Out-of-Sync Volumes

A volume collection is in-sync only if all upstream volumes in the volume collection are in-sync.

If the replication link breaks, after about 30 seconds, the volume collections transition to an out-of-sync state, and writes are accepted without being replicated. When the link is restored, the system performs a resynchronization and the volume collections transition to an in-sync state with all incoming writes written to both arrays before acknowledging the hosts.

NOTE: If you add a volume to a synchronously-replicated volume collection, all the volumes that are configured for synchronous replication will go out-of-sync until the newly added volume is in-sync.

Snapshots taken while the volume collection is out-of-sync are not replicated and the snapshots will only be created on the upstream volumes.

It is not possible to catch-up or replicate any snapshots that were missed while the volume was out-of-sync.

When the volume is out-of-sync, the Recovery Point Objective (RPO) is not zero. The volume might be out-of-sync due to a variety of reasons such as a resynchronization that is in progress, I/O might have been paused, the user editing the volume collection, or some other reason.