To achieve zero RPO across low-latency links, which replication mode is appropriate?

• A. SnapMirror Asynchronous
• B. MetroCluster
• C. FlexCache
• D. SnapMirror Synchronous

Answer: (D)

Zero RPO means no data loss on failover, which happens when every write is committed at both sites before the operation is considered complete. SnapMirror Synchronous provides this by mirroring each write across the link and only acknowledging the write once the remote copy confirms it. Under low-latency connections, this ensures the secondary is always up to date, so a failover preserves all recent data.

SnapMirror Asynchronous would not guarantee zero RPO because writes can be acknowledged on the primary before they are replicated, risking data loss if a failover occurs. FlexCache isn’t about replication mode; it’s a caching feature that speeds access rather than ensuring zero RPO. MetroCluster is a full DR solution that can use synchronous replication, but the specific mode that guarantees zero RPO on a live link is SnapMirror Synchronous.