Which SnapMirror policy provides the most granular historical restore options?

The vault SnapMirror policy is specifically designed for long-term retention and archival. It replicates a history of snapshots from the source volume to the destination, based on rules defined in the policy (e.g., keep 30 daily, 12 monthly). This creates multiple, distinct points in time on the destination volume. Consequently, it offers the most granular options for restoring data from various historical points, which is ideal for backup and compliance purposes. Other policies are designed for disaster recovery with fewer recovery points.

B. mirror-latest replicates only the most recent snapshot, providing a single recovery point for disaster recovery, not historical granularity.

C. sync (SnapMirror Synchronous) maintains a real-time mirror with a zero Recovery Point Objective (RPO), offering no historical snapshot retention.

D. replica is a general term for a copy of data and not a specific, pre-defined SnapMirror policy type in ONTAP.

1. NetApp. (2023). TR-4015: ONTAP Data Protection Power Guide. Section: "SnapMirror policy types," pp. 12-13. This document explicitly states, "A vault policy is used to create a remote backup copy of the source volume for long-term retention."

2. NetApp. (2023). ONTAP 9 Data protection administration guide. Section: "SnapMirror policy types". This guide details that the vault policy type is used to transfer a specified set of Snapshot copies for archival purposes.