Abstract: A disk storage system uses a disk on which servo data used for head positioning control is recorded as a storage medium. On the disk, servo burst data constructed by first to eighth burst patterns (A to H) having a recording width which is the same as a track width are recorded in a plurality of servo sectors provided in each track. The first and second burst patterns (A, B) are arranged in the opposite positions in the radial direction with the track center set as a reference (boundary position). The third and fourth burst patterns (C, D) are arranged in the opposite positions in the radial direction with the boundary between the adjacent tracks set as a reference. The fifth and sixth burst patterns (E, F) are arranged in the opposite positions in the radial direction with a preset position X1 in the range of the track set as a reference.