man/systemd-time-wait-sync.service.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   Copyright © 2018 Peter A. Bigot
   9 -->
  10
  11 <refentry id="systemd-time-wait-sync.service" conditional='ENABLE_TIMESYNCD'>
  12
  13   <refentryinfo>
  14     <title>systemd-time-wait-sync.service</title>
  15     <productname>systemd</productname>
  16   </refentryinfo>
  17
  18   <refmeta>
  19     <refentrytitle>systemd-time-wait-sync.service</refentrytitle>
  20     <manvolnum>8</manvolnum>
  21   </refmeta>
  22
  23   <refnamediv>
  24     <refname>systemd-time-wait-sync.service</refname>
  25     <refname>systemd-time-wait-sync</refname>
  26     <refpurpose>Wait Until Kernel Time Synchronized</refpurpose>
  27   </refnamediv>
  28
  29   <refsynopsisdiv>
  30     <para><filename>systemd-time-wait-sync.service</filename></para>
  31     <para><filename>/usr/lib/systemd/systemd-time-wait-sync</filename></para>
  32   </refsynopsisdiv>
  33
  34   <refsect1>
  35     <title>Description</title>
  36
  37     <para><filename>systemd-time-wait-sync</filename> is a system service that delays the start of units that depend on
  38     <filename>time-sync.target</filename> until the system time has been synchronized with an accurate time source by
  39     <filename>systemd-timesyncd.service</filename>.</para>
  40
  41     <para><filename>systemd-timesyncd.service</filename> notifies on successful synchronization.
  42     <filename>systemd-time-wait-sync</filename> also tries to detect when the kernel marks the time as synchronized,
  43     but this detection is not reliable and is intended only as a fallback for other servies that can be used to
  44     synchronize time (e.g., ntpd, chronyd).</para>
  45
  46   </refsect1>
  47
  48   <refsect1>
  49     <title>Files</title>
  50
  51     <variablelist>
  52       <varlistentry>
  53         <term><filename>/run/systemd/timesync/synchronized</filename></term>
  54
  55         <listitem>
  56           <para>The presence of this file indicates to this service that the system clock has been synchronized.</para>
  57         </listitem>
  58
  59       </varlistentry>
  60     </variablelist>
  61
  62   </refsect1>
  63
  64   <refsect1>
  65     <title>See Also</title>
  66     <para>
  67       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
  68       <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
  69       <citerefentry><refentrytitle>systemd-timesyncd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
  70     </para>
  71   </refsect1>
  72
  73 </refentry>