This hopefully reduces confusion resulting in issues like #2992.
<para>An implicit <varname>Before=</varname> dependency is created
between an automount unit and the mount unit it activates.</para>
- <para>Automount units acquire automatic <varname>Before=</varname>
- and <varname>Conflicts=</varname> on
- <filename>umount.target</filename> in order to be stopped during
- shutdown, unless <varname>DefaultDependencies=no</varname> is
- set.</para>
+ <para>Automount units acquire automatic <varname>Before=</varname> and <varname>Conflicts=</varname> on
+ <filename>umount.target</filename> in order to be stopped during shutdown, unless
+ <varname>DefaultDependencies=no</varname> is set in the <literal>[Unit]</literal> section.</para>
</refsect1>
<filename>systemd-quotacheck.service</filename> and
<filename>quotaon.service</filename> are added.</para>
- <para>For mount units with
- <varname>DefaultDependencies=yes</varname> (the default) a couple
- additional dependencies are added. Mount units referring to local
- file systems automatically gain an <varname>After=</varname>
- dependency on <filename>local-fs-pre.target</filename>. Network
- mount units automatically acquire <varname>After=</varname>
- dependencies on <filename>remote-fs-pre.target</filename>,
- <filename>network.target</filename> and
- <filename>network-online.target</filename>. Towards the latter a
- <varname>Wants=</varname> unit is added as well. Mount units
- referring to local and network file systems are distinguished by
- their file system type specification. In some cases this is not
- sufficient (for example network block device based mounts, such as
- iSCSI), in which case <option>_netdev</option> may be added to the
- mount option string of the unit, which forces systemd to consider the
- mount unit a network mount. Mount units (regardless if local or
- network) also acquire automatic <varname>Before=</varname> and
- <varname>Conflicts=</varname> on
- <filename>umount.target</filename> in order to be stopped
- during shutdown.</para>
+ <para>For mount units with <varname>DefaultDependencies=yes</varname> in the <literal>[Unit]</literal> section (the
+ default) a couple additional dependencies are added. Mount units referring to local file systems automatically gain
+ an <varname>After=</varname> dependency on <filename>local-fs-pre.target</filename>. Network mount units
+ automatically acquire <varname>After=</varname> dependencies on <filename>remote-fs-pre.target</filename>,
+ <filename>network.target</filename> and <filename>network-online.target</filename>. Towards the latter a
+ <varname>Wants=</varname> unit is added as well. Mount units referring to local and network file systems are
+ distinguished by their file system type specification. In some cases this is not sufficient (for example network
+ block device based mounts, such as iSCSI), in which case <option>_netdev</option> may be added to the mount option
+ string of the unit, which forces systemd to consider the mount unit a network mount. Mount units (regardless if
+ local or network) also acquire automatic <varname>Before=</varname> and <varname>Conflicts=</varname> on
+ <filename>umount.target</filename> in order to be stopped during shutdown.</para>
<para>Additional implicit dependencies may be added as result of
execution and resource control parameters as documented in
<para>An implicit <varname>Before=</varname> dependency is added
between a path unit and the unit it is supposed to activate.</para>
- <para>Unless <varname>DefaultDependencies=false</varname> is used,
- path units will implicitly have dependencies of type
- <varname>Before=</varname> on <filename>paths.target</filename>,
- dependencies of type <varname>After=</varname> and
- <varname>Requires=</varname> on
- <filename>sysinit.target</filename>, and have dependencies of type
- <varname>Conflicts=</varname> and <varname>Before=</varname> on
- <filename>shutdown.target</filename>. These ensure that path units
- are terminated cleanly prior to system shutdown. Only path units
- involved with early boot or late system shutdown should disable
+ <para>Unless <varname>DefaultDependencies=false</varname> in the <literal>[Unit]</literal> section is used, path
+ units will implicitly have dependencies of type <varname>Before=</varname> on <filename>paths.target</filename>,
+ dependencies of type <varname>After=</varname> and <varname>Requires=</varname> on
+ <filename>sysinit.target</filename>, and have dependencies of type <varname>Conflicts=</varname> and
+ <varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that path units are terminated
+ cleanly prior to system shutdown. Only path units involved with early boot or late system shutdown should disable
this option.
