Patent ID: 8988799
Filing Date: 2015-03-24
Classification: G11B

Abstract:
1. A magnetic disk device comprising: a magnetic head; a magnetic disk corresponding to the magnetic head; and a controller configured to write data to the magnetic disk with the magnetic head, wherein the controller detects an amount of offtrack occurring at the time of writing to a write target track, and executes any of a first process to perform a write retry to the write target track, a second process to perform the write retry to the write target track and perform reading for data verification to an adjacent track adjacent to a side on which the offtrack occurs at the time of the writing to the write target track, and a third process to perform the write retry to the write target track and write data of the adjacent track to another track, based on a result of comparison between the detected offtrack amount and a plurality of different slice values, and wherein the controller counts the number of times of writing to the write target track such that an addition value per writing becomes larger in the order of the first process, the second process, and the third process and executes a refresh process to read and rewrite the data of a track in which the counted number of times of writing exceeds a predetermined slice value.