Patent ID: 7035973

Claim:
A storage control apparatus comprising: a first port connected to a first information processing apparatus; a second port connected to a second information processing apparatus; a plurality of logical volumes that store write data received from a plurality of information processing apparatuses via the first port and the second port; a processor that controls writing and reading of data to and from the logical volumes; and a memory that is referred to by the processor, wherein the memory stores mounting information that indicates as to whether each of the plurality of logical volumes is in a mounted state with any one of the information processing apparatuses, wherein prior to one of said first and second information processing apparatuses conducting writing or reading of data to or from a logical volume via said processor, a mounting operation is conducted to mount said logical volume with respect to said one of said first and second information processing apparatuses, thereby setting said mounting information to indicate that such logical volume is in said mounted state, wherein when a logical volume is in the mounted state, the logical volume is made to be accessible by said one of said first and second information processing apparatuses and not the other of said first and second information processing apparatuses, and wherein when a logical volume is in an un-mounted state, said logical volume can be made to be accessible by any one of said first and second information processing apparatuses.