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systemd-stable/man/systemd-time-wait-sync.service.xml
Lennart Poettering b149d230ea man: extend time-{set,sync}.target + systemd-timesyncd/wait-sync docs
Let's link the three man pages together more tightly and explain what
the two targets are about, emphasizing local/quick/reliable/approximate
vs remote/slow/unreliable/accurate synchronization.

Follow-up for: 1431b2f701 fe934b42e4
2020-12-28 10:52:33 +01:00

71 lines
2.6 KiB
XML

<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="systemd-time-wait-sync.service" conditional='ENABLE_TIMESYNCD'>
<refentryinfo>
<title>systemd-time-wait-sync.service</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>systemd-time-wait-sync.service</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-time-wait-sync.service</refname>
<refname>systemd-time-wait-sync</refname>
<refpurpose>Wait until kernel time is synchronized</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>systemd-time-wait-sync.service</filename></para>
<para><filename>/usr/lib/systemd/systemd-time-wait-sync</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><filename>systemd-time-wait-sync</filename> is a system service that delays the start of units that
are ordered after <filename>time-sync.target</filename> (see
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> for
details) until the system time has been synchronized with an accurate remote reference time source by
<filename>systemd-timesyncd.service</filename>.</para>
<para><filename>systemd-timesyncd.service</filename> notifies <filename>systemd-time-wait-sync</filename>
about successful synchronization. <filename>systemd-time-wait-sync</filename> also tries to detect when
the kernel marks the system clock as synchronized, but this detection is not reliable and is intended
only as a fallback for compatibility with alternative NTP services that can be used to synchronize time
(e.g., ntpd, chronyd).</para>
</refsect1>
<refsect1>
<title>Files</title>
<variablelist>
<varlistentry>
<term><filename>/run/systemd/timesync/synchronized</filename></term>
<listitem>
<para>The presence of this file indicates to this service that the system clock has been synchronized.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-timesyncd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
</para>
</refsect1>
</refentry>