Track defect map for a disk drive data storage system
A method and apparatus for storing a disk drive media defect table or list. Defect table entries for a subject disk track are stored on the subject track and retrieved for determining defective sectors only when the subject track is accessed for a data read or write operation.
1. A method for reading or writing data to a disk of a disk drive data storage system, wherein defect information for an entire track of the disk is stored in the track to which the defect information pertains, the method comprising:
accessing the track where the data is to be read or written;
prior to reading or writing data to the track;
reading the defect information of the entire track;
storing the defect information of the entire track in a memory; and
accessing the defect information of the entire track in the memory to determine a sector of the track for reading or writing the data.
2. The method of claim 1 further comprising after the step of accessing the track defect information, using the track defect information to convert a logical address of the data to a physical address representing the sector of the track for reading or writing the data.
3. The method of claim 1 wherein the defect information of the entire track is stored at a plurality of locations on the track.
4. The method of claim 1 wherein the track defect information occupies less storage space in the memory than defect information for the entire disk.