Patent ID: 7603517

Claim:
A disk storage device, comprising: a head for either reading or writing data on a track of a storage disk; an actuator for positioning said head on a desired track of said storage disk; a data buffer for storing write data from a host; a command management table for storing command management information which specifies a write position of the write data; and a control unit for storing the write data from said host to said data buffer according to a write command from said host, reporting the status to said host, and then writing said write data in said data buffer on said specified write position in said storage disk by said head, wherein said control unit judges whether two or more pieces of command management information are registered in said command management table, in response to the reception of a command which requires data integrity, other than said write command, stores said write data stored in said data buffer and said command management table onto a save area created on said storage disk when judging that two or more pieces of command management information are registered, reports a response to said host, and then writes said write data stored in the save area on said storage disk in said specified position on said storage disk, and wherein said control unit reports the status to said host, and then writes said write data in said data buffer on said specified write position in said storage disk by said head when judging that only one piece of command management information are registered.