Patent ID: 7930502

Claim:
A disk array apparatus arranged to be coupled to an external control device including a plurality of external storage devices having a plurality of storage areas, the disk array apparatus comprising: a plurality of storage devices having a plurality of storage areas; and a controller, which is arranged to be coupled to a host computer, controlling a read/write operation of data to or from one of the storage areas of said disk array apparatus and storage areas of said external storage devices in response to a read/write command issued from the host computer, the external storage devices being lower-speed devices than the storage devices of the disk array apparatus, the storage areas of said external storage devices being mapped to the storage areas in the disk array apparatus and provided to the host computer as the storage areas in the disk array apparatus, wherein the controller includes information relating to an access authority to each of the storage areas, the information being used when a read/write command is received for reading/writing data stored in the storage areas of said disk array apparatus or in the storage areas of said external storage devices, and the information being changed in response to an access authority change command to change an access authority received from the host computer, wherein the controller executes control to move the data between one of the storage areas of said disk array apparatus and one of storage areas of the external storage devices, in response to the access authority change command to change an access authority of said one of the storage areas of said disk array apparatus received from the host computer; and wherein the controller executes control to move data from one of the storage areas of the external devices to one of the storage areas of said disk array apparatus, in response to an access authority change command received from the host computer releasing inhibiting of access authority of the host computer to the storage areas of said disk array apparatus to which the data is moved.