mirror of
https://git.proxmox.com/git/systemd
synced 2025-06-02 14:15:21 +00:00
195 lines
16 KiB
HTML
195 lines
16 KiB
HTML
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>systemd.timer</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><style>
|
|
a.headerlink {
|
|
color: #c60f0f;
|
|
font-size: 0.8em;
|
|
padding: 0 4px 0 4px;
|
|
text-decoration: none;
|
|
visibility: hidden;
|
|
}
|
|
|
|
a.headerlink:hover {
|
|
background-color: #c60f0f;
|
|
color: white;
|
|
}
|
|
|
|
h1:hover > a.headerlink, h2:hover > a.headerlink, h3:hover > a.headerlink, dt:hover > a.headerlink {
|
|
visibility: visible;
|
|
}
|
|
</style><a href="index.html">Index </a>·
|
|
<a href="systemd.directives.html">Directives </a>·
|
|
<a href="../python-systemd/index.html">Python </a>·
|
|
<a href="../libudev/index.html">libudev </a>·
|
|
<a href="../libudev/index.html">gudev </a><span style="float:right">systemd 215</span><hr><div class="refentry"><a name="systemd.timer"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>systemd.timer — Timer unit configuration</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><p><code class="filename"><em class="replaceable"><code>timer</code></em>.timer</code></p></div><div class="refsect1"><a name="idm214184246512"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p>A unit configuration file whose name ends in
|
|
"<code class="literal">.timer</code>" encodes information about
|
|
a timer controlled and supervised by systemd, for
|
|
timer-based activation.</p><p>This man page lists the configuration options
|
|
specific to this unit type. See
|
|
<a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>
|
|
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.</p><p>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 <code class="filename">foo.timer</code> activates a
|
|
matching service <code class="filename">foo.service</code>. The
|
|
unit to activate may be controlled by
|
|
<code class="varname">Unit=</code> (see below).</p><p>Unless <code class="varname">DefaultDependencies=</code>
|
|
is set to <code class="option">false</code>, timer units will
|
|
implicitly have dependencies of type
|
|
<code class="varname">Conflicts=</code> and
|
|
<code class="varname">Before=</code> on
|
|
<code class="filename">shutdown.target</code>. These ensure
|
|
that timer units are stopped cleanly prior to system
|
|
shutdown. Only timer units involved with early boot or
|
|
late system shutdown should disable this
|
|
option.</p></div><div class="refsect1"><a name="idm214180402560"></a><h2 id="Options">Options<a class="headerlink" title="Permalink to this headline" href="#Options">¶</a></h2><p>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:</p><div class="variablelist"><dl class="variablelist"><dt id="OnActiveSec="><span class="term"><code class="varname">OnActiveSec=</code>, </span><span class="term"><code class="varname">OnBootSec=</code>, </span><span class="term"><code class="varname">OnStartupSec=</code>, </span><span class="term"><code class="varname">OnUnitActiveSec=</code>, </span><span class="term"><code class="varname">OnUnitInactiveSec=</code></span><a class="headerlink" title="Permalink to this term" href="#OnActiveSec=">¶</a></dt><dd><p>Defines monotonic timers
|
|
relative to different starting points:
|
|
<code class="varname">OnActiveSec=</code> defines a
|
|
timer relative to the moment the timer
|
|
itself is
|
|
activated. <code class="varname">OnBootSec=</code>
|
|
defines a timer relative to when the
|
|
machine was booted
|
|
up. <code class="varname">OnStartupSec=</code>
|
|
defines a timer relative to when
|
|
systemd was first
|
|
started. <code class="varname">OnUnitActiveSec=</code>
|
|
defines a timer relative to when the
|
|
unit the timer is activating was last
|
|
activated. <code class="varname">OnUnitInactiveSec=</code>
|
|
defines a timer relative to when the
|
|
unit the timer is activating was last
|
|
deactivated.</p><p>Multiple directives may be
|
|
combined of the same and of different
|
|
types. For example, by combining
|
|
<code class="varname">OnBootSec=</code> and
|
|
<code class="varname">OnUnitActiveSec=</code>, it is
|
|
possible to define a timer that
|
|
elapses in regular intervals and
|
|
activates a specific service each
|
|
time.</p><p>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
|
|
<a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>.</p><p>If a timer configured with
|
|
<code class="varname">OnBootSec=</code> or
