Adaptive off-track recovery

摘要

A method and system for adaptively limiting an off-track recovery displacement of a recording head during an off-track data recovery operation. A head disk assembly (HDA) includes an actuator that positions the recording head in accordance with an actuator control signal. First, an off-track recover displacement threshold is determined utilizing an off-track data field which overlays an on-track data field. The recording head is displaced with respect to the track center until the on-track data field is read. The relative displacement required to retrieve the on-track data is utilized as the threshold. In response to a failed read attempt, a data recovery procedure commences whereby the recording head is incrementally displaced from the track center while attempting to recover the data. During the DRP, the predetermined off-track recovery threshold is utilized to limit the head displacement such that the input/output (I/O) data integrity of the off-track recovery is ensured.