Patent ID: 7302535
Filing Date: 2007-11-27
Classification: G06F

Abstract:
1. A storage system A storage system comprising: a plurality of storage control units; and a plurality of disk devices each of which is coupled to one of said plurality of storage control units, wherein each of said plurality of storage control units includes a replication creation unit which creates replication of data of a volume in the disk devices and pair information which is information on a volume of a replication source and a volume of a replication destination, wherein a replication creation unit in one of said plural storage control units copies data on the volume of the replication source to the volume of the replication destination when replication is created in a volume within the disk devices connected to another storage control unit, wherein said one of said plurality of storage control units receives a data update request to the volume of said replication source, stores the received data to a cache memory of said one of said plurality of storage control units and also stores the received data in the cache memory of said another storage control unit, wherein said another storage control unit stores the data stored in the cache memory into the volume of the replication destination, wherein when said volume of the replication source and said volume of the replication destination are used for different uses, the pair information of said volume of the replication source and said volume of the replication destination is set to a split, and when write data is written to one of said volume of the replication source or said volume of the replication destination during the split status, a position of storage area to which said write data is written is maintained in a differential bitmap in a storage control unit controlling said one of said volume of the replication source or said volume of the replication destination.