Patent ID: 7983123

Claim:
A method of defect management for managing on a block-by-block basis a defective area in an information-recording medium having a user-data area, a sparing area, and a defect-management information area, the block being of a predetermined size, when a defective block in which the defective area is included is set to be replaced with a sparing block of said sparing area, comprising the steps of: dividing said sparing block into a plurality of subblocks so as to set identifying information, for identifying one of the sparing subblocks in which data are replaced and a non-sparing subblock in which data are not replaced, as defect-management information; and setting block-management information, including information regarding said defective block and said sparing block, and information regarding an area in which non-sparing data not replaced with said sparing block are stored, as defect-management information.