Which SnapMirror relationship type is primarily used for long-term backup retention?

The vault relationship type, also known as SnapVault, is NetApp's disk-to-disk backup solution. Its primary purpose is the long-term retention of point-in-time Snapshot copies on secondary storage. It allows for a different, typically longer, retention schedule on the backup site than on the primary site, optimizing storage for archival and compliance purposes.

B. mirror-latest is for disaster recovery (DR), keeping only the newest data version, which is the opposite of long-term retention.

C. sync is for zero RPO disaster recovery, providing real-time data replication, not for creating a long-term backup archive.

D. mirror-all-snapshots is a DR policy for a complete mirror, not specifically optimized for the space efficiency and distinct retention schedules of long-term backup.

1. NetApp, Inc. (2020). TR-4015: SnapMirror Configuration and Best Practices Guide for ONTAP 9.8. Section 1, "Introduction," p. 7. "SnapVault is NetApp’s disk-to-disk backup feature that creates point-in-time Snapshot copies of a source system on a destination system... SnapVault is ideal for long-term data retention."

2. NetApp ONTAP 9 Documentation Center. (2022). Data protection overview. Section: "SnapVault backups for long-term retention". "You can use SnapVault backup to protect your data for long-term retention."