3.4. Time Synchronization

The Proxmox VE cluster stack itself relies heavily on the fact that all the nodes have precisely synchronized time. Some other components, like Ceph, also won’t work properly if the local time on all nodes is not in sync.

Time synchronization between nodes can be achieved using the “Network Time Protocol” (NTP). As of Proxmox VE 7, chrony is used as the default NTP daemon, while Proxmox VE 6 uses systemd-timesyncd. Both come preconfigured to use a set of public servers.

Important

If you upgrade your system to Proxmox VE 7, it is recommended that you manually install either chrony, ntp or openntpd.

In some cases, it might be desired to use non-default NTP servers. For example, if your Proxmox VE nodes do not have access to the public internet due to restrictive firewall rules, you need to set up local NTP servers and tell the NTP daemon to use them.