Patent ID: 8913338

Claim:
A disk drive comprising: a disk comprising a plurality of servo tracks defined by servo sectors, wherein each servo sector comprises servo data and a servo compensation value; a head actuated over the disk; and control circuitry operable to: define a plurality of data tracks relative to the servo tracks; and while servoing the head over a target data track during a first write operation: generate a position error signal (PES) at each servo sector based at least in part on the servo data; when the servo compensation value of a first servo sector is recoverable, abort the first write operation when the PES generated at the first servo sector exceeds a first write unsafe threshold; when the servo compensation value of the first servo sector is unrecoverable, abort the first write operation when the PES generated at the first servo sector exceeds a second write unsafe threshold less than the first write unsafe threshold; recover the servo compensation value from at least two other servo sectors in the target data track; and generate the second write unsafe threshold based on the servo compensation values recovered from the at least two other servo sectors.