A hard-disk drive. The hard-disk drive includes a magnetic-recording disk in which tracks adjacent to each other are magnetically separated, a spindle motor which drives the magnetic-recording disk, a magnetic-recording head equipped with write element and read element, an actuator for positioning the magnetic-recording head on a predetermined track on the magnetic-recording disk, and a control unit. The control unit is configured to store information about an over-write-only track that is provided for a plurality of tracks including n consecutive tracks in at least a partial radial area of the magnetic-recording disk and an offset amount. In a radial area of the magnetic disk where the over-write-only track is located, the control unit is configured to record with an offset by an offset amount from a center of a track toward the over-write-only track with respect to n−1 tracks of the plurality of n tracks, excluding the over-write-only track.