path: root/man/systemd.special.xml

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<refentry id="systemd.special">

        <refentryinfo>
                <title>systemd.special</title>
                <productname>systemd</productname>

                <authorgroup>
                        <author>
                                <contrib>Developer</contrib>
                                <firstname>Lennart</firstname>
                                <surname>Poettering</surname>
                                <email>lennart@poettering.net</email>
                        </author>
                </authorgroup>
        </refentryinfo>

        <refmeta>
                <refentrytitle>systemd.special</refentrytitle>
                <manvolnum>7</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>systemd.special</refname>
                <refpurpose>Special systemd units</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <para><filename>basic.target</filename>,
                <filename>bluetooth.target</filename>,
                <filename>ctrl-alt-del.target</filename>,
                <filename>cryptsetup.target</filename>,
                <filename>dbus.service</filename>,
                <filename>dbus.socket</filename>,
                <filename>default.target</filename>,
                <filename>display-manager.service</filename>,
                <filename>emergency.target</filename>,
                <filename>exit.target</filename>,
                <filename>final.target</filename>,
                <filename>getty.target</filename>,
                <filename>graphical.target</filename>,
                <filename>halt.target</filename>,
                <filename>hibernate.target</filename>,
                <filename>hybrid-sleep.target</filename>,
                <filename>initrd-fs.target</filename>,
                <filename>kbrequest.target</filename>,
                <filename>kexec.target</filename>,
                <filename>local-fs.target</filename>,
                <filename>local-fs-pre.target</filename>,
                <filename>multi-user.target</filename>,
                <filename>network.target</filename>,
                <filename>nss-lookup.target</filename>,
                <filename>nss-user-lookup.target</filename>,
                <filename>paths.target</filename>,
                <filename>poweroff.target</filename>,
                <filename>printer.target</filename>,
                <filename>reboot.target</filename>,
                <filename>remote-fs.target</filename>,
                <filename>remote-fs-pre.target</filename>,
                <filename>rescue.target</filename>,
                <filename>initrd-root-fs.target</filename>,
                <filename>rpcbind.target</filename>,
                <filename>runlevel2.target</filename>,
                <filename>runlevel3.target</filename>,
                <filename>runlevel4.target</filename>,
                <filename>runlevel5.target</filename>,
                <filename>shutdown.target</filename>,
                <filename>sigpwr.target</filename>,
                <filename>sleep.target</filename>,
                <filename>smartcard.target</filename>,
                <filename>sockets.target</filename>,
                <filename>sound.target</filename>,
                <filename>suspend.target</filename>,
                <filename>swap.target</filename>,
                <filename>sysinit.target</filename>,
                <filename>syslog.socket</filename>,
                <filename>system-update.target</filename>,
                <filename>time-sync.target</filename>,
                <filename>timers.target</filename>,
                <filename>umount.target</filename></para>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para>A few units are treated specially by
                systemd. They have special internal semantics and
                cannot be renamed.</para>
        </refsect1>

        <refsect1>
                <title>Special System Units</title>

                <variablelist>
                        <varlistentry>
                                <term><filename>basic.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        covering basic boot-up.</para>
                                        <para>systemd automatically
                                        adds dependencies of the types
                                        <varname>Requires=</varname>
                                        and <varname>After=</varname>
                                        for this target unit to all
                                        services (except for those
                                        with
                                        <varname>DefaultDependencies=no</varname>).</para>

                                        <para>Usually this should
                                        pull-in all mount points, swap
                                        devices, sockets, timers, and
                                        path units and other basic
                                        initialization necessary for
                                        general purpose
                                        daemons.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>bluetooth.target</filename></term>
                                <listitem>
                                        <para>This target is started
                                        automatically as soon as a
                                        Bluetooth controller is
                                        plugged in or becomes
                                        available at boot.</para>

