Patent ID: 7809906

Claim:
A storage control device coupled to a computer and a first storage system, the first storage system including a plurality of storage units, one of which is assigned to a logical unit in the storage control device, the storage control device comprising: a first port coupled to the computer; a second port coupled to the first storage system; and a control unit, coupled to the first port and the second port, which provides the logical unit, converts a first access request for the logical unit received by the first port into a second access request for a first storage unit of the plurality of storage units based on a relationship information including a first relation between the logical unit and the first storage unit, sends the second access request to the first storage system via the second port, and calculates performance of the second access request in the storage control device, wherein the first storage unit of the plurality of storage units is selected by the storage control device based on the relationship information and wherein it is determined whether a conflict over the second port or the control unit exists, whereby the storage control device determines performance of the logical unit in the storage control device.