Patent ID: 7739454

Claim:
A storage subsystem, comprising: a plurality of channel adapters that each controls the exchange of data with a host device; a plurality of storage device groups that each provides a logical storage region; a plurality of disk adapters that each controls the exchange of data with each of the storage device groups; a cache memory that is used by each of the channel adapters and each of the disk adapters; a plurality of cache partition regions constituted by logically partitioning the cache memory; and a control memory that stores management information for managing each of the cache partition regions, wherein the management information is constituted by both a plurality of partition management information that is used to independently manage corresponding ones of the cache partition regions, and common management information that is used to commonly manage a plurality of the cache partition regions, wherein when a cache partition region corresponding to a certain logical storage region is transferred from a first cache partition region to a second cache partition region, information in relation to a queue and counter included in the management information stored in the control memory is updated, wherein the management information is constituted by sub-management information of a plurality of types, and wherein the partition management information are constituted by partitioning, based on an indication of a kind of status in which data is stored in an area of the cache partition region, some of the sub-management information items for each of the cache partition regions, the remainder of the sub-management information being used as the common management information.