man/systemd.timer.xml - systemd-stable - Rivoreo Source Code Repositories

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 <!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 Lesser General Public License as published by
   the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.

   systemd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 -->

 <refentry id="systemd.timer">
   <refentryinfo>
     <title>systemd.timer</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.timer</refentrytitle>
     <manvolnum>5</manvolnum>
   </refmeta>

   <refnamediv>
     <refname>systemd.timer</refname>
     <refpurpose>Timer unit configuration</refpurpose>
   </refnamediv>

   <refsynopsisdiv>
     <para><filename><replaceable>timer</replaceable>.timer</filename></para>
   </refsynopsisdiv>

   <refsect1>
     <title>Description</title>

     <para>A unit configuration file whose name ends in
     <literal>.timer</literal> encodes information about a timer
     controlled and supervised by systemd, for timer-based
     activation.</para>

     <para>This man page lists the configuration options specific to
     this unit type. See
     <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
     for the common options of all unit configuration files. The common
     configuration items are configured in the generic [Unit] and
     [Install] sections. The timer specific configuration options are
     configured in the [Timer] section.</para>

     <para>For each timer file, a matching unit file must exist,
     describing the unit to activate when the timer elapses. By
     default, a service by the same name as the timer (except for the
     suffix) is activated. Example: a timer file
     <filename>foo.timer</filename> activates a matching service
     <filename>foo.service</filename>. The unit to activate may be
     controlled by <varname>Unit=</varname> (see below).</para>

     <para>Note that in case the unit to activate is already active at the time the timer elapses it is not restarted,
     but simply left running. There is no concept of spawning new service instances in this case. Due to this, services
     with <varname>RemainAfterExit=</varname> set (which stay around continuously even after the service's main process
     exited) are usually not suitable for activation via repetitive timers, as they will only be activated once, and
     then stay around forever.</para>
   </refsect1>

   <refsect1>
     <title>Automatic Dependencies</title>

     <para>Timer units automatically gain a <varname>Before=</varname>
     dependency on the service they are supposed to activate.</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>time-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>
     <title>Options</title>

     <para>Timer files must include a [Timer] section, which carries
     information about the timer it defines. The options specific to
     the [Timer] section of timer units are the following:</para>

     <variablelist class='unit-directives'>
       <varlistentry>
         <term><varname>OnActiveSec=</varname></term>
         <term><varname>OnBootSec=</varname></term>
         <term><varname>OnStartupSec=</varname></term>
         <term><varname>OnUnitActiveSec=</varname></term>
         <term><varname>OnUnitInactiveSec=</varname></term>

         <listitem><para>Defines monotonic timers relative to different
         starting points: <varname>OnActiveSec=</varname> defines a
         timer relative to the moment the timer itself is activated.
         <varname>OnBootSec=</varname> defines a timer relative to when
         the machine was booted up. <varname>OnStartupSec=</varname>
         defines a timer relative to when systemd was first started.
         <varname>OnUnitActiveSec=</varname> defines a timer relative
         to when the unit the timer is activating was last activated.
         <varname>OnUnitInactiveSec=</varname> defines a timer relative
         to when the unit the timer is activating was last
         deactivated.</para>

         <para>Multiple directives may be combined of the same and of
         different types. For example, by combining
         <varname>OnBootSec=</varname> and
         <varname>OnUnitActiveSec=</varname>, it is possible to define
         a timer that elapses in regular intervals and activates a
         specific service each time.</para>

         <para>The arguments to the directives are time spans
         configured in seconds. Example: "OnBootSec=50" means 50s after
         boot-up. The argument may also include time units. Example:
         "OnBootSec=5h 30min" means 5 hours and 30 minutes after
         boot-up. For details about the syntax of time spans, see
         <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>

         <para>If a timer configured with <varname>OnBootSec=</varname>
         or <varname>OnStartupSec=</varname> is already in the past
         when the timer unit is activated, it will immediately elapse
         and the configured unit is started. This is not the case for
         timers defined in the other directives.</para>

