What is the main function of MetroCluster healing?

The main function of MetroCluster healing is to prepare the aggregates at the disaster site for resynchronization after that site has recovered and is ready to rejoin the MetroCluster. Following a switchover, the aggregates on the formerly active site are out of sync. The healing process brings these aggregates online and establishes them as the target for a SnapMirror relationship, allowing the system to resynchronize only the changed data from the surviving site, thereby restoring the mirrored, redundant state efficiently.

B. Compressing storage volumes is a storage efficiency feature and is entirely unrelated to the disaster recovery and resynchronization process of MetroCluster healing.

C. Deleting unused disks is a storage provisioning task. The healing process is focused on restoring data redundancy, not managing physical disk inventory.

D. Restarting cluster nodes may be part of a site recovery, but the specific "healing" phase refers to the data resynchronization process, not the hardware reboot.

1. NetApp, Inc. (2023). MetroCluster Management and Disaster Recovery Guide for ONTAP 9.12.1. NetApp Documentation. Section: "Overview of the switchback operation". It states, "The switchback operation consists of two phases: a healing phase and a resynchronization phase... During the healing phase, the aggregates on the disaster site are brought online..."

2. NetApp, Inc. (2023). TR-4689: MetroCluster Best Practices. NetApp Technical Report. Section 5, "Disaster Recovery," describes the switchback process, which includes healing as the first step to prepare for resynchronization.