US 12,176,002 B1
Magnetic disk apparatus and method
Nobuhiro Maeto, Yokohama 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 Dec. 20, 2023, as Appl. No. 18/390,530.
Claims priority of application No. 2023-151554 (JP), filed on Sep. 19, 2023.
Int. Cl. G11B 5/00 (2006.01); G11B 5/02 (2006.01); G11B 5/55 (2006.01); G11B 20/12 (2006.01)
CPC G11B 20/1217 (2013.01) [G11B 2020/1232 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A magnetic disk apparatus comprising:
a magnetic disk on which multiple tracks are provided, the multiple tracks each including multiple servo sectors in which servo information is recorded, the multiple servo sectors being arranged at intervals in a circumferential direction, the multiple tracks each including multiple long-distance sectors, each of the multiple long-distance sectors being a region to which data is written, the region having a length in the circumferential direction covering two or more of the multiple servo sectors;
a magnetic head that executes data writing and data reading to and from each of the multiple long-distance sectors; and
a controller that executes an acquisition operation and a protection operation in a write operation to a first portion of a first track being one of the multiple tracks, the first portion being adjacent to one long-distance sector in a second track adjacent to the first track,
the acquisition operation being executed to acquire one or more evaluation amounts corresponding to a squeeze amount of a track pitch based on a set value of the track pitch on the basis of the track pitch in each of two or more first servo sectors, the two or more first servo sectors being two or more servo sectors included in a range between two ends in the circumferential direction of the first portion,
the protection operation being executed to protect data of the second track in a case where a first total value exceeds a first threshold value, the first total value being a total value of the one or more evaluation amounts.