include a unit
+ name in both the
+ <varname>After=</varname> and
+ <varname>Requires=</varname> option, in
+ which case the unit listed will be
+ started before the unit that is
+ configured with these options. This
+ option may be specified more than
+ once, in which case ordering
+ dependencies for all listed names are
+ created. <varname>After=</varname> is
+ the inverse of
+ <varname>Before=</varname>, i.e. while
+ <varname>After=</varname> ensures that
+ the configured unit is started after
+ the listed unit finished starting up,
+ <varname>Before=</varname> ensures the
+ opposite, i.e. that the configured
+ unit is fully started up before the
+ listed unit is started. Note that 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 <varname>After=</varname> on
+ another unit, the former is stopped
+ before the latter if both are shut
+ down. If one unit with an ordering
+ dependency on another unit is shut
+ down while the latter is started up,
+ the shut down is ordered before the
+ start-up regardless of whether the
+ ordering dependency is actually of
+ type <varname>After=</varname> or
+ <varname>Before=</varname>. If two
+ units have no ordering dependencies
+ between them, they are shut down or
+ started up simultaneously, and no
+ ordering takes
+ place. </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>OnFailure=</varname></term>
+
+ <listitem><para>A space-separated list
+ of one or more units that are
+ activated when this unit enters the
+ <literal>failed</literal>
+ state.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>PropagatesReloadTo=</varname></term>
+ <term><varname>ReloadPropagatedFrom=</varname></term>
+
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>JoinsNamespaceOf=</varname></term>
+
+ <listitem><para>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
+ <varname>PrivateNetwork=</varname> and
+ <varname>PrivateTmp=</varname>
+ directives (see
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details). If a unit that has this
+ setting set is started, its processes
+ will see the same
+ <filename>/tmp</filename>,
+ <filename>/tmp/var</filename> 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
+ <varname>PrivateNetwork=</varname>
+ and/or <varname>PrivateTmp=</varname>
+ is enabled for both the unit that
+ joins the namespace and the unit whose
+ namespace is joined.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RequiresMountsFor=</varname></term>
+
+ <listitem><para>Takes a
+ space-separated list of absolute
+ paths. Automatically adds dependencies
+ of type <varname>Requires=</varname>
+ and <varname>After=</varname> for all
+ mount units required to access the
+ specified path.</para>
+
+ <para>Mount points marked with
+ <option>noauto</option> are not
+ mounted automatically and will be
+ ignored for the purposes of this
+ option. If such a mount should be a
+ requirement for this unit,
+ direct dependencies on the mount
+ units may be added
+ (<varname>Requires=</varname> and
+ <varname>After=</varname> or
+ some other combination).
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>OnFailureJobMode=</varname></term>
+
+ <listitem><para>Takes a value of
+ <literal>fail</literal>,
+ <literal>replace</literal>,
+ <literal>replace-irreversibly</literal>,
+ <literal>isolate</literal>,
+ <literal>flush</literal>,
+ <literal>ignore-dependencies</literal>
+ or
+ <literal>ignore-requirements</literal>. Defaults
+ to
+ <literal>replace</literal>. Specifies
+ how the units listed in
+ <varname>OnFailure=</varname> will be
+ enqueued. See
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+ <option>--job-mode=</option> option
+ for details on the possible values. If
+ this is set to
+ <literal>isolate</literal>, only a
+ single unit may be listed in
+ <varname>OnFailure=</varname>..</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>IgnoreOnIsolate=</varname></term>
+
+ <listitem><para>Takes a boolean
+ argument. If <option>true</option>,
+ this unit will not be stopped when
+ isolating another unit. Defaults to
+ <option>false</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>IgnoreOnSnapshot=</varname></term>
+
+ <listitem><para>Takes a boolean
+ argument. If <option>true</option>,
+ this unit will not be included in
+ snapshots. Defaults to
+ <option>true</option> for device and
+ snapshot units, <option>false</option>
