+++ /dev/null
-<?xml version='1.0'?> <!--*-nxml-*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
- "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-
-<!--
- This file is part of systemd.
-
- Copyright 2010 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
--->
-
-<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>cryptsetup-pre.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>network-online.target</filename>,
- <filename>network-pre.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>,
- <filename>-.slice</filename>,
- <filename>system.slice</filename>,
- <filename>user.slice</filename>,
- <filename>machine.slice</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>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
- found in <filename>/etc/fstab</filename> that have
- <option>x-initrd.mount</option> and not have
- <option>noauto</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>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-user.target</varname> in the unit's
- <literal>[Install]</literal> section.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><filename>network-online.target</filename></term>
- <listitem>
- <para>Units that strictly require a configured network
- connection should pull in
- <filename>network-online.target</filename> (via a
- <varname>Wants=</varname> type dependency) and order
- themselves after it. This target unit is intended to pull in
- a service that delays further execution until the network is
- sufficiently set up. What precisely this requires is left to
- the implementation of the network managing service.</para>
-
- <para>Note the distinction between this unit and
- <filename>network.target</filename>. This unit is an active
- unit (i.e. pulled in by the consumer rather than the
- provider of this functionality) and pulls in a service which
- possibly adds substantial delays to further execution. In
- contrast, <filename>network.target</filename> is a passive
- unit (i.e. pulled in by the provider of the functionality,
- rather than the consumer) that usually does not delay
- execution much. Usually, <filename>network.target</filename>
- is part of the boot of most systems, while
- <filename>network-online.target</filename> is not, except
- when at least one unit requires it. Also see <ulink
- url="http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget">Running
- Services After the Network is up</ulink> for more
- information.</para>
-
- <para>All mount units for remote network file systems
- automatically pull in this unit, and order themselves after
- it. Note that networking daemons that simply provide
- functionality to other hosts generally do not need to pull
- this in.</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>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>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>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>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>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>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 System Units for Devices</title>
-
- <para>Some target units are automatically pulled in as devices of
- certain kinds show up in the system. These may be used to
- automatically activate various services based on the specific type
- of the available hardware.</para>
-
- <variablelist>
- <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>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>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 smartcard management
- daemons dynamically when smartcard hardware is found.</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 audio hardware is found.</para>
- </listitem>
- </varlistentry>
- </variablelist>
- </refsect1>
-
- <refsect1>
- <title>Special Passive System Units </title>
-
- <para>A number of special system targets are defined that can be
- used to properly order boot-up of optional services. These targets
- are generally not part of the initial boot transaction, unless
- they are explicitly pulled in by one of the implementing services.
- Note specifically that these <emphasis>passive</emphasis> target
- units are generally not pulled in by the consumer of a service,
- but by the provider of the service. This means: a consuming
- service should order itself after these targets (as appropriate),
- but not pull it in. A providing service should order itself before
- these targets (as appropriate) and pull it in (via a
- <varname>Wants=</varname> type dependency).</para>
-
- <para>Note that these passive units cannot be started manually,
- i.e. <literal>systemctl start time-sync.target</literal> will fail
- with an error. They can only be pulled in by dependency. This is
- enforced since they exist for ordering purposes only and thus are
- not useful as only unit within a transaction.</para>
-
- <variablelist>
- <varlistentry>
- <term><filename>cryptsetup-pre.target</filename></term>
- <listitem>
- <para>This passive target unit may be pulled in by services
- that want to run before any encrypted block device is set
- up. All encrypted block devices are set up after this target
- has been reached. Since the shutdown order is implicitly the
- reverse start-up order between units, this target is
- particularly useful to ensure that a service is shut down
- only after all encrypted block devices are fully
- stopped.</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>network.target</filename></term>
- <listitem>
- <para>This unit is supposed to indicate when network
- functionality is available, but it is only very weakly
- defined what that is supposed to mean, with one exception:
- at shutdown, a unit that is ordered after
- <filename>network.target</filename> will be stopped before
- the network -- to whatever level it might be set up then --
- is shut down. It is hence useful when writing service files
- that require network access on shutdown, which should order
- themselves after this target, but not pull it in. Also see
- <ulink url="http://www.freedesktop.org/wiki/Software/systemd/NetworkTarget">Running
- Services After the Network is up</ulink> for more
- information. Also see
- <filename>network-online.target</filename> described
- above.</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>$network</literal> facility.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><filename>network-pre.target</filename></term>
- <listitem>
- <para>This passive target unit may be pulled in by services
- that want to run before any network is set up, for example
- for the purpose of setting up a firewall. All network
- management software orders itself after this target, but
- does not pull it in.</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.