                                        <para>This may be used to pull
                                        in Bluetooth management
                                        daemons dynamically when
                                        Bluetooth hardware is
                                        found.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>ctrl-alt-del.target</filename></term>
                                <listitem>
                                        <para>systemd starts this
                                        target whenever
                                        Control+Alt+Del is pressed on
                                        the console. Usually this
                                        should be aliased (symlinked)
                                        to
                                        <filename>reboot.target</filename>.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>cryptsetup.target</filename></term>
                                <listitem>
                                        <para>A target that pulls in
                                        setup services for all
                                        encrypted block
                                        devices.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>dbus.service</filename></term>
                                <listitem>
                                        <para>A special unit for the
                                        D-Bus bus daemon. As soon as
                                        this service is fully started
                                        up systemd will connect to it
                                        and register its
                                        service.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>dbus.socket</filename></term>
                                <listitem>
                                        <para>A special unit for the
                                        D-Bus system bus socket. All
                                        units with
                                        <varname>Type=dbus</varname>
                                        automatically gain a
                                        dependency on this
                                        unit.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>default.target</filename></term>
                                <listitem>
                                        <para>The default unit systemd
                                        starts at bootup. Usually this
                                        should be aliased (symlinked)
                                        to
                                        <filename>multi-user.target</filename>
                                        or
                                        <filename>graphical.target</filename>.</para>

                                        <para>The default unit systemd
                                        starts at bootup can be
                                        overridden with the
                                        <varname>systemd.unit=</varname>
                                        kernel command line option.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>display-manager.service</filename></term>
                                <listitem>
                                        <para>The display manager
                                        service. Usually this should
                                        be aliased (symlinked) to
                                        <filename>gdm.service</filename>
                                        or a similar display manager
                                        service.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>emergency.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that starts an emergency
                                        shell on the main
                                        console. This unit is supposed
                                        to be used with the kernel
                                        command line option
                                        <varname>systemd.unit=</varname>
                                        and has otherwise little use.
                                        </para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>final.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that is used during the
                                        shutdown logic and may be used
                                        to pull in late services after
                                        all normal services are
                                        already terminated and all
                                        mounts unmounted.
                                        </para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>getty.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that pulls in statically
                                        configured local TTY
                                        <filename>getty</filename>
                                        instances.
                                        </para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>graphical.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for setting up a graphical
                                        login screen. This pulls in
                                        <filename>multi-user.target</filename>.</para>

                                        <para>Units that are needed
                                        for graphical logins shall add
                                        <varname>Wants=</varname>
                                        dependencies for their unit to
                                        this unit (or
                                        <filename>multi-user.target</filename>)
                                        during installation. This is
                                        best configured via
                                        <varname>WantedBy=graphical.target</varname>
                                        in the unit's
                                        <literal>[Install]</literal>
                                        section.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>hibernate.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for hibernating the
                                        system. This pulls in
                                        <filename>sleep.target</filename>.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>hybrid-sleep.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for hibernating and suspending the
                                        system at the same time. This pulls in
                                        <filename>sleep.target</filename>.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>halt.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for shutting down and halting
                                        the system. Note that this
                                        target is distinct from
                                        <filename>poweroff.target</filename>
                                        in that it generally really
                                        just halts the system rather
                                        than powering it down.</para>

                                        <para>Applications wanting to
                                        halt the system should start
                                        this unit.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>initrd-fs.target</filename></term>
                                <listitem>
                                        <para><citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                        automatically adds
                                        dependencies of type
                                        <varname>Before=</varname> to
                                        <filename>sysroot-usr.mount</filename>
                                        and all mount points fround in
                                        <filename>/etc/fstab</filename>
                                        that have the
                                        <option>auto</option> and
                                        <option>x-initrd.mount</option>
                                        mount options set.
                                        </para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>kbrequest.target</filename></term>
                                <listitem>
                                        <para>systemd starts this
                                        target whenever Alt+ArrowUp is
                                        pressed on the console. This
                                        is a good candidate to be
                                        aliased (symlinked) to
                                        <filename>rescue.target</filename>.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>kexec.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for shutting down and rebooting the system via kexec.</para>