+ for the others.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>StopWhenUnneeded=</varname></term>
+
+ <listitem><para>Takes a boolean
+ argument. If <option>true</option>,
+ 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
+ <option>false</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>RefuseManualStart=</varname></term>
+ <term><varname>RefuseManualStop=</varname></term>
+
+ <listitem><para>Takes a boolean
+ argument. If <option>true</option>,
+ 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
+ <option>false</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>AllowIsolate=</varname></term>
+
+ <listitem><para>Takes a boolean
+ argument. If <option>true</option>,
+ this unit may be used with the
+ <command>systemctl isolate</command>
+ 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
+ <option>false</option>.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>DefaultDependencies=</varname></term>
+
+ <listitem><para>Takes a boolean
+ argument. If <option>true</option>,
+ (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 <option>false</option>. It is
+ highly recommended to leave this
+ option enabled for the majority of
+ common units. If set to
+ <option>false</option>, this option
+ does not disable all implicit
+ dependencies, just non-essential
+ ones.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>JobTimeoutSec=</varname></term>
+ <term><varname>JobTimeoutAction=</varname></term>
+ <term><varname>JobTimeoutRebootArgument=</varname></term>
+
+ <listitem><para>When a job for this
+ unit is queued a time-out may be
+ configured. If this time limit is
+ reached, the job will be cancelled,
+ the unit however will not change state
+ or even enter the
+ <literal>failed</literal> mode. This
+ value defaults to 0 (job timeouts
+ disabled), except for device
+ units. NB: this timeout is independent
+ from any unit-specific timeout (for
+ example, the timeout set with
+ <varname>StartTimeoutSec=</varname> 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.</para>
+
+ <para><varname>JobTimeoutAction=</varname>
+ optionally configures an additional
+ action to take when the time-out is
+ hit. It takes the same values as the
+ per-service
+ <varname>StartLimitAction=</varname>
+ setting, see
+ <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details. Defaults to
+ <option>none</option>. <varname>JobTimeoutRebootArgument=</varname>
+ configures an optional reboot string
+ to pass to the
+ <citerefentry><refentrytitle>reboot</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ system call.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>ConditionArchitecture=</varname></term>
+ <term><varname>ConditionVirtualization=</varname></term>
+ <term><varname>ConditionHost=</varname></term>
+ <term><varname>ConditionKernelCommandLine=</varname></term>
+ <term><varname>ConditionSecurity=</varname></term>
+ <term><varname>ConditionCapability=</varname></term>
+ <term><varname>ConditionACPower=</varname></term>
+ <term><varname>ConditionNeedsUpdate=</varname></term>
+ <term><varname>ConditionFirstBoot=</varname></term>
+ <term><varname>ConditionPathExists=</varname></term>
+ <term><varname>ConditionPathExistsGlob=</varname></term>
+ <term><varname>ConditionPathIsDirectory=</varname></term>
+ <term><varname>ConditionPathIsSymbolicLink=</varname></term>
+ <term><varname>ConditionPathIsMountPoint=</varname></term>
+ <term><varname>ConditionPathIsReadWrite=</varname></term>
+ <term><varname>ConditionDirectoryNotEmpty=</varname></term>
+ <term><varname>ConditionFileNotEmpty=</varname></term>
+ <term><varname>ConditionFileIsExecutable=</varname></term>
+
+ <!-- We don't document ConditionNull=
+ here as it is not particularly
+ useful and probably just
+ confusing. -->
+
+ <listitem><para>Before starting a unit
+ verify that the specified condition is
+ true. If it is not true, the starting
+ of the unit will be skipped, however
+ all ordering dependencies of it are
+ still respected. A failing condition
+ will not result in the unit being
+ moved into a failure state. The
+ condition is checked at the time the
+ queued start job is to be
+ executed.</para>
+
+ <para><varname>ConditionArchitecture=</varname>
+ may be used to check whether the
+ system is running on a specific
+ architecture. Takes one of
+ <varname>x86</varname>,
+ <varname>x86-64</varname>,
