Patent ID: 8103828

Claim:
A storage system comprising: an internal storage apparatus that is connected to a host apparatus and includes a first controller equipped with a first channel interface, and a plurality of first disk devices constituting a plurality of internal logical devices; and an external storage apparatus that is connected to the internal storage apparatus and includes a second controller equipped with a second channel interface, and a plurality of second disk devices constituting a plurality of external logical devices virtualized by the internal storage apparatus and provided to the host apparatus; wherein when receiving an inquiry command from the host apparatus to a plurality of logical devices which are recognized by the host apparatus as being set to the first channel interface, the first controller recognizes a first device number of a first internal logical device included in the plurality of logical devices from among the plurality of internal logical devices; the first controller sends the inquiry command to the external storage apparatus and recognizes a second device number of a first external logical device included in the plurality of logical devices from among the plurality of external logical devices; the first controller compares a device number of the first internal logical device with a device number of the first external logical device; and if the first device number of the first internal logical device is different from the second device number of the first external logical device, the first controller sets a virtual volume including the second device number to the internal storage apparatus.