Understanding mirrored HA pairs
Mirrored HA pairs provide high availability through failover, just as standard HA pairs do. Additionally, mirrored HA pairs maintain two complete copies of all mirrored data. These copies are called plexes and are continually and synchronously updated every time Data ONTAP writes to a mirrored aggregate. The plexes can be physically separated to protect against the loss of one set of disks or array LUNs.
Mirrored HA pairs use SyncMirror. For more information about SyncMirror, see the Data ONTAP Data Protection Online Backup and Recovery Guide for 7-Mode.