Patent ID: 6954876

Claim:
A disk apparatus for reading and writing data to a storage medium, wherein: said disk apparatus comprises: a storage means for storing pieces of defective track information into areas at respective addresses each corresponding to physical track number information, with each piece of the defective track information indicating existence of defective tracks in a plurality of tracks, and for storing pieces of defect information in predetermined groups, with each piece of the defect information indicating information on a defective track in said plurality of tracks; and a processing means for receiving an instruction of read or write to a track of said storage medium, for referring to said storage means, and for performing defect processing on a defective track, wherein said storage means stores pieces of pointer information for groups of said pieces of defective track information, with each piece of the pointer information indicating a start address of a storage area for each of said predetermined groups, and when said processing means receives an instruction of read or write to a track of said storage medium, said processing means refers to a piece of said defective track information based on said respective addresses, and then, when existence of a defective track is indicated, refers to a piece of pointer information for group to which said piece of the defective track information belongs, accesses the pieces of defect information on defective tracks sequentially from a storage area indicated by said piece of pointer information, detects defect information when the track as an object of said instruction is a defective track, and performs defect processing on said defective track based on said defect information.