Patent ID: 7080202

Claim:
A storage system comprising: a first storage device coupled to an information processing device and having a first controller and a plurality of first disk drives, said first disk drives can be related to a first logical volume and a second logical volume; said first controller storing data received from said information processing device in said first disk drives and receiving a first command sent from said information processing device and transferring at least a first part of said first command to a second storage device, said first command or said first part of said first command being used to request a change of a first pair status of said first logical volume and said second logical volume in said first storage device, said second storage device or a (N−1)th (N =positive integer of no fewer than 3) storage device and a change of a second pair status of a third logical volume and a fourth logical volume in a Nth storage device; said second storage device coupled to said first storage device and having a second controller and a plurality of second disk drives, said second disk drives can be related said first logical volume and said second logical volume; said second controller storing data in said second disk drives and receiving said first part of said first command from said first storage device and transferring at least a second part of said first command which is contained in said first part of said first command to said Nth storage device, said second part of said first command being used to request said change of said second pair status; said Nth storage device coupled to said second storage device or said (N−1)th storage device and having a Nth controller and a plurality of Nth disk drives; and said Nth controller storing data in said Nth disk drives and receiving said second part of said first command from said second storage device or said (N−1)th storage device and changing said second pair status in response to said second part of said first command; wherein said first controller, said second controller or a (N−1)th storage controller changes said first pair status in response to said first command or said first part of said first command.