Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ 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
- General Public License for more details.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refnamediv>
<refname>systemd.special</refname>
- <refpurpose>special systemd units</refpurpose>
+ <refpurpose>Special systemd units</refpurpose>
</refnamediv>
<refsynopsisdiv>
- <para><filename>basic.target</filename></para>
- <para><filename>ctrl-alt-del.target</filename></para>
- <para><filename>default.target</filename></para>
- <para><filename>emergency.service</filename></para>
- <para><filename>graphical.target</filename></para>
- <para><filename>halt.target</filename></para>
- <para><filename>kbrequest.target</filename></para>
- <para><filename>local-fs.target</filename></para>
- <para><filename>multi-user.target</filename></para>
- <para><filename>network.target</filename></para>
- <para><filename>nss-lookup.target</filename></para>
- <para><filename>poweroff.target</filename></para>
- <para><filename>reboot.target</filename></para>
- <para><filename>remote-fs.target</filename></para>
- <para><filename>rescue.target</filename></para>
- <para><filename>rpcbind.target</filename></para>
- <para><filename>rtc-set.target</filename></para>
- <para><filename>runlevel0.target</filename>,
- <filename>runlevel0.target</filename>,
- <filename>runlevel1.target</filename>,
- <filename>runlevel2.target</filename>,
- <filename>runlevel3.target</filename>,
- <filename>runlevel4.target</filename>,
- <filename>runlevel5.target</filename>,
- <filename>runlevel6.target</filename></para>
- <para><filename>shutdown.target</filename></para>
- <para><filename>sigpwr.target</filename></para>
- <para><filename>sockets.target</filename></para>
- <para><filename>swap.target</filename></para>
- <para><filename>syslog.target</filename></para>
- <para><filename>systemd-initctl.service</filename>, <filename>systemd-initctl.socket</filename></para>
- <para><filename>systemd-logger.service</filename>, <filename>systemd-logger.socket</filename></para>
+ <para><filename>basic.target</filename>,
+ <filename>ctrl-alt-del.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.service</filename>,
+ <filename>final.service</filename>,
+ <filename>graphical.target</filename>,
+ <filename>hibernate.target</filename>,
+ <filename>http-daemon.target</filename>,
+ <filename>halt.target</filename>,
+ <filename>kbrequest.target</filename>,
+ <filename>kexec.target</filename>,
+ <filename>local-fs.target</filename>,
+ <filename>local-fs-pre.target</filename>,
+ <filename>mail-transfer-agent.target</filename>,
+ <filename>multi-user.target</filename>,
+ <filename>network.target</filename>,
+ <filename>nss-lookup.target</filename>,
+ <filename>poweroff.target</filename>,
+ <filename>reboot.target</filename>,
+ <filename>remote-fs.target</filename>,
+ <filename>remote-fs-pre.target</filename>,
+ <filename>rescue.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>sockets.target</filename>,
+ <filename>suspend.target</filename>,
+ <filename>swap.target</filename>,
+ <filename>sysinit.target</filename>,
+ <filename>syslog.service</filename>,
+ <filename>syslog.socket</filename>,
+ <filename>syslog.target</filename>,
+ <filename>time-sync.target</filename>,
+ <filename>umount.target</filename></para>
</refsynopsisdiv>
<refsect1>
target unit to all SysV
service units configured for
runlevel 1 to 5.</para>
- <para>systemd automatically
- adds dependencies of the types
- Wants and After for all
- SysV service units configured
- for runlevels that are not 0
- to 6 to this target unit.
- This covers the special
- boot-up runlevels some
- distributions have, such as S
- or b.</para>
+ <para>Usually this should pull-in
+ all sockets, mount points,
+ swap devices and other basic
+ initialization necessary for
+ the general purpose
+ daemons. Most normal daemons
+ should have dependencies of
+ type After and Requires on
+ this unit.</para>
</listitem>
</varlistentry>
<varlistentry>
<filename>reboot.target</filename>.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><filename>dbus.service</filename></term>
+ <listitem>
+ <para>A special unit for the
+ D-Bus system bus. 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
+ <literal>Type=dbus</literal>
+ automatically gain a
+ dependency on this
+ unit.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><filename>default.target</filename></term>
<listitem>
<filename>graphical.target</filename>.</para>
<para>The default unit systemd
starts at bootup can be
- overriden with the
- <varname>systemd.default=</varname>
+ overridden with the
+ <varname>systemd.unit=</varname>
kernel command line option.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><filename>emergency.service</filename></term>
+ <term><filename>display-manager.service</filename></term>
<listitem>
- <para>A special service unit
+ <para>The display manager
+ service. Usually this should
+ be aliased (symlinked) to
+ <filename>gdm.service</filename>
+ or a similar display manager
+ service.</para>
+ <para>systemd automatically
+ adds dependencies of type
+ After for this target unit to
+ all SysV init script service
+ units with a LSB header
+ referring to the
+ <literal>$x-display-manager</literal>
+ facility, for compatibility
+ with Debian.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>emergency.target</filename></term>
+ <listitem>
+ <para>A special target unit
that starts an emergency
shell on the main
console. This unit is supposed
to be used with the kernel
command line option
- <varname>systemd.default=</varname>
+ <varname>systemd.unit=</varname>
and has otherwise little use.