+ <varname>ppc</varname>,
+ <varname>ppc-le</varname>,
+ <varname>ppc64</varname>,
+ <varname>ppc64-le</varname>,
+ <varname>ia64</varname>,
+ <varname>parisc</varname>,
+ <varname>parisc64</varname>,
+ <varname>s390</varname>,
+ <varname>s390x</varname>,
+ <varname>sparc</varname>,
+ <varname>sparc64</varname>,
+ <varname>mips</varname>,
+ <varname>mips-le</varname>,
+ <varname>mips64</varname>,
+ <varname>mips64-le</varname>,
+ <varname>alpha</varname>,
+ <varname>arm</varname>,
+ <varname>arm-be</varname>,
+ <varname>arm64</varname>,
+ <varname>arm64-be</varname>,
+ <varname>sh</varname>,
+ <varname>sh64</varname>,
+ <varname>m86k</varname>,
+ <varname>tilegx</varname>,
+ <varname>cris</varname> to test
+ against a specific architecture. The
+ architecture is determined from the
+ information returned by
+ <citerefentry><refentrytitle>uname</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ and is thus subject to
+ <citerefentry><refentrytitle>personality</refentrytitle><manvolnum>2</manvolnum></citerefentry>. Note
+ that a <varname>Personality=</varname>
+ setting in the same unit file has no
+ effect on this condition. A special
+ architecture name
+ <varname>native</varname> is mapped to
+ the architecture the system manager
+ itself is compiled for. The test may
+ be negated by prepending an
+ exclamation mark.</para>
+
+ <para><varname>ConditionVirtualization=</varname>
+ may be used to 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
+ <varname>vm</varname> and
+ <varname>container</varname> to test
+ against a generic type of
+ virtualization solution, or one of
+ <varname>qemu</varname>,
+ <varname>kvm</varname>,
+ <varname>zvm</varname>,
+ <varname>vmware</varname>,
+ <varname>microsoft</varname>,
+ <varname>oracle</varname>,
+ <varname>xen</varname>,
+ <varname>bochs</varname>,
+ <varname>uml</varname>,
+ <varname>openvz</varname>,
+ <varname>lxc</varname>,
+ <varname>lxc-libvirt</varname>,
+ <varname>systemd-nspawn</varname>,
+ <varname>docker</varname> to test
+ against a specific implementation. See
+ <citerefentry><refentrytitle>systemd-detect-virt</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ 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.</para>
+
+ <para><varname>ConditionHost=</varname>
+ 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
+ <citerefentry><refentrytitle>gethostname</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
+ or a machine ID formatted as string
+ (see
+ <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
+ The test may be negated by prepending
+ an exclamation mark.</para>
+
+ <para><varname>ConditionKernelCommandLine=</varname>
+ 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
+ <literal>=</literal>). 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.</para>
+
+ <para><varname>ConditionSecurity=</varname>
+ may be used to check whether the given
+ security module is enabled on the
+ system. Currently the recognized
+ values values are
+ <varname>selinux</varname>,
+ <varname>apparmor</varname>,
+ <varname>ima</varname>,
+ <varname>smack</varname> and
+ <varname>audit</varname>. The test may
+ be negated by prepending an
+ exclamation mark.</para>
+
+ <para><varname>ConditionCapability=</varname>
+ may be used to 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
+ <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ for details). Pass a capability name
+ such as <literal>CAP_MKNOD</literal>,
+ possibly prefixed with an exclamation
+ mark to negate the check.</para>
+
+ <para><varname>ConditionACPower=</varname>
+ may be used to 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
+ <varname>true</varname>, 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 <varname>false</varname>, the
+ condition will hold only if there is
+ at least one AC connector known and
+ all AC connectors are disconnected
+ from a power source.</para>
+
+ <para><varname>ConditionNeedsUpdate=</varname>
+ takes one of <filename>/var</filename>
+ or <filename>/etc</filename> as
+ argument, possibly prefixed with a
+ <literal>!</literal> (for inverting
+ the condition). This condition may be
+ used to conditionalize units on
+ whether the specified directory
+ requires an update because
+ <filename>/usr</filename>'s
+ modification time is newer than the
+ stamp file
+ <filename>.updated</filename> in the
+ specified directory. This is useful to
