Patent ID: 7633695

Claim:
A disk device, which executes a write process for writing to a storage medium information transmitted from an upper device by request from the upper device, comprising: a medium monitoring unit for monitoring the number of times of the write process to the storage medium to which the information is written by the write process; a medium scan determining unit for determining whether or not to require medium scan for an area which contains a plurality of partitions into which the storage medium is segmented, according to the state of the storage medium; and a medium scan unit for making the medium scan for the area that said medium scan determining unit determines to require the medium scan, wherein said medium monitoring unit counts the number of times of the write process from the upper device to the storage medium for each of a predetermined number of partitions into which the storage medium is segmented; and further wherein said medium scan determining unit determines a partition, the write process number of times to which is larger than a predetermined number of times, to be a target of the medium scan.