Patent ID: 9129658
Filing Date: 2015-09-08
Classification: G11B

Abstract:
1. A magnetic disk drive comprising: a disk comprising a plurality of tracks including a first track; a head configured to write data to the disk and to read data from the disk; and a controller configured to control a data write to the disk by the head, and a data read from the disk by the head, wherein the controller is further configured to: manage influence, on the plurality of tracks, of data writes to tracks within outer adjacent track ranges and to tracks within inner adjacent track ranges, using, respectively, first counters and second counters associated with the plurality of tracks, wherein the outer adjacent track ranges are adjacent to the plurality of tracks outside the plurality of tracks, respectively, the inner adjacent track ranges are adjacent to the plurality of tracks inside the plurality of tracks, respectively, the first counters are indicative of numbers of data writes to tracks within the outer adjacent track ranges, respectively, and the second counters are indicative of numbers of data writes to tracks within the inner adjacent track ranges, respectively; manage influence, on the plurality of tracks, of data writes to tracks within adjacent track ranges adjacent to the plurality of tracks on both sides of the plurality of tracks, using, respectively, a third counters associated with the plurality of tracks, the third counters being indicative of values corresponding to numbers of data writes to tracks within the adjacent track ranges adjacent to the plurality of tracks, respectively; rewrite data in the first track to the first track when both a value of a first counter associated with the first track and a value of a second counter associated with the first track are not less than a first value, and a sum of the values of the first counter and the second counter associated with the first track exceeds a first rewrite threshold, the first counter and the second counter associated with the first track being included in the first counters and the second counters, respectively; and rewrite data in a track associated with a third counter to the track associated with the third counter when a value of the third counter exceeds a second rewrite threshold greater than the first rewrite threshold, the third counter being included in the third counters.