Patent ID: 8312185

Claim:
A storage apparatus coupled to a host apparatus, the storage apparatus comprising: a channel package; a plurality of microprocessor packages; a disk package that controls a plurality of disk devices on which a logical volume is implemented; an internal network coupled to the channel package, the plurality of microprocessor packages, and the disk package; and a shared memory accessible by the microprocessor packages, and wherein the channel package stores first control information that indicates which of the plurality of microprocessor packages has an access right to the logical volume; wherein the shared memory receives second control information that indicates which of the plurality of microprocessor packages has an access right to the logical volume, wherein each of the microprocessor packages accesses the shared memory to acquire the second control information and stores the acquired second control information thereon; wherein the channel package, upon receiving an I/O request to the logical volume from the host apparatus, specifies, based on the first control information stored in the channel package, a first microprocessor package of the microprocessor packages that has an access right to the logical volume, and transmits the I/O request to the first microprocessor package, wherein the first microprocessor package, upon receiving the I/O request from the channel package, determines, based on the second control information stored in the first microprocessor package, whether the first microprocessor package has an access right to the logical volume, wherein, if the first microprocessor package determines that the first microprocessor package has an access right to the logical volume, the first microprocessor package transmits a disk I/O command to the disk package, and wherein if the first microprocessor package determines that the first microprocessor package does not have an access right to the logical volume, the first microprocessor package transmits, based on the second control information stored in the first microprocessor package, an indication of which of the microprocessor packages have an access right to the logical volume to the channel package for updating the first control information.