Patent attributes
Embodiments of the invention relate to erasing data recorded on a magnetic disk with increased certainty by using an external magnetic field. One embodiment is directed to a method for erasing data recorded on a magnetic disk, which is housed in a magnetic disk drive, by using an external erasure magnetic field generated by an external erasure magnetic field generator. The method comprises the steps of: moving a first magnetic disk drive within an external erasure magnetic field in a moving state appropriate for the type of the first magnetic disk drive, and erasing data recorded on a magnetic disk in the first magnetic disk drive; and moving a second magnetic disk drive, which differs in type from the first magnetic disk drive, within an external erasure magnetic field in a moving state that differs from the moving state of the first magnetic disk drive, and erasing data recorded on a magnetic disk in the second magnetic disk drive.