Disk device having a function to confirm that a selected head is proper for a disk surface

A disk device comprising:

• a disk recording medium having information recorded thereon;
• a plurality of heads each of which is opposed to each disk surface of the disk recording medium and reads or writes information;
• and
• a servo mechanism for positioning the heads at arbitrary positions of the rotating disk recording medium based on servo information previously recorded on the disk surface;
• wherein for a servo marker for identifying a servo information region where the servo information is recorded, a pattern of a servo marker in the servo information region included in each disk surface is written differently,
• synchronization component compensating data for compensating a synchronization component for positioning is provided in addition to the servo information and for a address mark for identifying the synchronization component compensating data, a pattern of the address mark of the synchronization component compensating data included in each disk surface is written differently,
• wherein the plurality of heads are classified into groups and head group numbers are given to the respective heads, and
• wherein the head group numbers are recorded by the pattern of the servo marker and a small class of the head in the head group is recorded by the pattern of the address mark of the synchronization component compensating data and both of the head group number and the small class are used to confirm whether or not a selected head is proper for the disk surface.