NetApp ONTAP 8.3 Aggregate Mirror

Aggregate Mirror:

Mirrored aggregates have two plexes (copies of their data), which use the SyncMirror functionality to duplicate the data to provide redundancy.

When SyncMirror is enabled, all the disks or array LUNs are divided into two pools, and a copy of the plex is created. The plexes are physically separated (each plex has its own RAID groups and its own pool), and the plexes are updated simultaneously. 

This provides added protection against data loss if more disks fail than the RAID level of the aggregate protects against or there is a loss of connectivity, because the unaffected plex continues to serve data while you fix the cause of the failure. After the plex that had a problem is fixed, you can resynchronize the two plexes and reestablish the mirror relationship.

Creating Syncmirror for an existing aggregate.

List the aggregate show command to ensure that aggr got mirrored.

After sync state, it creates two plexes.

To list the plex information.

Now in this example, 4 disks in plex0 and 4 disks in plex2.

Now you can add disks to a mirroed aggregate by using the following command with two options (-disk-list and -mirror-disk-list).

Now you have 12 disks and each plex added by 2 disks.