Patent ID: 8156561

Claim:
A first storage device coupled to a computer and a second storage device, comprising: a first port coupled to the computer and being operated as a target port; a second port coupled to the second storage device and being operated as an initiator port; a processor coupled to the first port and the second port; and a volume management information which is set based on port management information by the processor, wherein a first volume controlled by the first storage device is assigned to the first port, wherein a second volume is included in the second storage device so that the second volume is virtualized as the first volume by the first storage device, wherein the port management information is related to an access restriction of the second storage device, wherein the volume management information includes a volume identifier, an initiator port identifier and an external port identifier, and wherein upon receiving a write request to the first volume, if access to the first volume is permitted based on the volume management information, data of the write request is outputted to the second volume.