         <para>These are monotonic timers, independent of wall-clock
         time and timezones. If the computer is temporarily suspended,
         the monotonic clock stops too.</para>

         <para>If the empty string is assigned to any of these options,
         the list of timers is reset, and all prior assignments will
         have no effect.</para>

         <para>Note that timers do not necessarily expire at the
         precise time configured with these settings, as they are
         subject to the <varname>AccuracySec=</varname> setting
         below.</para></listitem>

       </varlistentry>

       <varlistentry>
         <term><varname>OnCalendar=</varname></term>

         <listitem><para>Defines realtime (i.e. wallclock) timers with
         calendar event expressions. See
         <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
         for more information on the syntax of calendar event
         expressions. Otherwise, the semantics are similar to
         <varname>OnActiveSec=</varname> and related settings.</para>

         <para>Note that timers do not necessarily expire at the
         precise time configured with this setting, as it is subject to
         the <varname>AccuracySec=</varname> setting
         below.</para>

        <para>May be specified more than once.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><varname>AccuracySec=</varname></term>

         <listitem><para>Specify the accuracy the timer shall elapse
         with. Defaults to 1min. The timer is scheduled to elapse
         within a time window starting with the time specified in
         <varname>OnCalendar=</varname>,
         <varname>OnActiveSec=</varname>,
         <varname>OnBootSec=</varname>,
         <varname>OnStartupSec=</varname>,
         <varname>OnUnitActiveSec=</varname> or
         <varname>OnUnitInactiveSec=</varname> and ending the time
         configured with <varname>AccuracySec=</varname> later. Within
         this time window, the expiry time will be placed at a
         host-specific, randomized, but stable position that is
         synchronized between all local timer units. This is done in
         order to optimize power consumption to suppress unnecessary
         CPU wake-ups. To get best accuracy, set this option to
         1us. Note that the timer is still subject to the timer slack
         configured via
         <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>'s
         <varname>TimerSlackNSec=</varname> setting. See
         <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
         for details. To optimize power consumption, make sure to set
         this value as high as possible and as low as
         necessary.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><varname>RandomizedDelaySec=</varname></term>

         <listitem><para>Delay the timer by a randomly selected, evenly
         distributed amount of time between 0 and the specified time
         value. Defaults to 0, indicating that no randomized delay
         shall be applied. Each timer unit will determine this delay
         randomly each time it is started, and the delay will simply be
         added on top of the next determined elapsing time. This is
         useful to stretch dispatching of similarly configured timer
         events over a certain amount time, to avoid that they all fire
         at the same time, possibly resulting in resource
         congestion. Note the relation to
         <varname>AccuracySec=</varname> above: the latter allows the
         service manager to coalesce timer events within a specified
         time range in order to minimize wakeups, the former does the
         opposite: it stretches timer events over a time range, to make
         it unlikely that they fire simultaneously. If
         <varname>RandomizedDelaySec=</varname> and
         <varname>AccuracySec=</varname> are used in conjunction, first
         the randomized delay is added, and then the result is
         possibly further shifted to coalesce it with other timer
         events happening on the system. As mentioned above
         <varname>AccuracySec=</varname> defaults to 1min and
         <varname>RandomizedDelaySec=</varname> to 0, thus encouraging
         coalescing of timer events. In order to optimally stretch
         timer events over a certain range of time, make sure to set
         <varname>RandomizedDelaySec=</varname> to a higher value, and
         <varname>AccuracySec=1us</varname>.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><varname>Unit=</varname></term>

         <listitem><para>The unit to activate when this timer elapses.
         The argument is a unit name, whose suffix is not
         <literal>.timer</literal>. If not specified, this value
         defaults to a service that has the same name as the timer
         unit, except for the suffix. (See above.) It is recommended
         that the unit name that is activated and the unit name of the
         timer unit are named identically, except for the
         suffix.</para></listitem>
       </varlistentry>


