US 12,073,855 B2
Magnetic disk device and control method
Daisuke Sudo, Kawasaki Kanagawa (JP)
Assigned to Kabushiki Kaisha Toshiba, Tokyo (JP); and Toshiba Electronic Devices & Storage Corporation, Tokyo (JP)
Filed by Kabushiki Kaisha Toshiba, Tokyo (JP); and Toshiba Electronic Devices & Storage Corporation, Tokyo (JP)
Filed on Feb. 15, 2023, as Appl. No. 18/169,629.
Claims priority of application No. 2022-151633 (JP), filed on Sep. 22, 2022.
Prior Publication US 2024/0105216 A1, Mar. 28, 2024
Int. Cl. G11B 19/28 (2006.01); G11B 5/012 (2006.01); G11B 20/10 (2006.01)
CPC G11B 5/012 (2013.01) [G11B 19/28 (2013.01); G11B 20/10481 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A magnetic disk device comprising:
a magnetic disk, a first area and a second area located on an inner diameter side of the first area being provided therein;
a motor rotating the magnetic disk;
a magnetic head; and
a controller that
receives a write command from a host,
writes, in a case where a first position that is a position designated as a write destination of data by the write command is included in the first area, the data to the first position by the magnetic head while causing the magnetic disk to rotate at a rotational speed of a first value, and
writes, in a case where the first position is included in the second area, the data to the first position by the magnetic head while causing the magnetic disk to rotate at a rotational speed of a second value larger than the first value, wherein
an area, a recording frequency of the magnetic head exceeding a set level in the area, is set as the first area, and
the set level is determined on a basis of an error rate at a time of access.