In a hard disk drive where data is read from and written to a magnetic disk by
a magnetic head in accordance with a command from a host computer, a moving distance
of the magnetic head in a radial direction is detected within a predetermined period
of time. The magnetic head is moved for seeking by a predetermined distance when
the moving distance detected is small. The system and method of the present invention
reduces write failures due to the undulation of a lubricant film on the magnetic
disk by effectively preventing undulation.