Patent ID: 8024537

Claim:
A computer system comprising: a first computer; a second computer; a plurality of primary storage systems coupled to the first computer and the second computer, and each including a logical volume for storing data received from the first computer; and a plurality of secondary storage systems coupled to the first computer and the second computer, and each including a logical volume for storing replication data of the logical volume of the primary storage system, wherein the second computer manages copy pairs of a part of the logical volumes of the primary storage systems and a part of the logical volumes of the secondary storage systems, and transmits a group control instruction to the secondary storage systems for controlling a replication process by using the copy pairs as a first copy group, wherein a particular storage system of the secondary storage systems receives a command which adds a second copy group to the first copy group, compares a latest data reflection time of an object of copy with a last write data written time of the logical volumes of the secondary storage systems, changes, if the latest data reflection time does not coincide with the last write data written time, a copy pair status of the second copy group to a copying status, and wherein when the copying status of the second copy group is changed, non-integrity of write data is notified.