                                        <para>Applications wanting to
                                        reboot the system with kexec should start
                                        this unit.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>local-fs.target</filename></term>
                                <listitem>
                                        <para><citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                        automatically adds
                                        dependencies of type
                                        <varname>Before=</varname> to
                                        all mount units that refer to
                                        local mount points for this
                                        target unit. In addition, it
                                        adds dependencies of type
                                        <varname>Wants=</varname> to
                                        this target unit for those
                                        mounts listed in
                                        <filename>/etc/fstab</filename>
                                        that have the
                                        <option>auto</option> mount
                                        option set.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>local-fs-pre.target</filename></term>
                                <listitem>
                                        <para>This target unit is
                                        automatically ordered before
                                        all local mount points marked
                                        with <option>auto</option>
                                        (see above). It can be used to
                                        execute certain units before
                                        all local mounts.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>multi-user.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for setting up a multi-user
                                        system (non-graphical). This
                                        is pulled in by
                                        <filename>graphical.target</filename>.</para>

                                        <para>Units that are needed
                                        for a multi-user system shall
                                        add <varname>Wants=</varname>
                                        dependencies for their unit to
                                        this unit during
                                        installation. This is best
                                        configured via
                                        <varname>WantedBy=multi-uer.target</varname>
                                        in the unit's
                                        <literal>[Install]</literal>
                                        section.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>network.target</filename></term>
                                <listitem>
                                        <para>systemd automatically
                                        adds dependencies of type
                                        <varname>After=</varname> for
                                        this target unit to all SysV
                                        init script service units with
                                        an LSB header referring to the
                                        <literal>$network</literal>
                                        facility.</para>

                                        <para>This unit is supposed to
                                        indicate when the network is
                                        "up", but it is only very
                                        loosely defined what that is
                                        supposed to mean. Also see <ulink
                                        url="http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget">Running
                                        Services After the Network is
                                        up</ulink> for more
                                        information.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>nss-lookup.target</filename></term>
                                <listitem>
                                        <para>A target that should be
                                        used as synchronization point
                                        for all host/network name
                                        service lookups. Note that
                                        this is independent of
                                        user/group name lookups for
                                        which
                                        <filename>nss-user-lookup.target</filename>
                                        should be used. systemd
                                        automatically adds
                                        dependencies of type
                                        <varname>After=</varname> for
                                        this target unit to all SysV
                                        init script service units with
                                        an LSB header referring to the
                                        <literal>$named</literal>
                                        facility.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>nss-user-lookup.target</filename></term>
                                <listitem>
                                        <para>A target that should be
                                        used as synchronization point
                                        for all user/group name
                                        service lookups. Note that
                                        this is independent of
                                        host/network name lookups for
                                        which
                                        <filename>nss-lookup.target</filename>
                                        should be used. </para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>paths.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that sets up all path units
                                        (see
                                        <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                                        for details) that shall be
                                        active after boot.</para>

                                        <para>It is recommended that
                                        path units installed by
                                        applications get pulled in via
                                        <varname>Wants=</varname>
                                        dependencies from this
                                        unit. This is best configured
                                        via a
                                        <varname>WantedBy=paths.target</varname>
                                        in the path unit's
                                        <literal>[Install]</literal>
                                        section.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>poweroff.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for shutting down and powering off the system.</para>

                                        <para>Applications wanting to
                                        power off the system should start
                                        this unit.</para>

                                        <para><filename>runlevel0.target</filename>
                                        is an alias for this target
                                        unit, for compatibility with SysV.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>printer.target</filename></term>
                                <listitem>
                                        <para>This target is started
                                        automatically as soon as a
                                        printer is plugged in or
                                        becomes available at
                                        boot.</para>

                                        <para>This may be used to pull
                                        in printer management
                                        daemons dynamically when
                                        printer hardware is
                                        found.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>reboot.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for shutting down and rebooting the system.</para>

