Patent ID: 7809978

Claim:
A control device that controls a storage device to scan data stored in a storage medium of the storage device to locate and correct error in the data, the control device comprising: a first scanning unit that causes the storage device to scan data stored in the storage medium while the storage device is in an idle state; a determining unit that determines whether a proportion of scanned data in entire data in the storage medium is equal to or more than a threshold value; a second scanning unit that, when the determining unit determines that the proportion of the scanned data is less than the threshold value, causes the storage device to scan unscanned data in the storage medium during a time interval between commands received by the storage device from outside while the storage device is not in an idle state, until the proportion of the scanned data is equal to or more than the threshold value; and a threshold value managing unit that manages the threshold value, and increases the threshold value at a predetermined rate over time.