+ implement offline updates of the
+ vendor operating system resources in
+ <filename>/usr</filename> that require
+ updating of <filename>/etc</filename>
+ or <filename>/var</filename> on the
+ next following boot. Units making use
+ of this condition should order
+ themselves before
+ <citerefentry><refentrytitle>systemd-update-done.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ to make sure they run before the stamp
+ files's modification time gets reset
+ indicating a completed update.</para>
+
+ <para><varname>ConditionFirstBoot=</varname>
+ takes a boolean argument. This
+ condition may be used to
+ conditionalize units on whether the
+ system is booting up with an
+ unpopulated <filename>/etc</filename>
+ directory. This may be used to
+ populate <filename>/etc</filename> on
+ the first boot after factory reset, or
+ when a new system instances boots up
+ for the first time.</para>
+
+ <para>With
+ <varname>ConditionPathExists=</varname>
+ a file existence condition is
+ checked before a unit is started. If
+ the specified absolute path name does
+ not exist, the condition will
+ fail. If the absolute path name passed
+ to
+ <varname>ConditionPathExists=</varname>
+ is prefixed with an exclamation mark
+ (<literal>!</literal>), the test is negated, and the unit
+ is only started if the path does not
+ exist.</para>
+
+ <para><varname>ConditionPathExistsGlob=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>,
+ but checks for the existence of at
+ least one file or directory matching
+ the specified globbing pattern.</para>
+
+ <para><varname>ConditionPathIsDirectory=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and is a
+ directory.</para>
+
+ <para><varname>ConditionPathIsSymbolicLink=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and is a symbolic
+ link.</para>
+
+ <para><varname>ConditionPathIsMountPoint=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and is a mount
+ point.</para>
+
+ <para><varname>ConditionPathIsReadWrite=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether the underlying
+ file system is readable and writable
+ (i.e. not mounted
+ read-only).</para>
+
+ <para><varname>ConditionDirectoryNotEmpty=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and is a non-empty
+ directory.</para>
+
+ <para><varname>ConditionFileNotEmpty=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists and refers to a regular file
+ with a non-zero size.</para>
+
+ <para><varname>ConditionFileIsExecutable=</varname>
+ is similar to
+ <varname>ConditionPathExists=</varname>
+ but verifies whether a certain path
+ exists, is a regular file and marked
+ executable.</para>
+
+ <para>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 be
+ prefixed with a pipe symbol (|) in
+ which case a 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. Except for
+ <varname>ConditionPathIsSymbolicLink=</varname>,
+ all path checks follow symlinks. 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>AssertArchitecture=</varname></term>
+ <term><varname>AssertVirtualization=</varname></term>
+ <term><varname>AssertHost=</varname></term>
+ <term><varname>AssertKernelCommandLine=</varname></term>
+ <term><varname>AssertSecurity=</varname></term>
+ <term><varname>AssertCapability=</varname></term>
+ <term><varname>AssertACPower=</varname></term>
+ <term><varname>AssertNeedsUpdate=</varname></term>
+ <term><varname>AssertFirstBoot=</varname></term>
+ <term><varname>AssertPathExists=</varname></term>
+ <term><varname>AssertPathExistsGlob=</varname></term>
+ <term><varname>AssertPathIsDirectory=</varname></term>
+ <term><varname>AssertPathIsSymbolicLink=</varname></term>
+ <term><varname>AssertPathIsMountPoint=</varname></term>
+ <term><varname>AssertPathIsReadWrite=</varname></term>
+ <term><varname>AssertDirectoryNotEmpty=</varname></term>
+ <term><varname>AssertFileNotEmpty=</varname></term>
+ <term><varname>AssertFileIsExecutable=</varname></term>
+
+ <listitem><para>Similar to the
+ <varname>ConditionArchitecture=</varname>,
+ <varname>ConditionVirtualization=</varname>,
+ ... 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 it was triggered by.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>SourcePath=</varname></term>
+ <listitem><para>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.</para></listitem>
+ </varlistentry>
+ </variablelist>
+