Patent ID: 8661212

Claim:
A storage system to which a storage system ID is allocated, the storage system ID being used for recognition of the storage system by external devices including external storage systems and management computers connected thereto, comprising: a cache memory; disk drives for providing a plurality of logical volumes each of which a logical volume ID is allocated to; and a processor being configured to logically divide the storage system into a plurality of logical storage systems to provide the logical storage systems to a host computer, and allocate at least one of the logical volumes, and a partitioned cache memory of the cache memory to each of the logical storage systems, logical storage system IDs being assigned to their respective logical storage systems, one of the logical storage system IDs being the same as the storage system ID; a memory, for storing the storage system ID, the logical storage system IDs and logical volume IDs, one of the logical storage system IDs being same as the storage system ID; and an interface coupled to the external devices, for communicating to each of the external devices; wherein in a case of receiving a reference indication inquiry from one of the management computers that is unable to recognize the logical storage systems, the processor is configured to report only the one of logical storage system IDs being the same as the storage system ID, which is recognized by the management computers, wherein in a case of communicating with one of the external storage systems that is unable to recognize the logical storage systems, the processor is configured to make the logical storage system to which the storage system ID is allocated operate for the communication by reporting only the one of logical storage system IDs being the same as the storage system ID, because the storage system ID is recognized by the external storage system.