There are provided a method and apparatus for high-speed compensating
repeatable run-out in a hard disk drive. The method includes a) obtaining
a value of a position error signal (PES) of the hard disk drive, the PES
being a relative position signal of the head with respect to the center
of the target track of the disk; b) determining whether the head is in
the settling mode; c) if the head is in the settling mode, compensating
the RRO error without feeding back the PES; and d) if the head is in the
track-following mode, compensate the RRO error by feeding back the PES.
Accordingly, an excessive RRO error is compensated. Even though the hard
disk drive receives an external shock or is assembled in an offline servo
writing manner, the performance of the hard disk drive does not
deteriorate.