a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
12b42c76672a66c2d4ea7212c14f8f1b5a62b78dTom Gundersen "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers This file is part of systemd.
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers Copyright 2014 Kay Sievers
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers systemd is free software; you can redistribute it and/or modify it
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers under the terms of the GNU Lesser General Public License as published by
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers the Free Software Foundation; either version 2.1 of the License, or
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers (at your option) any later version.
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers systemd is distributed in the hope that it will be useful, but
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers WITHOUT ANY WARRANTY; without even the implied warranty of
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers Lesser General Public License for more details.
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers You should have received a copy of the GNU Lesser General Public License
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers along with systemd; If not, see <http://www.gnu.org/licenses/>.
a91df40e69fec72cc98c9829721fa5153da28bc2Kay Sievers<refentry id="systemd-timesyncd.service" conditional='ENABLE_TIMESYNCD'>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <title>systemd-timesyncd.service</title>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <productname>systemd</productname>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <refentrytitle>systemd-timesyncd.service</refentrytitle>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <refname>systemd-timesyncd.service</refname>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <refname>systemd-timesyncd</refname>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <refpurpose>Network Time Synchronization</refpurpose>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <refsynopsisdiv>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <para><filename>systemd-timesyncd.service</filename></para>
12b42c76672a66c2d4ea7212c14f8f1b5a62b78dTom Gundersen <para><filename>/usr/lib/systemd/systemd-timesyncd</filename></para>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek </refsynopsisdiv>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <para><filename>systemd-timesyncd</filename> is a system service
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek that may be used to synchronize the local system clock with a
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek remote Network Time Protocol server. It also saves the local time
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek to disk every time the clock has been synchronized and uses this
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek to possibly advance the system realtime clock on subsequent
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek reboots to ensure it monotonically advances even if the system
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek lacks a battery-buffered RTC chip.</para>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <para>The NTP servers contacted are determined from the global
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>timesyncd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek the per-link static settings in <filename>.network</filename>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek files, and the per-link dynamic settings received over DHCP. See
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek for more details.</para>
8731be1a529272e8010505627316161adb476842Lennart Poettering <para><citerefentry><refentrytitle>timedatectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
8731be1a529272e8010505627316161adb476842Lennart Poettering <command>set-ntp</command> command may be used to enable and
8731be1a529272e8010505627316161adb476842Lennart Poettering start, or disable and stop this service.</para>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <term><filename>/var/lib/systemd/clock</filename></term>
a8eaaee72a2f06e0fb64fb71de3b71ecba31dafbJan Engelhardt <para>This file contains the timestamp of the last successful
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek synchronization.</para>
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>timesyncd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.network</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>timedatectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>localtime</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
798d3a524ea57aaf40cb53858aaa45ec702f012dZbigniew Jędrzejewski-Szmek <citerefentry project='man-pages'><refentrytitle>hwclock</refentrytitle><manvolnum>8</manvolnum></citerefentry>