       <varlistentry>
         <term><varname>Persistent=</varname></term>

         <listitem><para>Takes a boolean argument. If true, the time
         when the service unit was last triggered is stored on disk.
         When the timer is activated, the service unit is triggered
         immediately if it would have been triggered at least once
         during the time when the timer was inactive. This is useful to
         catch up on missed runs of the service when the machine was
         off. Note that this setting only has an effect on timers
         configured with <varname>OnCalendar=</varname>. Defaults
         to <varname>false</varname>.
         </para></listitem>
       </varlistentry>

       <varlistentry>
         <term><varname>WakeSystem=</varname></term>

         <listitem><para>Takes a boolean argument. If true, an elapsing
         timer will cause the system to resume from suspend, should it
         be suspended and if the system supports this. Note that this
         option will only make sure the system resumes on the
         appropriate times, it will not take care of suspending it
         again after any work that is to be done is finished. Defaults
         to <varname>false</varname>.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><varname>RemainAfterElapse=</varname></term>

         <listitem><para>Takes a boolean argument. If true, an elapsed
         timer will stay loaded, and its state remains queriable. If
         false, an elapsed timer unit that cannot elapse anymore is
         unloaded. Turning this off is particularly useful for
         transient timer units that shall disappear after they first
         elapse. Note that this setting has an effect on repeatedly
         starting a timer unit that only elapses once: if
         <varname>RemainAfterElapse=</varname> is on, it will not be
         started again, and is guaranteed to elapse only once. However,
         if <varname>RemainAfterElapse=</varname> is off, it might be
         started again if it is already elapsed, and thus be triggered
         multiple times. Defaults to
         <varname>yes</varname>.</para></listitem>
       </varlistentry>
     </variablelist>
   </refsect1>

   <refsect1>
       <title>See Also</title>
       <para>
         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
         <citerefentry><refentrytitle>systemctl</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.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
         <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
         <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
       </para>
   </refsect1>

 </refentry>
	<?xml version='1.0'?> <!--- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil --->
	<!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 Lesser General Public License as published by
	the Free Software Foundation; either version 2.1 of the License, or
	(at your option) any later version.

	systemd is distributed in the hope that it will be useful, but
	WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	-->

	<refentry id="systemd.timer">
	<refentryinfo>
	<title>systemd.timer</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.timer</refentrytitle>
	<manvolnum>5</manvolnum>
	</refmeta>

	<refnamediv>
	<refname>systemd.timer</refname>
	<refpurpose>Timer unit configuration</refpurpose>
	</refnamediv>

	<refsynopsisdiv>
	<para><filename><replaceable>timer</replaceable>.timer</filename></para>
	</refsynopsisdiv>

	<refsect1>
	<title>Description</title>

	<para>A unit configuration file whose name ends in
	<literal>.timer</literal> encodes information about a timer
	controlled and supervised by systemd, for timer-based
	activation.</para>

	<para>This man page lists the configuration options specific to
	this unit type. See
	<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
	for the common options of all unit configuration files. The common
	configuration items are configured in the generic [Unit] and
	[Install] sections. The timer specific configuration options are
	configured in the [Timer] section.</para>

	<para>For each timer file, a matching unit file must exist,
	describing the unit to activate when the timer elapses. By
	default, a service by the same name as the timer (except for the
	suffix) is activated. Example: a timer file
	<filename>foo.timer</filename> activates a matching service
	<filename>foo.service</filename>. The unit to activate may be
	controlled by <varname>Unit=</varname> (see below).</para>

	<para>Note that in case the unit to activate is already active at the time the timer elapses it is not restarted,
	but simply left running. There is no concept of spawning new service instances in this case. Due to this, services
	with <varname>RemainAfterExit=</varname> set (which stay around continuously even after the service's main process
	exited) are usually not suitable for activation via repetitive timers, as they will only be activated once, and
	then stay around forever.</para>
	</refsect1>

