<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>reboot.target</filename>,
<filename>remote-fs.target</filename>,
<filename>remote-fs-pre.target</filename>,
- <filename>remote-fs-setup.target</filename>,
<filename>rescue.target</filename>,
<filename>initrd-root-fs.target</filename>,
<filename>rpcbind.target</filename>,
<filename>system-update.target</filename>,
<filename>time-sync.target</filename>,
<filename>timers.target</filename>,
- <filename>umount.target</filename></para>
+ <filename>umount.target</filename>,
+ <filename>-.slice</filename>,
+ <filename>system.slice</filename>,
+ <filename>user.slice</filename>,
+ <filename>machine.slice</filename></para>
</refsynopsisdiv>
<refsect1>
dependencies of type
<varname>Before=</varname> to
<filename>sysroot-usr.mount</filename>
- and all mount points fround in
+ and all mount points found in
<filename>/etc/fstab</filename>
that have the
<option>auto</option> and
this unit during
installation. This is best
configured via
- <varname>WantedBy=multi-uer.target</varname>
+ <varname>WantedBy=multi-user.target</varname>
in the unit's
<literal>[Install]</literal>
section.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><filename>network.target</filename></term>
+ <term><filename>network-online.target</filename></term>
<listitem>
- <para>systemd automatically
- adds dependencies of type
- <varname>After=</varname> for
- this target unit to all SysV
- init script service units with
- an LSB header referring to the
- <literal>$network</literal>
- facility.</para>
+ <para>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>This unit is supposed to
- indicate when the network is
- "up", but it is only very
- loosely defined what that is
- supposed to mean. Also see <ulink
+ <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>
- </listitem>
+
+ <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>
facility.</para>
</listitem>
</varlistentry>
- <varlistentry>
- <term><filename>remote-fs-setup.target</filename></term>
- <listitem>
- <para>This target unit is
- automatically pulled in (by a
- <varname>Wants=</varname> type
- dependency) by all remote
- mount points. It can be used
- to run certain units when at
- least one remote file system
- is to be mounted. Note that
- this target is not ordered
- against the remote mounts, use
- <filename>remote-fs-pre.target</filename>
- for that (see below).</para>
-
- <para>Again, this target unit
- is <emphasis>not</emphasis>
- suitable for ordering, it is
- only useful for pulling in
- other units.</para>
- </listitem>
- </varlistentry>
<varlistentry>
<term><filename>rescue.target</filename></term>
<listitem>
available at boot.</para>
<para>This may be used to pull
- in printer management
+ in smartcard management
daemons dynamically when
smartcard hardware is
found.</para>
<para>This may be used to pull
in audio management daemons
- dynamically when printer
+ dynamically when audio
hardware is found.</para>
</listitem>
</varlistentry>
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>
+ 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
(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>local-fs-pre.target</filename></term>
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>
user/group name lookups for
which
<filename>nss-user-lookup.target</filename>
- should be used. systemd
+ 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
host/network name lookups for
which
<filename>nss-lookup.target</filename>
- should be used. </para>
+ 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>
<varname>Wants=</varname> type
dependency. If the unit wants
to be pulled in by the first
- remote mount showing up it
+ remote mount showing up, it
should use
- <filename>remote-fs-setup.target</filename>
+ <filename>network-online.target</filename>
(see above).</para>
-
- <para>Again, this target unit
- is <emphasis>not</emphasis>
- suitable for pulling in other
- units, it is only useful for
- ordering.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>rpcbind.target</filename></term>
<listitem>
- <para>systemd automatically
- adds dependencies of type
+ <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
<varlistentry>
<term><filename>time-sync.target</filename></term>
<listitem>
- <para>systemd automatically
- adds dependencies of type
+ <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>
+ facility. </para>
</listitem>
</varlistentry>
</variablelist>
<filename>smartcard.target</filename>,
<filename>sound.target</filename>.</para>
- <para>In addition the following special unit is
+ <para>In addition, the following special unit is
understood only when systemd runs as service instance:</para>
<variablelist>
terminate the user service
manager should start this
unit. If systemd receives
- SIGTERM or SIGINT when running
- as user service daemon it will
+ <constant>SIGTERM</constant> or <constant>SIGINT</constant> when running
+ as user service daemon, it will
start this unit.</para>
<para>Normally, this pulls in
</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 defalt, 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.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><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>