MAGNETIC DISK DRIVE AND MAGNETIC HEAD CONTROL METHOD

The invention provides a magnetic disk drive and a magnetic head control method capable of reducing the rotational latency by considering the seek latency which occurs due to the media bump avoidancecontrol executed together with the DFH control, at the reordering operation. When access to the disk is being executed together with the command processing, in the reordering, the command which shouldbe next processed is determined in the command group standing by inside the HDD, the time obtained by summing the seek time determined in accordance with the seek distance and the rotational latencywhich is determined after the seek completion by the positional relationship between the R/W enable sector position and the sector of the evaluated command is used in the command evaluation of the reordering, if the command accessible in the shortest time is selected it is determined whether the media bumps influencing the DFH control exist in the seek section from the previous command completionto the evaluated command sta