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Ubuntu uses timedatectl
and timesyncd
for synchronising time, and they are installed by default as part of systemd
. You can optionally use chrony
to serve the Network Time Protocol.
In this guide, we will show you how to configure these services.
Note:
Ifchrony
is installed,timedatectl
steps back to letchrony
handle timekeeping. This ensures that no two time-syncing services will be in conflict.
Check status of timedatectl
The current status of time and time configuration via timedatectl
and timesyncd
can be checked with the timedatectl status
command, which will produce output like this:
Local time: Wed 2023-06-14 12:05:11 BST
Universal time: Wed 2023-06-14 11:05:11 UTC
RTC time: Wed 2023-06-14 11:05:11
Time zone: Europe/Isle_of_Man (BST, +0100)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no
If chrony
is running, it will automatically switch to:
[...]
systemd-timesyncd.service active: no
Configure timedatectl
By using timedatectl
, an admin can control the timezone, how the system clock should relate to the hwclock
and whether permanent synchronisation should be enabled. See man timedatectl
for more details.
Check status of timesyncd
timesyncd
itself is a normal service, so you can check its status in more detail using:
systemctl status systemd-timesyncd
The output produced will look something like this:
systemd-timesyncd.service - Network Time Synchronization
Loaded: loaded (/lib/systemd/system/systemd-timesyncd.service; enabled; vendor preset: enabled)
Active: active (running) since Fri 2018-02-23 08:55:46 UTC; 10s ago
Docs: man:systemd-timesyncd.service(8)
Main PID: 3744 (systemd-timesyn)
Status: "Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com)."
Tasks: 2 (limit: 4915)
CGroup: /system.slice/systemd-timesyncd.service
|-3744 /lib/systemd/systemd-timesyncd
Feb 23 08:55:46 bionic-test systemd[1]: Starting Network Time Synchronization...
Feb 23 08:55:46 bionic-test systemd[1]: Started Network Time Synchronization.
Feb 23 08:55:46 bionic-test systemd-timesyncd[3744]: Synchronized to time server 91.189.89.198:123 (ntp.ubuntu.com).
Configure timesyncd
The server from which to fetch time for timedatectl
and timesyncd
can be specified in /etc/systemd/timesyncd.conf
. Additional config files can be stored in /etc/systemd/timesyncd.conf.d/
. The entries for NTP=
and FallbackNTP=
are space-separated lists. See man timesyncd.conf
for more details.
Next steps
If you would now like to serve the Network Time Protocol via chrony
, this guide will walk you through how to install and configure your setup.
References
-
See the Ubuntu Time wiki page for more information.