Abstract: A disk drive is disclosed comprising a plurality of disk surfaces, and a head actuated over each disk surface. An off-track read capability (OTRC) is measured for each disk surface, and a radial density of data tracks for each disk surface is selected in response to the OTRCs. A linear density of at least two disk surfaces is adjusted to balance the OTRCs across the disk surfaces.

Abstract: A disk drive is disclosed comprising a disk, a head for writing data to the disk, and control circuitry coupled to the head. The control circuitry is operable to write data to the plurality of data tracks, read a first data area of a first data track to generate a first read back signal, determine a first quality metric and a channel flag in response to the first read back signal, determine that the first quality metric exceeds a first threshold, apply additional stress to the first data area, reread the first data area to generate a second read back signal, determine a second quality metric in response to the second read back signal, and determine whether the second quality metric exceeds a second threshold.