US 11,929,094 B1
Magnetic disk device and method
Syosuke Maruyama, Yamato Kanagawa (JP); and Hideo Shimokawa, Ome Tokyo (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. 28, 2023, as Appl. No. 18/115,396.
Claims priority of application No. 2022-150917 (JP), filed on Sep. 22, 2022.
Int. Cl. G11B 20/18 (2006.01); G11B 5/596 (2006.01)
CPC G11B 20/1879 (2013.01) [G11B 5/596 (2013.01); G11B 20/1816 (2013.01); G11B 2020/183 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A magnetic disk device connectable to a host, the magnetic disk device comprising:
a magnetic disk provided with a first track including a plurality of first sectors (#1-9) and a second sector (#10);
a magnetic head that writes and reads data to and from the magnetic disk;
a memory; and
a controller that,
when a first data segment is stored with a first information piece (300) in each of the plurality of first sectors, the first information piece being attribute information of a first sector storing thereof out of the plurality of first sectors, a first parity is stored in the second sector, and write of a second data segment to a third sector that is one of the plurality of first sectors is requested from the host,
acquires the second data segment from the host and stores the second data segment in the memory,
reads a first data set that includes all first data segments and all first information pieces from the first track and stores the first data set in the memory,
acquires a second information piece that is attribute information of the third sector,
updates, in the memory, a third data segment and a third information piece that are a first data segment and a first information piece read from the third sector out of the first data set with the second data segment and the second information piece,
calculates a second parity on a basis of a second data set that is the first data set after update while writing the second data set to the first track, and
writes the second parity in the second sector.