Assigned disks and array LUNs are associated with a pool, either pool0 or pool1. Keeping all disks on a loop or stack in the same pool ensures redundancy and supports automatic disk assignment.
Typically, pool0 is assigned to the local pool and pool1 is assigned to the remote pool.
On storage system models that only support one loop or stack, you can configure your system to have both pools on a single loop or stack. Automatic assignment at the stack or loop level does not work, but automatic assignment at the shelf level works for this configuration.
For more information about configuring SyncMirror with disks or array LUNs, see the Data ONTAP Data Protection Tape Backup and Recovery Guide for 7-Mode.