Patent ID: 8554979

Claim:
A storage system comprising: a plurality of disk drives; first and second disk array controllers, each of the first and second disk array controllers including a cache memory storing data temporarily and being configured to control Redundant Array of Independent Disks (RAID) processes on each of the disk drives; a first switch, external of the first and second disk array controllers, being coupled to the first disk array controller and to the disk drives; a second switch, external of the first and second disk array controllers, being coupled to the second disk array controller and to the disk drives; wherein when the first switch receives information related to one destination disk drive, the first switch performs path switching to make a connection to the one destination disk drive, so that data is transferred between the first disk array controller and the one destination disk drive of the disk drives via the first switch, when the second switch receives information related to another destination disk drive, the second switch performs path switching to make a connection to the another destination disk drive, so that data is transferred between the second disk array controller and the another destination disk drive of the disk drives via the second switch controller, and wherein data transfer between the first disk array controller and the one destination disk drive via the first switch is performed separately from data transfer between the second disk array controller and the another destination disk drive via the second switch.