	<refsect1>
	<title>Automatic Dependencies</title>

	<para>Timer units automatically gain a <varname>Before=</varname>
	dependency on the service they are supposed to activate.</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>time-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>
	<title>Options</title>

	<para>Timer files must include a [Timer] section, which carries
	information about the timer it defines. The options specific to
	the [Timer] section of timer units are the following:</para>

	<variablelist class='unit-directives'>
	<varlistentry>
	<term><varname>OnActiveSec=</varname></term>
	<term><varname>OnBootSec=</varname></term>
	<term><varname>OnStartupSec=</varname></term>
	<term><varname>OnUnitActiveSec=</varname></term>
	<term><varname>OnUnitInactiveSec=</varname></term>

	<listitem><para>Defines monotonic timers relative to different
	starting points: <varname>OnActiveSec=</varname> defines a
	timer relative to the moment the timer itself is activated.
	<varname>OnBootSec=</varname> defines a timer relative to when
	the machine was booted up. <varname>OnStartupSec=</varname>
	defines a timer relative to when systemd was first started.
	<varname>OnUnitActiveSec=</varname> defines a timer relative
	to when the unit the timer is activating was last activated.
	<varname>OnUnitInactiveSec=</varname> defines a timer relative
	to when the unit the timer is activating was last
	deactivated.</para>

	<para>Multiple directives may be combined of the same and of
	different types. For example, by combining
	<varname>OnBootSec=</varname> and
	<varname>OnUnitActiveSec=</varname>, it is possible to define
	a timer that elapses in regular intervals and activates a
	specific service each time.</para>

	<para>The arguments to the directives are time spans
	configured in seconds. Example: "OnBootSec=50" means 50s after
	boot-up. The argument may also include time units. Example:
	"OnBootSec=5h 30min" means 5 hours and 30 minutes after
	boot-up. For details about the syntax of time spans, see
	<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>

	<para>If a timer configured with <varname>OnBootSec=</varname>
	or <varname>OnStartupSec=</varname> is already in the past
	when the timer unit is activated, it will immediately elapse
	and the configured unit is started. This is not the case for
	timers defined in the other directives.</para>

	<para>These are monotonic timers, independent of wall-clock
	time and timezones. If the computer is temporarily suspended,
	the monotonic clock stops too.</para>

	<para>If the empty string is assigned to any of these options,
	the list of timers is reset, and all prior assignments will
	have no effect.</para>

	<para>Note that timers do not necessarily expire at the
	precise time configured with these settings, as they are
	subject to the <varname>AccuracySec=</varname> setting
	below.</para></listitem>

	</varlistentry>

	<varlistentry>
	<term><varname>OnCalendar=</varname></term>

	<listitem><para>Defines realtime (i.e. wallclock) timers with
	calendar event expressions. See
	<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
	for more information on the syntax of calendar event
	expressions. Otherwise, the semantics are similar to
	<varname>OnActiveSec=</varname> and related settings.</para>

	<para>Note that timers do not necessarily expire at the
	precise time configured with this setting, as it is subject to
	the <varname>AccuracySec=</varname> setting
	below.</para>

	<para>May be specified more than once.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><varname>AccuracySec=</varname></term>

	<listitem><para>Specify the accuracy the timer shall elapse
	with. Defaults to 1min. The timer is scheduled to elapse
	within a time window starting with the time specified in
	<varname>OnCalendar=</varname>,
	<varname>OnActiveSec=</varname>,
	<varname>OnBootSec=</varname>,
	<varname>OnStartupSec=</varname>,
	<varname>OnUnitActiveSec=</varname> or
	<varname>OnUnitInactiveSec=</varname> and ending the time
	configured with <varname>AccuracySec=</varname> later. Within
	this time window, the expiry time will be placed at a
	host-specific, randomized, but stable position that is
	synchronized between all local timer units. This is done in
	order to optimize power consumption to suppress unnecessary
	CPU wake-ups. To get best accuracy, set this option to
	1us. Note that the timer is still subject to the timer slack
	configured via
	<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>'s
	<varname>TimerSlackNSec=</varname> setting. See
	<citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
	for details. To optimize power consumption, make sure to set
	this value as high as possible and as low as
	necessary.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><varname>RandomizedDelaySec=</varname></term>

