Patent ID: 8327094

Claim:
A networking storage system comprising: a computer; and a storage system comprising: a plurality of storage control units; a first storage control unit of the plurality of storage control units including a first volume, coupled to the computer, the first volume being provided to the computer; a second storage control unit of the plurality of storage control units including a second volume, coupled to the computer, the second volume being provided to the computer; a third storage control unit of the plurality of storage control units including a third volume, coupled to the first control unit and the second control unit, the third volume storing data which is sent from the first control unit or the second control unit, wherein the third volume of the third storage control unit is a pool area, and wherein if a primary volume of the first storage control unit is an actual volume and a secondary volume of the first storage control unit is a virtual volume and a pair of the primary volume and the secondary volume is transferred to the second storage control unit, then: a storage area network is connected in a case where an entity of the primary volume exists in the third storage control unit; the primary volume is copied and transferred via the storage area network in a case where entity of the primary volume exists in the first storage control unit; an address mapping table of the secondary volume is transferred to the second storage control unit; and the second storage control unit updates data in the pool area and data of the actual volume by referring to the address mapping table.