                                        <para>Applications wanting to
                                        reboot the system should start
                                        this unit.</para>

                                        <para><filename>runlevel6.target</filename>
                                        is an alias for this target
                                        unit, for compatibility with SysV.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>remote-fs.target</filename></term>
                                <listitem>
                                        <para>Similar to
                                        <filename>local-fs.target</filename>,
                                        but for remote mount
                                        points.</para>

                                        <para>systemd automatically
                                        adds dependencies of type
                                        <varname>After=</varname> for
                                        this target unit to all SysV
                                        init script service units with
                                        an LSB header referring to the
                                        <literal>$remote_fs</literal>
                                        facility.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>remote-fs-pre.target</filename></term>
                                <listitem>
                                        <para>This target unit is
                                        automatically ordered before
                                        all remote mount points marked
                                        with <option>auto</option>
                                        (see above). It can be used to
                                        execute certain units before
                                        all remote mounts.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>rescue.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for setting up the base system
                                        and a rescue shell.</para>

                                        <para><filename>runlevel1.target</filename>
                                        is an alias for this target
                                        unit, for compatibility with SysV.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>initrd-root-fs.target</filename></term>
                                <listitem>
                                        <para><citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                        automatically adds
                                        dependencies of type
                                        <varname>Before=</varname> to
                                        the
                                        <filename>sysroot.mount</filename>
                                        unit, which is generated from
                                        the kernel command line.
                                        </para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>rpcbind.target</filename></term>
                                <listitem>
                                        <para>systemd automatically
                                        adds dependencies of type
                                        <varname>After=</varname> for
                                        this target unit to all SysV
                                        init script service units with
                                        an LSB header referring to the
                                        <literal>$portmap</literal>
                                        facility.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>runlevel2.target</filename></term>
                                <term><filename>runlevel3.target</filename></term>
                                <term><filename>runlevel4.target</filename></term>
                                <term><filename>runlevel5.target</filename></term>
                                <listitem>
                                        <para>These are targets that
                                        are called whenever the SysV
                                        compatibility code asks for
                                        runlevel 2, 3, 4, 5,
                                        respectively. It is a good
                                        idea to make this an alias for
                                        (i.e. symlink to)
                                        <filename>multi-user.target</filename>
                                        (for runlevel 2) or
                                        <filename>graphical.target</filename>
                                        (the others).</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>shutdown.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that terminates the services
                                        on system shutdown.</para>

                                        <para>Services that shall be
                                        terminated on system shutdown
                                        shall add <varname>Conflicts=</varname>
                                        dependencies to this unit for
                                        their service unit, which is
                                        implicitly done when
                                        <varname>DefaultDependencies=yes</varname>
                                        is set (the default).</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>sigpwr.target</filename></term>
                                <listitem>
                                        <para>A special target that is
                                        started when systemd receives
                                        the SIGPWR process signal,
                                        which is normally sent by the
                                        kernel or UPS daemons when
                                        power fails.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>sleep.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that is pulled in by
                                        <filename>suspend.target</filename>,
                                        <filename>hibernate.target</filename>
                                        and
                                        <filename>hybrid-sleep.target</filename>
                                        and may be used to hook units
                                        into the sleep state
                                        logic.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>smartcard.target</filename></term>
                                <listitem>
                                        <para>This target is started
                                        automatically as soon as a
                                        smartcard controller is
                                        plugged in or becomes
                                        available at boot.</para>

                                        <para>This may be used to pull
                                        in printer management
                                        daemons dynamically when
                                        smartcard hardware is
                                        found.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>sockets.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that sets up all socket
                                        units.(see
                                        <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                                        for details) that shall be
                                        active after boot.</para>

                                        <para>Services that can be
                                        socket-activated shall add
                                        <varname>Wants=</varname>
                                        dependencies to this unit for
                                        their socket unit during
                                        installation. This is best
                                        configured via a
                                        <varname>WantedBy=sockets.target</varname>
                                        in the socket unit's
                                        <literal>[Install]</literal>
                                        section.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>sound.target</filename></term>
                                <listitem>
                                        <para>This target is started
                                        automatically as soon as a
                                        sound card is plugged in or
                                        becomes available at
                                        boot.</para>