|
|
<code class="varname">OnStartupSec=</code> 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.</p><p>These are monotonic timers,
|
|
independent of wall-clock time and timezones. If the
|
|
computer is temporarily suspended, the
|
|
monotonic clock stops too.</p><p>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.</p><p>Note that timers do not
|
|
necessarily expire at the precise
|
|
time configured with these settings,
|
|
as they are subject to the
|
|
<code class="varname">AccuracySec=</code>
|
|
setting below.</p></dd><dt id="OnCalendar="><span class="term"><code class="varname">OnCalendar=</code></span><a class="headerlink" title="Permalink to this term" href="#OnCalendar=">¶</a></dt><dd><p>Defines realtime
|
|
(i.e. wallclock) timers with calendar
|
|
event expressions. See
|
|
<a href="systemd.time.html"><span class="citerefentry"><span class="refentrytitle">systemd.time</span>(7)</span></a>
|
|
for more information on the syntax of
|
|
calendar event expressions. Otherwise,
|
|
the semantics are similar to
|
|
<code class="varname">OnActiveSec=</code> and
|
|
related settings.</p><p>Note that timers do not
|
|
necessarily expire at the precise
|
|
time configured with this setting,
|
|
as it is subject to the
|
|
<code class="varname">AccuracySec=</code>
|
|
setting below.</p></dd><dt id="AccuracySec="><span class="term"><code class="varname">AccuracySec=</code></span><a class="headerlink" title="Permalink to this term" href="#AccuracySec=">¶</a></dt><dd><p>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
|
|
<code class="varname">OnCalendar=</code>,
|
|
<code class="varname">OnActiveSec=</code>,
|
|
<code class="varname">OnBootSec=</code>,
|
|
<code class="varname">OnStartupSec=</code>,
|
|
<code class="varname">OnUnitActiveSec=</code> or
|
|
<code class="varname">OnUnitInactiveSec=</code>
|
|
and ending the time configured with
|
|
<code class="varname">AccuracySec=</code>
|
|
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 distribute the wake-up time
|
|
in networked installations, as well as
|
|
optimizing 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
|
|
<a href="systemd-system.conf.html"><span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span></a>'s
|
|
<code class="varname">TimerSlackNSec=</code>
|
|
setting. See
|
|
<a href="prctl.html"><span class="citerefentry"><span class="refentrytitle">prctl</span>(2)</span></a>
|
|
for details. To optimize power
|
|
consumption, make sure to set this
|
|
value as high as possible and as low
|
|
as necessary.</p></dd><dt id="Unit="><span class="term"><code class="varname">Unit=</code></span><a class="headerlink" title="Permalink to this term" href="#Unit=">¶</a></dt><dd><p>The unit to activate
|
|
when this timer elapses. The argument is a
|
|
unit name, whose suffix is not
|
|
"<code class="literal">.timer</code>". 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.</p></dd><dt id="Persistent="><span class="term"><code class="varname">Persistent=</code></span><a class="headerlink" title="Permalink to this term" href="#Persistent=">¶</a></dt><dd><p>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 <code class="varname">OnCalendar=</code>.
|
|
</p></dd><dt id="WakeSystem="><span class="term"><code class="varname">WakeSystem=</code></span><a class="headerlink" title="Permalink to this term" href="#WakeSystem=">¶</a></dt><dd><p>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
|
|
<code class="varname">false</code>.</p></dd></dl></div></div><div class="refsect1"><a name="idm214184333120"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
|
|
<a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
|
|
<a href="systemctl.html"><span class="citerefentry"><span class="refentrytitle">systemctl</span>(8)</span></a>,
|
|
<a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>,
|
|
<a href="systemd.service.html"><span class="citerefentry"><span class="refentrytitle">systemd.service</span>(5)</span></a>,
|
|
<a href="systemd.time.html"><span class="citerefentry"><span class="refentrytitle">systemd.time</span>(7)</span></a>,
|
|
<a href="systemd.directives.html"><span class="citerefentry"><span class="refentrytitle">systemd.directives</span>(7)</span></a>,
|
|
<a href="systemd-system.conf.html"><span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span></a>,
|
|
<a href="prctl.html"><span class="citerefentry"><span class="refentrytitle">prctl</span>(2)</span></a>
|
|
</p></div></div></body></html>
|