Abstract: In order to implement efficient read/write testing by firstly determining read/write test area-sampling positions based on position information relating to any defects detected during optical inspection, and then conducting read/write tests only upon areas neighboring the defects detected during the optical inspection, a magnetic disk to be inspected is retained on a spindle and moved under this state between an optical type of inspection apparatus and a read/write test apparatus, in which apparatus configuration the read/write test apparatus uses position information on any defects detected by the optical type of inspection apparatus and conducts read/write tests only upon neighboring areas of the defects detected by the optical type of inspection apparatus.

Abstract: A method for writing servo sector sets that include a plurality of separate servo sectors on a disk so that servo sectors are present at same circumferential positions but different radial positions. The method includes reading a first servo sector set in a track with a read element such that the track includes first, second and third servo sector sets. The method also includes writing the third servo sector set with a write element at a different radial position from the read element with positional control and timing control using the first servo sector set while skipping the second servo sector set if all servo sectors of the first servo sector set are non-defective. Moreover, the method includes using positional control and timing control using the second servo sector set in the writing of the third servo sector set if the first servo sector set includes a defective servo sector.

Abstract: In an information recording medium for recording and reproducing data thereon on a sector-by-sector basis, the recorded data being managed as at least one file by using a file structure, the file structure includes unused space management information for identifying a used region and an unused region. At least one defective region is registered as an unused region in the unused space management information, the at least one defective region being a region on the information recording medium which is incapable of proper reproduction of the recorded data.