According to one embodiment, disclosed herein is a disk drive that has a disk of discrete-track media (DTM) type. The DTM disk has servo regions. Each servo region has dividing grooves and non-servo data parts. Each dividing grooves extends along the centerline of any projecting region having a width larger than a prescribed value. Each non-servo data part suppresses reproduction noise. The disk drive has a read/write channel that includes a reproduced-signal processing unit. This unit reproduces servo data from each servo region.