- All services for which the availability of full host/network
- name resolution is essential should be ordered after this
- target, but not pull it in. 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>$named</literal>
- facility.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><filename>nss-user-lookup.target</filename></term>
- <listitem>
- <para>A target that should be used as synchronization point
- for all user/group name service lookups. Note that this is
- independent of host/network name lookups for which
- <filename>nss-lookup.target</filename> should be used. All
- services for which the availability of the full user/group
- database is essential should be ordered after this target,
- but not pull it in. Note that system users are always
- resolvable, and hence do not require any special ordering
- against this target.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><filename>remote-fs-pre.target</filename></term>
- <listitem>
- <para>This target unit is automatically ordered before all
- remote mount point units (see above). It can be used to run
- certain units before the remote mounts are established. Note
- that this unit is generally not part of the initial
- transaction, unless the unit that wants to be ordered before
- all remote mounts pulls it in via a
- <varname>Wants=</varname> type dependency. If the unit wants
- to be pulled in by the first remote mount showing up, it
- should use <filename>network-online.target</filename> (see
- above).</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><filename>rpcbind.target</filename></term>
- <listitem>
- <para>The portmapper/rpcbind pulls in this target and orders
- itself before it, to indicate its availability. systemd
- automatically adds dependencies of type
- <varname>After=</varname> for this target unit to all SysV
- init script service units with an LSB header referring to
- the <literal>$portmap</literal> facility.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><filename>time-sync.target</filename></term>
- <listitem>
- <para>Services responsible for synchronizing the system
- clock from a remote source (such as NTP client
- implementations) should pull in this target and order
- themselves before it. All services where correct time is
- essential should be ordered after this unit, but not pull it
- in. 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>
- </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>,
- <filename>timers.target</filename>,
- <filename>paths.target</filename>,
- <filename>bluetooth.target</filename>,
- <filename>printer.target</filename>,
- <filename>smartcard.target</filename>,
- <filename>sound.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
- <constant>SIGTERM</constant> or <constant>SIGINT</constant>
- 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>Special Slice Units</title>
-
- <para>There are four <literal>.slice</literal> units which form
- the basis of the hierarchy for assignment of resources for
- services, users, and virtual machines or containers.</para>
-
- <variablelist>
- <varlistentry>
- <term><filename>-.slice</filename></term>
- <listitem>
- <para>The root slice is the root of the hierarchy. It
- usually does not contain units directly, but may be used to
- set defaults for the whole tree.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><filename>system.slice</filename></term>
- <listitem>
- <para>By default, all services services started by
- <command>systemd</command> are found in this slice.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><filename>user.slice</filename></term>
- <listitem>
- <para>By default, all user processes and services started on
- behalf of the user, including the per-user systemd instance
- are found in this slice.</para>
- </listitem>
- </varlistentry>
-
- <varlistentry>
- <term><filename>machine.slice</filename></term>
- <listitem>
- <para>By default, all virtual machines and containers
- registered with <command>systemd-machined</command> are
- found in this slice.
- </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>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry project='man-pages'><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- </para>
- </refsect1>
-
-</refentry>
~ianmdlvl / elogind.git / blobdiff