Patent ID: 7885027

Claim:
A magnetic disk drive including a magnetic disk in which a first servo sector and a second servo sector which arrives at a magnetic head subsequently to the first servo sector are written at a specified interval on a data track, and a first data sector and a second data sector, each of which includes an error correction code, being written between the first servo sector and the second servo sector, said magnetic disk drive comprising: a writing module for writing the first data sector before writing the second data sector so that a leading end area of the second data sector overwrites a trailing end area of the first data sector; and a recovery module for executing error recovery procedures for recovering a read error which has occurred in the first data sector that has been overwritten said recovery module recovers, by erasure correction, the read error which has occurred in the first data sector that has been overwritten and wherein at the time of the erasure correction, said recovery module sets the maximum number of overwritten bytes as an erasure pointer from the trailing end of the first data sector.