                                        <para>This may be used to pull
                                        in audio management daemons
                                        dynamically when printer
                                        hardware is found.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>suspend.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        for suspending the
                                        system. This pulls in
                                        <filename>sleep.target</filename>.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>swap.target</filename></term>
                                <listitem>
                                        <para>Similar to
                                        <filename>local-fs.target</filename>, but for swap
                                        partitions and swap
                                        files.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>sysinit.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        covering early boot-up scripts.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>syslog.socket</filename></term>
                                <listitem>
                                        <para>The socket unit
                                        syslog implementations should
                                        listen on. All userspace log
                                        messages will be made
                                        available on this socket. For
                                        more information about syslog
                                        integration, please consult
                                        the <ulink
                                        url="http://www.freedesktop.org/wiki/Software/systemd/syslog">Syslog
                                        Interface</ulink>
                                        document.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>system-update.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that is used for off-line
                                        system updates.
                                        <citerefentry><refentrytitle>systemd-system-update-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
                                        will redirect the boot process
                                        to this target if
                                        <filename>/system-update</filename>
                                        exists. For more information
                                        see the <ulink
                                        url="http://freedesktop.org/wiki/Software/systemd/SystemUpdates">System
                                        Updates
                                        Specification</ulink>.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>time-sync.target</filename></term>
                                <listitem>
                                        <para>systemd automatically
                                        adds dependencies of type
                                        <varname>After=</varname> for
                                        this target unit to all SysV
                                        init script service units with
                                        an LSB header referring to the
                                        <literal>$time</literal>
                                        facility.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>timers.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that sets up all timer
                                        units (see
                                        <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                                        for details) that shall be
                                        active after boot.</para>

                                        <para>It is recommended that
                                        timer units installed by
                                        applications get pulled in via
                                        <varname>Wants=</varname>
                                        dependencies from this
                                        unit. This is best configured
                                        via
                                        <varname>WantedBy=timers.target</varname>
                                        in the timer unit's
                                        <literal>[Install]</literal>
                                        section.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><filename>umount.target</filename></term>
                                <listitem>
                                        <para>A special target unit
                                        that umounts all mount and
                                        automount points on system
                                        shutdown.</para>

                                        <para>Mounts that shall be
                                        unmounted on system shutdown
                                        shall add Conflicts
                                        dependencies to this unit for
                                        their mount unit, which is
                                        implicitly done when
                                        <varname>DefaultDependencies=yes</varname>
                                        is set (the default).</para>
                                </listitem>
                        </varlistentry>

                </variablelist>
        </refsect1>

        <refsect1>
                <title>Special User Units</title>

                <para>When systemd runs as a user instance, the
                following special units are available, which have
                similar definitions as their system counterparts:
                <filename>default.target</filename>,
                <filename>shutdown.target</filename>,
                <filename>sockets.target</filename></para>

                <para>In addition the following special unit is
                understood only when systemd runs as service instance:</para>

                <variablelist>
                        <varlistentry>
                                <term><filename>exit.target</filename></term>
                                <listitem>
                                        <para>A special service unit
                                        for shutting down the
                                        user service manager.</para>

                                        <para>Applications wanting to
                                        terminate the user service
                                        manager should start this
                                        unit. If systemd receives
                                        SIGTERM or SIGINT when running
                                        as user service daemon it will
                                        start this unit.</para>

                                        <para>Normally, this pulls in
                                        <filename>shutdown.target</filename>
                                        which in turn should be
                                        conflicted by all units that
                                        want to be shut down on
                                        user service manager exit.</para>
                                </listitem>
                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                  <title>See Also</title>
                  <para>
                          <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
                  </para>
        </refsect1>

</refentry>