FIELD: information technologies.
SUBSTANCE: medium comprises an area of user data for storage of the second data unit. The second unit comprises updated data for data updating in the first data unit recorded in the area of user data using a method of logical overwriting. In the reserve area a substitution unit is stored, which substitutes the second data unit. A defect management area comprises a defect element, containing information on location of the first data unit, and information on location of a substitution unit. The second data unit comprises information on location of the first data unit. The substitution unit comprises information on location of the second data unit.
EFFECT: improved efficiency of data reproduction.
2 cl, 16 dwg
