Patent ID: 7325112

Claim:
A method for speeding up a snapshot operation in a data processing system, the method comprising: copying first data which has been stored in a source-side storage device including a disk-shaped magnetic storage to a snapshot-side storage device including another disk-shaped magnetic storage in response to a first command from a host device connected to both the source-side storage device and the snapshot-side storage device through a switching device; determining, by the switching device, both second data to be copied to the snapshot-side storage device and third data to be successively copied with the second data to the snapshot-side storage device; further copying the second data to the snapshot-side storage device having a predetermined relationship with the first data and simultaneously storing the third data to a memory unit provided within the switching device in response to a second command issued after the first command; and still further copying the third data in the memory device to the snapshot-side storage device having the predetermined relationship with the second data in response to a third command issued after the second command.