A data storage device is disclosed comprising a voice coil motor (VCM) having a resonance frequency, a first disk surface comprising a first set of servo sectors written at a frequency less than twice the VCM resonance frequency, and a second disk surface comprising a second set of servo sectors circumferentially offset from the first set of servo sectors and written at a frequency less than twice the VCM resonance frequency. An access of the first disk surface is performed by reading at least one of the first set of servo sectors to generate a first position error signal (PES), reading at least one of the second set of servo sectors to generate a second PES, and controlling the VCM based on the first PES and the second PES to position a first head over the first disk surface while accessing the first disk surface.

According to one embodiment, a magnetic disk device includes a magnetic disk including at least one servo zone that includes a first data storage track with a first servo pattern having a first frequency and a second data storage track with a second servo pattern having a second frequency, wherein the first data storage track is located closer to an outer diameter of the magnetic disk than the first data storage track and the first frequency is greater than the second frequency; a magnetic head that faces the magnetic disk; and a zone servo switching unit that switches a servo pattern frequency employed to position the magnetic head in a radial direction based on a radial position of the magnetic head.

A recording surface of a magnetic disk is divided into first and second zones. A first head of a first actuator arm assembly reads from and/or writes to the first zone exclusively. A second head of a second actuator arm assembly reads from and/or writes to the second zone exclusively. The first and second head are capable of simultaneously reading from and writing to the recording surface.

A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of data tracks, including consecutive data tracks N1 and N. A first write to data track N is performed using a first position error signal (PES) representing a position of the head relative to the data tracks. A track squeeze metric is generated for data track N1 based on at least the first PES of the first write. The track squeeze metric for data track N1 is accumulated during the first write, and the first write is aborted when the accumulated track squeeze metric for data track N1 exceeds a first threshold.

A tape drive-implemented method, according to one embodiment, includes: detecting a read error, and sending one or more instructions to perform a first re-read attempt on a portion of a magnetic tape corresponding to the read error. In response to determining that the first re-read attempt was unsuccessful, a range of tension settings is selected. A range of lateral offsets is also selected. Moreover, one or more instructions are sent to apply each unique combination of a tension setting from the range of tension settings and a lateral offset from the range of lateral offsets. For each of the unique combinations applied, one or more instructions are sent to perform a second phase re-read attempt on the portion of the magnetic tape corresponding to the read error. Furthermore, a determination is made as to whether the second phase re-read attempt was performed successfully for any of the unique combinations.

According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.

According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.

A recording surface of a magnetic disk is divided into first and second zones. A first head of a first actuator arm assembly reads from and/or writes to the first zone exclusively. A second head of a second actuator arm assembly reads from and/or writes to the second zone exclusively. The first and second head are capable of simultaneously reading from and writing to the recording surface.

First tracks are read via a first head that is moved via a first actuator over a first, radially-defined, zone of a disk surface. Second tracks are read via a second head that is moved via a second actuator over a second zone of the disk surface that is separate from the first zone. The first and second heads are optimized to read data within first and second skew angle ranges associated with the first and second zones. The first and second skew angle ranges are each less than a total skew angle range of the disk surface.

A sequence of symbols is generated to describe a set of write data, the symbols having a length of nT, where T is a channel clock rate and n is an integer over a predetermined range. Bi-directional write currents are applied to a write pole to record the sequence of symbols to a magnetic storage medium. The write pole has an effective footprint with a downtrack length of mT, where m is an integer. The write currents are switched between a first rail current and a second rail current for alternating symbols, the write currents further transitioning to an intermediate current value for at least one channel clock period for symbols longer than 1T. Write currents are applied to the write pole when recording symbols having a length longer than mT using the effective footprint of the write pole as an interval.