Information
chrony is a daemon which implements the Network Time Protocol (NTP) and is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on chrony can be found at: http://chrony.tuxfamily.org/. chrony can be configured to be a client and/or a server.
Notes:
If ntp or systemd-timesyncd are used, chrony should be removed and this section skipped
This recommendation only applies if chrony is in use on the system
Only one time synchronization method should be in use on the system
Rationale:
If chrony is in use on the system proper configuration is vital to ensuring time synchronization is working properly.
Solution
Remove and/or disable additional time synchronization methods:
Run the following command to remove ntp:
# apt purge ntp
Run the following command to stop and mask systemd-timesyncd:
# systemctl --now mask systemd-timesyncd
Configure chrony:
Add or edit server or pool lines to /etc/chrony/chrony.conf as appropriate:
server <remote-server>
Add or edit the user line to /etc/chrony/chrony.conf:
user _chrony