Patent ID: 7363439

Claim:
A control device which can be connected to a host computer that outputs access destination data indicating an access destination; and an external storage control device which has one or more external storage devices; and which transmits external data constituting data that relates to the external storage devices, comprising: a memory part which stores external device information that indicates which external storage device is associated with which access destination data; and a control part which provides a storage device to said host computer based on a virtual device including at least an external storage device, receives access destination data indicating said storage device from said host computer, specifies the external storage device that corresponds to said received access destination data by referring to said external device information, and accesses said specified external storage device; wherein said memory part stores data format information relating to the format of said external data; said external device information includes external storage device identification information that is used to identify said external storage device, and external storage device setting information including information that is set for a predetermined external storage device of said external storage control device; said data format information includes external storage device identification position information indicating where said external storage device identification information is located in said external data, and external storage device setting position information indicating where the external storage device setting information is located in said external data; said control part performs operations (A) and (B) of, (A) when receiving updated external storage device identification position information, re-acquires said external storage device identification information from said external data using, said updated external storage device identification position information, and resets said re-acquired external storage device identification information in said external device information, (B) when receiving updated external storage device setting position information, re-acquires said external storage device setting information from said external data using said updated external storage device setting position information, and resets said re-acquired external storage device setting information in said external device information.