mirror of
https://github.com/systemd/systemd-stable.git
synced 2024-12-23 17:34:00 +03:00
131 lines
6.3 KiB
XML
131 lines
6.3 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="timesyncd.conf" conditional='ENABLE_TIMESYNCD'
|
||
xmlns:xi="http://www.w3.org/2001/XInclude">
|
||
<refentryinfo>
|
||
<title>timesyncd.conf</title>
|
||
<productname>systemd</productname>
|
||
</refentryinfo>
|
||
|
||
<refmeta>
|
||
<refentrytitle>timesyncd.conf</refentrytitle>
|
||
<manvolnum>5</manvolnum>
|
||
</refmeta>
|
||
|
||
<refnamediv>
|
||
<refname>timesyncd.conf</refname>
|
||
<refname>timesyncd.conf.d</refname>
|
||
<refpurpose>Network Time Synchronization configuration files</refpurpose>
|
||
</refnamediv>
|
||
|
||
<refsynopsisdiv>
|
||
<para><filename>/etc/systemd/timesyncd.conf</filename></para>
|
||
<para><filename>/etc/systemd/timesyncd.conf.d/*.conf</filename></para>
|
||
<para><filename>/run/systemd/timesyncd.conf.d/*.conf</filename></para>
|
||
<para><filename>/usr/lib/systemd/timesyncd.conf.d/*.conf</filename></para>
|
||
</refsynopsisdiv>
|
||
|
||
<refsect1>
|
||
<title>Description</title>
|
||
|
||
<para>These configuration files control NTP network time synchronization. See
|
||
<citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>7</manvolnum></citerefentry>
|
||
for a general description of the syntax.</para>
|
||
</refsect1>
|
||
|
||
<xi:include href="standard-conf.xml" xpointer="main-conf" />
|
||
|
||
<refsect1>
|
||
<title>Options</title>
|
||
|
||
<para>The following settings are configured in the [Time] section:</para>
|
||
|
||
<variablelist class='network-directives'>
|
||
|
||
<varlistentry>
|
||
<term><varname>NTP=</varname></term>
|
||
<listitem><para>A space-separated list of NTP server host names or IP addresses. During runtime this
|
||
list is combined with any per-interface NTP servers acquired from
|
||
<citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
|
||
<command>systemd-timesyncd</command> will contact all configured system or per-interface servers in
|
||
turn, until one responds. When the empty string is assigned, the list of NTP servers is reset, and
|
||
all prior assignments will have no effect. This setting defaults to an empty list.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>FallbackNTP=</varname></term>
|
||
<listitem><para>A space-separated list of NTP server host names or IP addresses to be used as the
|
||
fallback NTP servers. Any per-interface NTP servers obtained from
|
||
<citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||
take precedence over this setting, as do any servers set via <varname>NTP=</varname> above. This
|
||
setting is hence only relevant if no other NTP server information is known. When the empty string is
|
||
assigned, the list of NTP servers is reset, and all prior assignments will have no effect. If this
|
||
option is not given, a compiled-in list of NTP servers is used.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>RootDistanceMaxSec=</varname></term>
|
||
<listitem><para>Maximum acceptable root distance, i.e. the maximum estimated time required for a
|
||
packet to travel to the server we are connected to from the server with the reference clock. If
|
||
the current server does not satisfy this limit, <command>systemd-timesyncd</command> will switch
|
||
to a different server.</para>
|
||
|
||
<para>Takes a time span value. The default unit is seconds, but other units may be specified, see
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||
Defaults to 5 seconds.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>PollIntervalMinSec=</varname></term>
|
||
<term><varname>PollIntervalMaxSec=</varname></term>
|
||
<listitem><para>The minimum and maximum poll intervals for NTP messages. Polling starts at the
|
||
minimum poll interval, and is adjusted within the specified limits in response to received packets.
|
||
</para>
|
||
|
||
<para>Each setting takes a time span value. The default unit is seconds, but other units may be
|
||
specified, see
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||
<varname>PollIntervalMinSec=</varname> defaults to 32 seconds and must not be smaller than
|
||
16 seconds. <varname>PollIntervalMaxSec=</varname> defaults to 34 min 8 s (2048 seconds) and must be
|
||
larger than <varname>PollIntervalMinSec=</varname>.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>ConnectionRetrySec=</varname></term>
|
||
<listitem><para>Specifies the minimum delay before subsequent attempts to contact a new NTP server
|
||
are made.</para>
|
||
|
||
<para>Takes a time span value. The default unit is seconds, but other units may be specified, see
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||
Defaults to 30 seconds and must not be smaller than 1 second.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>SaveIntervalSec=</varname></term>
|
||
<listitem><para>The interval at which the current time is periodically saved to disk, in the absence
|
||
of any recent synchronisation from an NTP server. This is especially useful for offline systems
|
||
with no local RTC, as it will guarantee that the system clock remains roughly monotonic across
|
||
reboots.</para>
|
||
|
||
<para>Takes a time interval value. The default unit is seconds, but other units may be specified, see
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
|
||
Defaults to 60 seconds.</para></listitem>
|
||
</varlistentry>
|
||
|
||
</variablelist>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>See Also</title>
|
||
<para>
|
||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd-timesyncd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||
</para>
|
||
</refsect1>
|
||
|
||
</refentry>
|