Defect management method for a magnetic recording medium

A method of carrying out defect management on reading data from a disk-shaped magnetic recording medium to be accessed, the magnetic recording medium comprising a plurality of tracks thereon which are arranged with concentric circles, each track being divided in a circumferential direction into a predetermined number of sectors having a length equal to one another, said plurality of tracks being separated into a user data area available to a user, an alternate area, and a management area, said method comprising the steps of:

• retrying reading operation of data up to a maximum retry count when an error is detected on reading of data for a target sector in the user data area;
• overwriting read-out data in the target sector in a case where a retry count is not less than a specific count when retry results in a success;
• and
• registering the target sector in a defect table in the management area and writing read-out data in an alternate sector in the alternate area in a case where an error is detected when overwritten data is reread from the target sector.

A recording medium for recording a program to make a computer execute defect management on reading data from a disk-shaped magnetic recording medium to be accessed, the magnetic recording medium comprising a plurality of tracks thereon which are arranged with concentric circles, each track being divided in a circumferential direction into a predetermined number of sectors having a length equal to one another, said plurality of tracks being separated into a user data area available to a user, an alternate area, and a management area, said recording medium recording the program to make said computer execute:

• processing of retrying reading operation of data up to a maximum retry count when an error is detected on reading of data for a target sector in the user data area;
• processing of overwriting read-out data in the target sector in a case where a retry count is not less than a specific count when retry results in a success;
• and
• processing of registering the target sector in a defect table in the management area and of writing read-out data in an alternate sector in the alternate area in a case where an error is detected when overwritten data is reread from the target sector.