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diff --git a/man/systemd.special.xml b/man/systemd.special.xml new file mode 100644 index 0000000000..116a43ccfb --- /dev/null +++ b/man/systemd.special.xml @@ -0,0 +1,725 @@ +<?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 General Public License as published by + the Free Software Foundation; either version 2 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. + + You should have received a copy of the GNU 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>ctrl-alt-del.target</filename>, + <filename>dbus.service</filename>, + <filename>default.target</filename>, + <filename>display-manager.service</filename>, + <filename>emergency.target</filename>, + <filename>exit.service</filename>, + <filename>graphical.target</filename>, + <filename>halt.target</filename>, + <filename>kbrequest.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>sockets.target</filename>, + <filename>swap.target</filename>, + <filename>sysinit.target</filename>, + <filename>syslog.target</filename>, + <filename>systemd-initctl.service</filename>, + <filename>systemd-initctl.socket</filename>, + <filename>systemd-stdout-syslog-bridge.service</filename>, + <filename>systemd-stdout-syslog-bridge.socket</filename>, + <filename>time-sync.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 early boot-up.</para> + <para>systemd automatically + adds dependencies of the types + Requires and After for this + target unit to all SysV + service units configured for + runlevel 1 to 5.</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> + <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>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>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>xdm.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.unit=</varname> + and has otherwise little use. + </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 login shall add + Wants dependencies for their + unit to this unit (or + <filename>multi-user.target</filename>) + during installation.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>halt.target</filename></term> + <listitem> + <para>A special target unit + for shutting down and halting the system.</para> + + <para>Applications wanting to + halt the system should start + this unit.</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>local-fs.target</filename></term> + <listitem> + <para>systemd automatically + adds dependencies of type + After to all mount units that + refer to local mount points + for this target unit. In + addition, systemd adds + dependencies of type Wants to + this target unit for those + mounts listed in + <filename>/etc/fstab</filename> + that have the + <option>auto</option> and + <option>comment=systemd.mount</option> + mount options set.</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>$local_fs</literal> + 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> + <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 Wants dependencies to + this unit for their unit during + installation.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>network.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>$network</literal> + facility.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>nss-lookup.target</filename></term> + <listitem> + <para>systemd automatically + adds dependencies of type + After for this target unit to + all SysV init script service + units with an LSB header + referring to the + <literal>$named</literal> + facility.</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 + After for this target unit to + all SysV init script service + units with an LSB header + referring to the + <literal>$remote_fs</literal> + facility.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>remote-fs-pre.target</filename></term> + <listitem> + <para>This target unit is + automatically ordered before + all remote mount points marked + with <option>auto</option> + (see above). It can be used to + execute certain units before + all remote mounts.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>rescue.target</filename></term> + <listitem> + <para>A special target unit + for setting up the base system + and a rescue shell.</para> + + <para><filename>runlevel1.target</filename> + is an alias for this target + unit, for compatibility with SysV.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>rpcbind.target</filename></term> + <listitem> + <para>systemd automatically + adds dependencies of type + After for this target unit to + all SysV init script service + units with an LSB header + referring to the + <literal>$rpcbind</literal> + facility.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>runlevel2.target</filename></term> + <listitem> + <para>This is a target that is + called whenever the SysV + compatibility code asks for + runlevel 2. It is a good idea + to make this an alias for + (i.e. symlink to) + <filename>multi-user.target</filename>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>runlevel3.target</filename></term> + <listitem> + <para>This is a target that is + called whenever the SysV + compatibility code asks for + runlevel 3. It is a good idea + to make this an alias for + (i.e. symlink to) + <filename>multi-user.target</filename> + or + <filename>graphical.target</filename>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>runlevel4.target</filename></term> + <listitem> + <para>This is a target that is + called whenever the SysV + compatibility code asks for + runlevel 4. It is a good idea + to make this an alias for + (i.e. symlink to) + <filename>multi-user.target</filename> + or + <filename>graphical.target</filename>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>runlevel5.target</filename></term> + <listitem> + <para>This is a target that is + called whenever the SysV + compatibility code asks for + runlevel 5. It is a good idea + to make this an alias for + (i.e. symlink to) + <filename>multi-user.target</filename> + or + <filename>graphical.target</filename>.</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 Conflicts + dependencies to this unit for + their service unit, which is + implicitly done when + <varname>DefaultDependencies=yes</varname> + is set (the default).</para> + + <para>systemd automatically + adds dependencies of type + Conflicts to this target unit + for all SysV init script + service units that shall be + terminated in SysV runlevels 0 + or 6.</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>sockets.target</filename></term> + <listitem> + <para>A special target unit + that sets up all service + sockets.</para> + + <para>Services that can be + socket-activated shall add + Wants dependencies to this + unit for their socket unit + during installation.</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> + <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> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>syslog.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>$syslog</literal> + facility.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>systemd-initctl.service</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> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>systemd-initctl.socket</filename></term> + <listitem> + <para>Socket activation unit + for + <filename>system-initctl.service</filename>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>systemd-stdout-syslog-bridge.service</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-stdout-syslog-bridge.socket</filename>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>systemd-stdout-syslog-bridge.socket</filename></term> + <listitem> + <para>Socket activation unit + for + <filename>system-stdout-syslog-bridge.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> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>systemd-shutdownd.service</filename></term> + <listitem> + <para>This is internally used + by + <citerefentry><refentrytitle>shutdown</refentrytitle><manvolnum>8</manvolnum></citerefentry> + to implement delayed shutdowns.</para> + <para>This is a + socket-activated service, see + <filename>system-shutdownd.socket</filename>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>systemd-shutdownd.socket</filename></term> + <listitem> + <para>Socket activation unit + for + <filename>system-shutdownd.service</filename>.</para> + </listitem> + </varlistentry> + <varlistentry> + <term><filename>time-sync.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>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>local-fs.target</filename>, + <filename>remote-fs.target</filename>, + <filename>shutdown.target</filename>, + <filename>sockets.target</filename>, + <filename>swap.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.target</refentrytitle><manvolnum>5</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |