Patent ID: 7721055

Claim:
A system for controlling the updating of a storage device, wherein if data is written into a primary storage device as a result of the reception of a write request by a file system, the data that is written into the primary storage device is copied into a secondary storage device that is logically connected to the primary storage device, and thus the data is copied into the secondary storage device, then a snapshot of the secondary storage device is accumulated in a storage device used for snapshots by copy-on-write, the system comprising a processor that is operated by reading in at least one computer program, wherein the processor sets a lock that is used to prohibit the updating of data corresponding to update data to be read out among the one or more sets of data accumulated in the primary storage device or the secondary storage device each time that update data is read out; acquires a lock waiting time which is a length of time that is required in order to set the each lock, an upper limit value of this lock waiting time, and a frequency threshold value; investigates the number of times that the lock waiting time exceeds the upper limit value to judge whether or not the number of times that the upper limit value has been exceeded exceeds the frequency threshold value; stops the reception of write requests by the file system if the result of this judgment is affirmative; and stops the copy-on-write by cutting off the logical connection between the primary storage device and the secondary storage device.