Patent ID: 7441095

Claim:
A system having a first controller of a virtualization system and a second controller of a disk array system, said second controller being coupled to said first controller, said system performing data processing according to a request from a host device, wherein said first controller conducts mapping such that relations between at least one first logical unit accessed by said host device and at least one intermediate logical device are set, wherein said intermediate logical device is related to a second logical unit of said second controller by a virtualization setting function of said first controller, wherein said first logical unit is related to a first logical unit number (LUN), wherein said second logical unit is related to a second LUN, wherein said first and second LUNs are different from each other and become related according to the mapping, and wherein said first controller obtains oath information indicating a path from said first LUN to said second LUN via said intermediate logical device, and recognizes a memory device as a same memory device if a plurality of paths from said first LUN to a plurality of said second logical units are connected to said memory device.