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| author | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2015-02-03 21:14:13 -0500 |
|---|---|---|
| committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2015-02-03 23:11:35 -0500 |
| commit | 798d3a524ea57aaf40cb53858aaa45ec702f012d (patch) | |
| tree | f9251ab7878a180d464780d514f3ea8d4599fe6e /man/systemd.special.xml | |
| parent | 35888b67f77fa7a5cae0973403cb97aa30cad70c (diff) | |
Reindent man pages to 2ch
Diffstat (limited to 'man/systemd.special.xml')
| -rw-r--r-- | man/systemd.special.xml | 1988 |
1 files changed, 850 insertions, 1138 deletions
diff --git a/man/systemd.special.xml b/man/systemd.special.xml index 863d7f35d9..cf76aaf607 100644 --- a/man/systemd.special.xml +++ b/man/systemd.special.xml @@ -1,6 +1,6 @@ <?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"> + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. @@ -23,1142 +23,854 @@ <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> + <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> |