Patent ID: 7650446

Claim:
A storage system which is a second storage system that is coupled to a first storage system, said first storage system having a first controller, a plurality of first storage devices which form a plurality of first logical volumes, a first switching apparatus interposed between said first controller and said plurality of first storage devices, a first front-end port for receiving an input/output request from a first upper level device, and a first back-end communication port which differs from said first front-end communication port, wherein said first controller receives an input/output request sent from said first upper-level device, and, in accordance with the received input/output request, carries out a data write and/or read to any one of said plurality of first storage devices via said first switching apparatus, said storage system comprising: a second controller; a plurality of second storage devices; a second front-end communication port for receiving an input/output request from a second upper-level device; a second back-end communication port which differs from said second front-end communication port; a second switching apparatus interposed between said second controller and said plurality of second storage devices and connected to said first switching apparatus via said second and first back-end communication ports; wherein said second controller receives an input/output request sent from said first and/or said second upper-level device, and, in accordance with the received input/output request, carries out a data write and/or read to any one of said plurality of second storage devices via said second switching apparatus, wherein said second controller prepares as copying destinations a plurality of second logical volumes corresponding respectively to said plurality of first logical volumes, wherein said second controller carries out copy of data between at least one of said plurality of first storage devices and at least one of said plurality of second storage devices by way of said first switching apparatus, said first back-end communication port, said second back-end communication port and said second switching apparatus, without going through said first controller, and wherein said second controller deletes data stored in said plurality of first logical volumes when the copy of data from said plurality of first logical volumes to said plurality of second logical volumes has ended.