Patent ID: 7231466

Claim:
A method of controlling data transfer in a switch system coupled to an initiator and a plurality of storage devices, the initiator using logical unit identification information of a logical unit to access the switch system, and each of the storage devices having a plurality of disk drives, the method comprising: a first status comprising: receiving data of a first data input request, the first data input request being sent from the initiator and being targeted to the logical unit identification information, and transferring the data of the first data input request to a first storage device of the storage devices so that the first storage device inputs the data of the first data input request into a storage area of the disk drives of the first storage device; a second status comprising: transferring data stored in the first storage device to a second storage device of the storage devices, a third status comprising: receiving data of a second data input request, the second data input request being sent from the initiator and being targeted to the logical unit identification information, and transferring the data of the second data input request to the second storage device so that the second storage device inputs the data of the second data input request into a storage area of the disk drives of the second storage device, wherein the second status is conducted between the first status and the third status, and wherein the switch system controls to allow or deny authorizing a reserve to the initiator based on whether or not another initiator is allowed authorizing the reserve authority of the logical unit of the logical unit identification information.