Patent ID: 7769968

Claim:
A storage system being adapted to be coupled to a first host system, the storage system comprising: a first storage controller connected to the first host system; a second storage controller; and a third storage controller; wherein said first controller, said second controller and said third controller are interconnected with each other; and wherein: the first storage controller comprises a first command device and a first volume, the first command device being a destination of a control command issued by the first host system, and the first volume being a destination of write data sent from the first host system and corresponding to a physical storage area managed by the first storage controller; the second storage controller comprises a second command device and a second volume as a virtual volume, the second command device being a destination of the control command received via the first command device of the first storage controller, and the second volume being a remote-copy pair with the first volume and a destination of copy data of the write data stored in the first volume; and the third storage controller comprises a third command device and a third volume, the third command device being a destination of the control command sent via the second command device as well as the first command device, and the third volume being a remote-copy pair with the second volume and a destination of the copy data stored in the second volume and corresponding to a physical storage area managed by the third storage controller, wherein: in a case where a failure of connection between the first storage controller and the second storage controller occurs, the third storage controller: issues, in response to a control command regarding suspension received by the third command device via the first command device, a control command to the second command device, and changes a status of the third volume to “primary”, and perform remote-copy pair between the third volume and the second volume in order to resume operation of the storage system.