Magnetic disk device and method for correcting positon of head

A method for correcting a position of a head applied to a magnetic disk device which comprises a disk comprising a track comprising a plurality of servo sectors, a head comprising write head configured to write data to the disk, and a plurality of read heads which read the data from the disk, the method comprising:

• acquiring a plurality of pieces of correction data for repeatable runout of the disk in parallel by the read heads;
• acquiring a first correction data and a second correction data based on the correction data;
• writing the first correction data and the second correction data to the disk;
• correcting the position of the head based on the first correction data and the second correction data;
• acquiring the correction data at positions other than a first position and a second position in a radial direction of the disk in a first region from the first position to the second position;
• and
• calculating the first correction data corresponding to the first position and the second correction data corresponding to the second position based on the correction data.

A magnetic disk device, comprising:

• a disk comprising a track comprising a plurality of servo sectors;
• a head comprising a write head which writes data to the disk and a plurality of read heads which read the data from the disk;
• and
• a controller configured to acquire a plurality of pieces of correction data for repeatable runout of the disk in parallel by the read heads, acquire a first correction data and a second correction data based on the correction data, write the first correction data and the second correction data to the disk, and correct a position of the head based on the first correction data and the second correction data, wherein
• the controller is configured to acquire the first correction data at a first position by a first read head among the read heads in a first region from the first position to a second position in a radial direction of the disk and acquire the second correction data at the second position by a second read head among the read heads, and to correct the second correction data acquired by the second read head, which is not used for positioning of the head, to a third correction data and correct the position of the head based on the first correction data and the third correction data.