Patent ID: 7237078

Claim:
A computer system comprising: a first and second computer; at least one first storage system connected to the first computer; and a plurality of second storage systems connected to the second computer as well as being connected to the at least one first storage system, wherein the at least one first storage system and the plurality of second storage systems each comprises at least N storage areas for storing data, N being an integer equal to 2 or greater, and there is established N copy pair composed of one storage area in the at least one first storage system and one storage area in the plurality of second storage systems, wherein the first computer comprises: a write request issue module configured to issue a write request to the at least one first storage system, the write request being stamped with an issue time, the write request containing information indicating a storage area in the at least one first storage system, the write request being one of a normal write request and a control-use write request, the normal write request requesting that data be written to the indicated storage area, the control-use write request being issued at predetermined periodic intervals, the first storage system comprises: a write request receiver configured to receive the issued write request; a write request reflector configured to execute a process requested by the received write request; and an update-data transmitter configured to transmit the received write request, as update-data, to the second storage system having a storage area that constitutes a copy pair with the storage area in the at least one first storage system indicated by the received write request, in such a way that the order in which the write requests are issued is ascertainable, the second storage system comprises: an update-data receiver configured to receive the transmitted update-data; and an update-data reflector configured to execute a process requested by the received update-data, responsive to an execute instruction from the second computer, and the second computer comprises: a time acquirer configured to acquire from the plurality of second storage systems the issue time stamped on the update-data received by the plurality of second storage systems; a standard time setting module configured to set a standard time on the basis of the acquired issue time; and an execute instructor configured to instruct the plurality of second storage systems to execute a process requested by the update-data that, of the update-data received by the plurality of second storage systems, is stamped with the issue time that is at or prior to the standard time.