How disks are assigned to plexes

You need to understand how Data ONTAP assigns disks to plexes in order to configure your disk shelves and host adapters.

When a mirrored aggregate is created, Data ONTAP uses spare disks from a collection of disks, to create two disk pools, pool0 and pool1.

When assigning a disk to a pool, Data ONTAP determines the shelf for the disk and ensures that the disks in pool0 are from different shelves than the disks in pool1. So, before enabling SyncMirror, you should ensure that the disks are installed in at least two shelves and the shelves are connected to the system with separate cables and adapters. Disk pools must be physically separate to ensure high availability of the mirrored aggregate.

Disks from pool0 are used to create plex0 while disks from pool1 are used to create plex1.

Plexes local to the host node in an HA pair must be connected to the disk pool named pool0. pool0 consists of the storage attached to host adapters in slots 3 through 7.

Note: Pool rules for MetroCluster configurations that use switches are different.

For more information about storage system slot assignments, see the System Configuration Guide.