</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><filename>final.target</filename></term>
+ <listitem>
+ <para>A special target unit
+ that is used during the
+ shutdown logic and may be used
+ to pull in late services after
+ all normal services are
+ already terminated and all
+ mounts unmounted.
+ </para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><filename>graphical.target</filename></term>
<listitem>
during installation.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><filename>hibernate.target</filename></term>
+ <listitem>
+ <para>A special target unit
+ for hibernating the
+ system. This pulls in
+ <filename>sleep.target</filename>.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>http-daemon.target</filename></term>
+ <listitem>
+ <para>A target for pulling in
+ an HTTP server if there is
+ any.</para>
+ <para>systemd automatically
+ adds dependencies of type
+ After for this target unit to
+ all SysV init script service
+ units with a LSB header
+ referring to the
+ <literal>$httpd</literal>
+ facility.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><filename>halt.target</filename></term>
<listitem>
<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>
mounts listed in
<filename>/etc/fstab</filename>
that have the
- <literal>auto</literal> and
- <literal>comment=systemd.mount</literal>
+ <option>auto</option> and
+ <option>comment=systemd.mount</option>
mount options set.</para>
<para>systemd automatically
facility.</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>mail-transfer-agent.target</filename></term>
+ <listitem>
+ <para>The mail transfer agent
+ (MTA) service. Usually this
+ should pull-in all units
+ necessary for
+ sending/receiving mails on the
+ local host.</para>
+
+ <para>systemd automatically
+ adds dependencies of type
+ After for this target unit to
+ all SysV init script service
+ units with an LSB header
+ referring to the
+ <literal>$mail-transfer-agent</literal>
+ or
+ <literal>$mail-transport-agent</literal>
+ facilities, for compatibility
+ with Debian.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><filename>multi-user.target</filename></term>
<listitem>
<varlistentry>
<term><filename>nss-lookup.target</filename></term>
<listitem>
- <para>systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
+ <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 After for
+ this target unit to all SysV
+ init script service units with
+ an LSB header referring to the
<literal>$named</literal>
facility.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><filename>nss-user-lookup.target</filename></term>
+ <listitem>
+ <para>A target that should be
+ used as synchronization point
+ for all user/group name
+ service lookups. Note that
+ this is independent of
+ host/network name lookups for
+ which
+ <filename>nss-lookup.target</filename>
+ should be used. </para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><filename>poweroff.target</filename></term>
<listitem>
all SysV init script service
units with an LSB header
referring to the
- <literal>$remote-fs</literal>
+ <literal>$remote_fs</literal>
facility.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><filename>remote-fs-pre.target</filename></term>
+ <listitem>
+ <para>This target unit is
+ automatically ordered before
+ all remote mount points marked
+ with <option>auto</option>
+ (see above). It can be used to
+ execute certain units before
+ all remote mounts.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><filename>rescue.target</filename></term>
<listitem>
facility.</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><filename>rtc-set.target</filename></term>
- <listitem>
- <para>systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- <literal>$time</literal>
- facility.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><filename>runlevel0.target</filename></term>
- <listitem>
- <para>This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 0. This is an alias
- for
- <filename>poweroff.target</filename>,
- for compatibility with
- SysV.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><filename>runlevel1.target</filename></term>
- <listitem>
- <para>This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 1. This is an alias
- for
- <filename>rescue.target</filename>,
- for compatibility with
- SysV.</para>
- </listitem>
- </varlistentry>
<varlistentry>
<term><filename>runlevel2.target</filename></term>
<listitem>
<para>This is a target that is
- called whever the SysV
+ called whenever the SysV
compatibility code asks for
runlevel 2. It is a good idea
to make this an alias for
<term><filename>runlevel3.target</filename></term>
<listitem>
<para>This is a target that is
- called whever the SysV
+ called whenever the SysV
compatibility code asks for
runlevel 3. It is a good idea
to make this an alias for
<term><filename>runlevel4.target</filename></term>
<listitem>
<para>This is a target that is
- called whever the SysV
+ called whenever the SysV
compatibility code asks for
runlevel 4. It is a good idea