	<listitem><para>Delay the timer by a randomly selected, evenly
	distributed amount of time between 0 and the specified time
	value. Defaults to 0, indicating that no randomized delay
	shall be applied. Each timer unit will determine this delay
	randomly each time it is started, and the delay will simply be
	added on top of the next determined elapsing time. This is
	useful to stretch dispatching of similarly configured timer
	events over a certain amount time, to avoid that they all fire
	at the same time, possibly resulting in resource
	congestion. Note the relation to
	<varname>AccuracySec=</varname> above: the latter allows the
	service manager to coalesce timer events within a specified
	time range in order to minimize wakeups, the former does the
	opposite: it stretches timer events over a time range, to make
	it unlikely that they fire simultaneously. If
	<varname>RandomizedDelaySec=</varname> and
	<varname>AccuracySec=</varname> are used in conjunction, first
	the randomized delay is added, and then the result is
	possibly further shifted to coalesce it with other timer
	events happening on the system. As mentioned above
	<varname>AccuracySec=</varname> defaults to 1min and
	<varname>RandomizedDelaySec=</varname> to 0, thus encouraging
	coalescing of timer events. In order to optimally stretch
	timer events over a certain range of time, make sure to set
	<varname>RandomizedDelaySec=</varname> to a higher value, and
	<varname>AccuracySec=1us</varname>.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><varname>Unit=</varname></term>

	<listitem><para>The unit to activate when this timer elapses.
	The argument is a unit name, whose suffix is not
	<literal>.timer</literal>. If not specified, this value
	defaults to a service that has the same name as the timer
	unit, except for the suffix. (See above.) It is recommended
	that the unit name that is activated and the unit name of the
	timer unit are named identically, except for the
	suffix.</para></listitem>
	</varlistentry>


	<varlistentry>
	<term><varname>Persistent=</varname></term>

	<listitem><para>Takes a boolean argument. If true, the time
	when the service unit was last triggered is stored on disk.
	When the timer is activated, the service unit is triggered
	immediately if it would have been triggered at least once
	during the time when the timer was inactive. This is useful to
	catch up on missed runs of the service when the machine was
	off. Note that this setting only has an effect on timers
	configured with <varname>OnCalendar=</varname>. Defaults
	to <varname>false</varname>.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><varname>WakeSystem=</varname></term>

	<listitem><para>Takes a boolean argument. If true, an elapsing
	timer will cause the system to resume from suspend, should it
	be suspended and if the system supports this. Note that this
	option will only make sure the system resumes on the
	appropriate times, it will not take care of suspending it
	again after any work that is to be done is finished. Defaults
	to <varname>false</varname>.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><varname>RemainAfterElapse=</varname></term>

	<listitem><para>Takes a boolean argument. If true, an elapsed
	timer will stay loaded, and its state remains queriable. If
	false, an elapsed timer unit that cannot elapse anymore is
	unloaded. Turning this off is particularly useful for
	transient timer units that shall disappear after they first
	elapse. Note that this setting has an effect on repeatedly
	starting a timer unit that only elapses once: if
	<varname>RemainAfterElapse=</varname> is on, it will not be
	started again, and is guaranteed to elapse only once. However,
	if <varname>RemainAfterElapse=</varname> is off, it might be
	started again if it is already elapsed, and thus be triggered
	multiple times. Defaults to
	<varname>yes</varname>.</para></listitem>
	</varlistentry>
	</variablelist>
	</refsect1>

	<refsect1>
	<title>See Also</title>
	<para>
	<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>systemctl</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.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
	</para>
	</refsect1>

	</refentry>