Time synchronization

Ceph daemons pass critical messages to each other, which must be processed before daemons reach a timeout threshold. If the clocks in Ceph monitors are not synchronized, it can lead to a number of anomalies.

For example:

• Daemons ignoring received messages such as outdated timestamps.

• Timeouts triggered too soon or late when a message was not received in time.

Clock drift may still be noticeable with NTP even though the discrepancy is not yet harmful. Ceph clock drift and clock skew warnings can get triggered even though NTP maintains a reasonable level of synchronization. Increasing your clock drift may be tolerable under such circumstances. However, a number of factors such as workload, network latency, configuring overrides to default timeouts, and other synchronization options can influence the level of acceptable clock drift without compromising Paxos guarantees.