Patent ID: 8892832
Filing Date: 2014-11-18
Classification: G06F

Abstract:
1. A storage apparatus comprising: a cache memory; a storage device that stores data; a data copy unit that copies data stored in the storage device onto a duplicate storage device; a management information storage unit that stores differential information, the differential information indicating whether there is a difference between the data stored in the storage device and data stored in the duplicate storage device; a controller that writes data into the storage device according to a request for writing the data into the storage device; and a difference management unit that, when data is written into the storage device, stores the differential information in the management information storage unit; wherein: when a separation copy, which does not allow data rewriting during copying, is requested, the data copy unit executes the separation copy if the differential information stored in the management information storage unit indicates a difference between the data stored in the storage device and the data stored in the duplicate storage device, when writing data into the storage device, the controller stores the data to be written into the storage device in the cache memory if the data copy unit is executing a separation copy, and if the data copy unit is executing a separation copy, after completing the separation copy, the controller writes the data stored in the cache memory in the storage device.