</para>
</refsect1>
their activated <filename>.socket</filename> units via an
automatic <varname>After=</varname> dependency.</para>
- <para>Unless <varname>DefaultDependencies=</varname> is set to
- <option>false</option>, service units will implicitly have
- dependencies of type <varname>Requires=</varname> and
- <varname>After=</varname> on <filename>sysinit.target</filename>,
- a dependency of type <varname>After=</varname> on
- <filename>basic.target</filename> as well as dependencies of
- type <varname>Conflicts=</varname> and <varname>Before=</varname>
- on <filename>shutdown.target</filename>. These ensure that normal
- service units pull in basic system initialization, and are
- terminated cleanly prior to system shutdown. Only services
- involved with early boot or late system shutdown should disable
- this option.</para>
+ <para>Unless <varname>DefaultDependencies=</varname> in the <literal>[Unit]</literal> is set to
+ <option>false</option>, service units will implicitly have dependencies of type <varname>Requires=</varname> and
+ <varname>After=</varname> on <filename>sysinit.target</filename>, a dependency of type <varname>After=</varname> on
+ <filename>basic.target</filename> as well as dependencies of type <varname>Conflicts=</varname> and
+ <varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that normal service units pull in
+ basic system initialization, and are terminated cleanly prior to system shutdown. Only services involved with early
+ boot or late system shutdown should disable this option.</para>
<para>Instanced service units (i.e. service units with an <literal>@</literal> in their name) are assigned by
default a per-template slice unit (see
<varname>After=</varname> and <varname>Requires=</varname> on
their immediate parent slice unit.</para>
- <para>Unless <varname>DefaultDependencies=false</varname>
- is used, slice units will implicitly have dependencies of
- type <varname>Conflicts=</varname> and
- <varname>Before=</varname> on
- <filename>shutdown.target</filename>. These ensure
- that slice units are removed prior to system
- shutdown. Only slice units involved with early boot or
- late system shutdown should disable this option.
+ <para>Unless <varname>DefaultDependencies=false</varname> is used in the <literal>[Unit]</literal> section, slice
+ units will implicitly have dependencies of type <varname>Conflicts=</varname> and <varname>Before=</varname> on
+ <filename>shutdown.target</filename>. These ensure that slice units are removed prior to system shutdown. Only
+ slice units involved with early boot or late system shutdown should disable this option.
</para>
</refsect1>
<filename>foo@.service</filename> must exist from which services
are instantiated for each incoming connection.</para>
- <para>Unless <varname>DefaultDependencies=</varname> is set to
- <option>false</option>, socket units will implicitly have
- dependencies of type <varname>Requires=</varname> and
- <varname>After=</varname> on <filename>sysinit.target</filename>
- as well as dependencies of type <varname>Conflicts=</varname> and
- <varname>Before=</varname> on
- <filename>shutdown.target</filename>. These ensure that socket
- units pull in basic system initialization, and are terminated
- cleanly prior to system shutdown. Only sockets involved with early
- boot or late system shutdown should disable this option.</para>
+ <para>Unless <varname>DefaultDependencies=</varname> in the <literal>[Unit]</literal> section is set to
+ <option>false</option>, socket units will implicitly have dependencies of type <varname>Requires=</varname> and
+ <varname>After=</varname> on <filename>sysinit.target</filename> as well as dependencies of type
+ <varname>Conflicts=</varname> and <varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure
+ that socket units pull in basic system initialization, and are terminated cleanly prior to system shutdown. Only
+ sockets involved with early boot or late system shutdown should disable this option.</para>
<para>Socket units will have a <varname>Before=</varname>
dependency on the service which they trigger added implicitly. No
