Patent ID: 8665545

Claim:
A magnetic recording disk drive comprising: a rotatable magnetic recording disk comprising a substrate and a magnetic recording layer on the substrate; a head carrier having a recording-layer-facing surface; a write head on the head carrier, the write head adapted for generating a generally circular path of magnetic transitions in the recording layer as the disk rotates; an actuator connected to the head carrier for moving the head carrier generally radially across the disk, the actuator being capable of moving the head in an increment less than the radial width of a path, whereby the write head generates partially overlapping generally circular paths of magnetic transitions, the non-overlapping portions of the circular paths representing data tracks, wherein the data tracks are grouped on the recording layer in annular bands separated by annular gaps; a read head on the carrier for reading written data from the data tracks; a controller for selecting the band where data is to be written in the data tracks by the write head, the controller turning on a write-squeeze-verify (WSV) method for verifying the accuracy of data written in the data tracks in the selected band; memory coupled to the controller; and wherein the controller includes logic for executing write-squeeze-verify (WSV) method acts comprising: (a) writing data in a circular path; (b) writing data in an immediately radially adjacent circular path to thereby form a data track; (c) reading data from the data track; (d) verifying the accuracy of the data written in the data track; and (e) if the data written in the data track contains an error, recording the occurrence of a write error in memory; (f) repeating steps (b) through (e) for all data tracks in the selected band; (g) recording in memory the number of data tracks written and calculating, from the number of write errors recorded and the number of data tracks written, a write error frequency (WEF) for the selected band; and (h) if WEF is below a predetermined threshold, turning off WSV for subsequent writing to the data tracks in said selected band.