An administrator has implemented automatic switchover (ASO) with Peer Persistence on a pair of HPE...

HPE Peer Persistence for the Alletra 6000 (and Nimble) provides synchronous replication and automatic transparent failover (ATF) using the Automatic Switchover (ASO) feature. This process is governed by a Quorum Witness that monitors the health of both arrays in a group.

A fundamental design principle of HPE high-availability storage is to prevent "flapping"—a condition where a workload repeatedly bounces between two sites due to an unstable connection. Consequently, the ASO process is designed to be unidirectional and sticky. When a primary site failure occurs and the Quorum Witness authorizes an automatic switchover, the secondary array becomes the "Upstream" (active) array and begins serving I/O. Once the original primary site is restored and the replication link is re-established, the arrays will automatically begin a resynchronization to ensure data consistency. However, even after the data is fully synced, the system will not automatically move the workload back to the original array. The administrator must perform a manual handover to return the volume collection to its preferred primary site.

Regarding the other options:

Option B: If the witness is unreachable, ASO is automatically disabled to prevent a "split-brain" scenario where both arrays might try to become active simultaneously.

Option C: A single controller failure within an Alletra 6000 does not trigger an ASO. Instead, the array performs an internal controller failover (ALUA) which is transparent to the Peer Persistence relationship.

Option D: In a synchronous relationship, if the target becomes unavailable, the source array typically transitions to an "Out of Sync" state but continues to serve host I/O in order to maintain application availability, rather than rejecting it.