dependencies on the device units or the mount units of the files
they are activated from.</para>
- <para>Swap units with <varname>DefaultDependencies=</varname>
- enabled implicitly acquire a <varname>Conflicts=</varname> and an
- <varname>After=</varname> dependency on
- <filename>umount.target</filename> so that they are deactivated at
- shutdown, unless <varname>DefaultDependencies=no</varname> is
- specified.</para>
+ <para>Swap units with <varname>DefaultDependencies=</varname> in the <literal>[Unit]</literal> section enabled
+ implicitly acquire a <varname>Conflicts=</varname> and an <varname>After=</varname> dependency on
+ <filename>umount.target</filename> so that they are deactivated at shutdown, unless
+ <varname>DefaultDependencies=no</varname> is specified.</para>
<para>Additional implicit dependencies may be added as result of
execution and resource control parameters as documented in
<refsect1>
<title>Automatic Dependencies</title>
- <para>Unless <varname>DefaultDependencies=</varname> is set to
- <option>no</option>, target units will implicitly complement all
- configured dependencies of type <varname>Wants=</varname>,
- <varname>Requires=</varname> with dependencies of type
- <varname>After=</varname>, unless an ordering dependency of any
- kind between the target and the respective other unit is already
- in place. Note that this behaviour is disabled if either unit has
- <varname>DefaultDependencies=no</varname>.</para>
+ <para>Unless <varname>DefaultDependencies=</varname> in the <literal>[Unit]</literal> section is set to
+ <option>no</option>, target units will implicitly complement all configured dependencies of type
+ <varname>Wants=</varname>, <varname>Requires=</varname> with dependencies of type <varname>After=</varname>, unless
+ an ordering dependency of any kind between the target and the respective other unit is already in place. Note that
+ this behaviour is disabled if either unit has <varname>DefaultDependencies=no</varname>.</para>
</refsect1>
<refsect1>
<para>Timer units automatically gain a <varname>Before=</varname>
dependency on the service they are supposed to activate.</para>
- <para>Unless <varname>DefaultDependencies=</varname> is set to
- <option>false</option>, all timer units will implicitly have
- dependencies of type <varname>Requires=</varname> and
- <varname>After=</varname> on <filename>sysinit.target</filename>,
- a dependency of type <varname>Before=</varname> on
- <filename>timers.target</filename>, as well as
- <varname>Conflicts=</varname> and <varname>Before=</varname> on
- <filename>shutdown.target</filename> to ensure that they are
- stopped cleanly prior to system shutdown. Timer units with at
- least one <varname>OnCalendar=</varname> directive will have an
- additional <varname>After=</varname> dependency on
- <filename>timer-sync.target</filename> to avoid being started
- before the system clock has been correctly set. Only timer units
- involved with early boot or late system shutdown should disable
- the <varname>DefaultDependencies=</varname> option.</para>
+ <para>Unless <varname>DefaultDependencies=</varname> in the <literal>[Unit]</literal> section is set to
+ <option>false</option>, all timer units will implicitly have dependencies of type <varname>Requires=</varname> and
+ <varname>After=</varname> on <filename>sysinit.target</filename>, a dependency of type <varname>Before=</varname>
+ on <filename>timers.target</filename>, as well as <varname>Conflicts=</varname> and <varname>Before=</varname> on
+ <filename>shutdown.target</filename> to ensure that they are stopped cleanly prior to system shutdown. Timer units
+ with at least one <varname>OnCalendar=</varname> directive will have an additional <varname>After=</varname>
+ dependency on <filename>timer-sync.target</filename> to avoid being started before the system clock has been
+ correctly set. Only timer units involved with early boot or late system shutdown should disable the
+ <varname>DefaultDependencies=</varname> option.</para>
</refsect1>
<refsect1>
projects / thirdparty / systemd.git / commitdiff
