Hi,
After an "apt upgrade" and reboot I got in cehp "cluster [WRN] 1 clock skew 0.131975s > max 0.05s". Indeed after 2 minutes the error dissapear from ceph dashboard.
Reading more I found:
systemd-timesyncd does no clock discipline: the clock is not trained or compensated, and internal clock drift over time is not reduced. It has rudimentary logic to adjust poll interval but without disciplining the host will end up with uneven time forever as systemd-timesyncd pushes or pulls at whatever interval it thinks the near-term drift requires. It also can't assess the quality of the remote time source. You're unlikely to get accuracy much greater than 100ms. This is sufficient for simple end user devices like laptops, but it could definitely cause problems for distributed systems that want greater time precision.
And systemd-timesyncd seems to do the corrections with time steps and not by skewing time.
Would it be an idea to replace systemd-timesyncd with ntpd in proxmox?
Regards,
Rares
After an "apt upgrade" and reboot I got in cehp "cluster [WRN] 1 clock skew 0.131975s > max 0.05s". Indeed after 2 minutes the error dissapear from ceph dashboard.
Reading more I found:
systemd-timesyncd does no clock discipline: the clock is not trained or compensated, and internal clock drift over time is not reduced. It has rudimentary logic to adjust poll interval but without disciplining the host will end up with uneven time forever as systemd-timesyncd pushes or pulls at whatever interval it thinks the near-term drift requires. It also can't assess the quality of the remote time source. You're unlikely to get accuracy much greater than 100ms. This is sufficient for simple end user devices like laptops, but it could definitely cause problems for distributed systems that want greater time precision.
And systemd-timesyncd seems to do the corrections with time steps and not by skewing time.
Would it be an idea to replace systemd-timesyncd with ntpd in proxmox?
Regards,
Rares
