A data storage device is disclosed comprising a head actuated over a disk. A spiral track is written on the disk, and a disk locked clock (DLC) is synchronized to the spiral track. The spiral track is read to generate a spiral track crossing signal, and the spiral track crossing signal is processed to generate a position error signal (PES) representing a position of the head over the disk. When the DLC indicates a first part of the spiral track crossing signal is corrupt, the corruption is compensated in order to generate a compensated PES. While servoing the head over the disk based on the PES, a plurality of concentric servo sectors are written on the disk based on the DLC.

An apparatus, according to one embodiment, includes a module having an array of transducers, and at least two expansion elements positioned proximate the array of transducers. The expansion elements are arranged side by side along a line extending parallel to a longitudinal axis of the array of transducers, wherein the array of transducers includes at least three servo readers. A controller is electrically coupled to the expansion elements, and is configured to individually control an extent of expansion of each expansion element based on feedback from the servo readers.

Some embodiments of the present invention logically eliminate an end region of a user-data area of a magnetic storage tape during formatting (or re-formatting) of the tape, if the position error signal (PES) variance corresponding to the end region exceeds a threshold. An adjacent region, having a PES variance less than the threshold is designated as a new end region, thereby shortening the user-data area of the tape and extending its usable life.