to make this an alias for
<term><filename>runlevel5.target</filename></term>
<listitem>
<para>This is a target that is
- called whever the SysV
+ called whenever the SysV
compatibility code asks for
runlevel 5. It is a good idea
to make this an alias for
<filename>graphical.target</filename>.</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><filename>runlevel6.target</filename></term>
- <listitem>
- <para>This is a target that is
- called whever the SysV
- compatibility code asks for
- runlevel 6. This is an alias
- for
- <filename>reboot.target</filename>,
- for compatibility with
- SysV.</para>
- </listitem>
- </varlistentry>
<varlistentry>
<term><filename>shutdown.target</filename></term>
<listitem>
terminated on system shutdown
shall add Conflicts
dependencies to this unit for
- their service unit during
- installation.</para>
+ their service unit, which is
+ implicitly done when
+ <varname>DefaultDependencies=yes</varname>
+ is set (the default).</para>
<para>systemd automatically
adds dependencies of type
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>
+ and
+ <filename>hibernate.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>
during installation.</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>
</listitem>
</varlistentry>
<varlistentry>
- <term><filename>syslog.target</filename></term>
+ <term><filename>sysinit.target</filename></term>
<listitem>
+ <para>A special target unit
+ covering early boot-up scripts.</para>
<para>systemd automatically
- adds dependencies of type
- After for this target unit to
- all SysV init script service
- units with an LSB header
- referring to the
- <literal>$syslog</literal>
- facility.</para>
-
- <para>Administrators should
- ensure that this target pulls
- in a service unit with the
- name or alias of
- <filename>@SPECIAL_SYSLOG_SERVICE@</filename>
- (or a socket unit that
- activates this
- service).</para>
+ adds dependencies of the types
+ Wants and After for all
+ SysV service units configured
+ for runlevels that are not 0
+ to 6 to this target unit.
+ This covers the special
+ boot-up runlevels some
+ distributions have, such as S
+ or b.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><filename>syslog.service</filename></term>
+ <listitem>
+ <para>The syslog service if
+ any. Implementations should
+ create a symlink from the
+ actual syslog implementation
+ to this generic name for
+ activating it.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><filename>systemd-initctl.service</filename></term>
+ <term><filename>syslog.socket</filename></term>
<listitem>
- <para>This provides
- compatibility with the SysV
- /dev/initctl file system FIFO
- for communication with the
- init system.</para>
- <para>This is a
- socket-activated service, see
- <filename>system-initctl.socket</filename>.</para>
+ <para>The socket unit where
+ syslog implementations should
+ listen on. All userspace log
+ messages will be made
+ available on this
+ socket.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><filename>systemd-initctl.socket</filename></term>
+ <term><filename>syslog.target</filename></term>
<listitem>
- <para>Socket activation unit
- for
- <filename>system-initctl.service</filename>.</para>
+ <para>systemd automatically
+ adds dependencies of type
+ After for this target unit to
+ all SysV init script service
+ units with an LSB header
+ referring to the
+ <literal>$syslog</literal>
+ facility.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><filename>systemd-logger.service</filename></term>
+ <term><filename>time-sync.target</filename></term>
<listitem>
- <para>This is internally used
- by systemd to provide syslog
- logging to the processes it
- maintains.</para>
- <para>This is a
- socket-activated service, see
- <filename>system-logger.socket</filename>.</para>
+ <para>systemd automatically
+ adds dependencies of type
+ After 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>systemd-logger.socket</filename></term>
+ <term><filename>umount.target</filename></term>
<listitem>
- <para>Socket activation unit
- for
- <filename>system-logger.service</filename>. systemd
- will automatically add
- dependencies of types Requires
- and After to all units that
- have been configured for
- stdout or stderr to be
- connected to syslog or the
- kernel log buffer.</para>
+ <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 Session Units</title>
+ <title>Special User Units</title>
- <para>When systemd runs as a service instance, the
+ <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>local-fs.target</filename>,
- <filename>remote-fs.target</filename>,
<filename>shutdown.target</filename>,
- <filename>sockets.target</filename>,
- <filename>swap.target</filename>.</para>
+ <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.service</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.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</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>
</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff