Patent ID: 8713577

Claim:
A storage apparatus which is connected via a network to a host apparatus which requests data I/Os, the storage apparatus comprising: a plurality of microprocessors; a plurality of storage areas formed in a drive group configured from a plurality of physical drives; and a management unit which manages, as the microprocessors which possess ownership to the storage areas, the microprocessors which handle data I/Os to/from one or more storage areas among the plurality of storage areas, wherein the management unit detects variations in processing loads of the plurality of microprocessors, generates, on the basis of variations in a processing load, load balancing target information which includes information on the storage areas to which the ownership is migrated, information on a migration-source microprocessor serving as the migration source of the ownership, and information on a migration-destination microprocessor serving as the migration destination of the ownership, and migrates the ownership to the storage areas with timing such that there is no drop in the processing load of the migration-destination microprocessor contained in the load balancing target information.