Geographic mirroring is a function that keeps two identical copies of an independent disk pool at two sites to provide high availability and disaster recovery. The copy owned by the primary node is the production copy and the copy owned by a backup node at the other site is the mirror copy. User operations and applications access the independent disk pool on the primary node, the node that owns the production copy.
Geographic mirroring is a subfunction of cross-site mirroring (XSM), which is part of i5/OS™ Option 41, High Available Switchable Resources.