systemd-timesyncd.service.xml revision 681eb9cf2b831293a4f3d4c48a748d2e4a25d69e
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This file is part of systemd.
Copyright 2014 Kay Sievers
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<refentry id="systemd-timesyncd.service" conditional='ENABLE_TIMESYNCD'>
<refentryinfo>
<title>systemd-timesyncd.service</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Kay</firstname>
<surname>Sievers</surname>
<email>kay@vrfy.org</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>systemd-timesyncd.service</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-timesyncd.service</refname>
<refname>systemd-timesyncd</refname>
<refpurpose>Network Time Synchronization</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>systemd-timesyncd.service</filename></para>
<para><filename>&rootlibexecdir;/systemd-timesyncd</filename></para>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><filename>systemd-timesyncd</filename> is a system service
that may be used to synchronize the local system clock with a
remote Network Time Protocol server. It also saves the local time
to disk every time the clock has been synchronized and uses this
to possibly advance the system realtime clock on subsequent
reboots to ensure it monotonically advances even if the system
lacks a battery-buffered RTC chip.</para>
<para>The NTP servers contacted are determined from the global
settings in
<citerefentry><refentrytitle>timesyncd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
the per-link static settings in <filename>.network</filename>
files, and the per-link dynamic settings received over DHCP. See
<citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
for more details.</para>
</refsect1>
<refsect1>
<title>Files</title>
<variablelist>
<varlistentry>
<term><filename>/var/lib/systemd/clock</filename></term>
<listitem>
<para>This file contains the timestamp of last successful
synchronization.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>timesyncd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>timedatectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry project='man-pages'><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>