The present disclosure describes aspects of constant-density writing for magnetic storage media. In some aspects, a constant-density writer delays transitions between bits within write data to enable constant-density writing. The write data has an initial bit period based on a constant clock signal, which is generated based on the rotation of a media disk. The constant-density writer modifies the write data to generate phase-delayed write data, which has a bit period that is greater than or equal to the initial bit period. To realize this bit period, the constant-density writer changes write phases of bit transitions within the write data. The constant-density writer can also insert stretch bits, filter single-bit transitions, and mitigate glitches within the phase-delayed write data.

A heat-assisted magnetic recording device includes a granular magnetic recording layer and a thermal absorption layer formed on top of the magnetic recording layer. The thermal absorption layer is patterned to include rows extending in a cross-track direction of the magnetic media, each adjacent pair of the rows being separated from one another by an insulating material.

A data storage device is disclosed comprising a head actuated over a disk. The head is used to read servo information from the disk and generate a position error signal (PES) representing a position of the head over the disk. A control signal is generated based on the PES and a triangle-shape dither signal, and the head is positioned over the disk using the control signal.

According to one embodiment, a magnetic disk device includes a disk, a head which writes data to the disk and reads data from the disk, and a controller which increases a first recording density of data to be written to a first sector having a first overwrite in the first sector and reduces a second recording density of data to be written to a second sector having a second overwrite different from the first overwrite, on a first track of the disk.

A method includes monitoring operations performed on tracks in a main storage area of a disc, and identifying a track of the tracks in the main storage area susceptible to adjacent track interference (ATI). When a track is identified, the identified track or an adjacent track which contributes to ATI of the identified track is remapped to an ATI safe zone of the disc having a tracks per inch (TPI) density lower than a TPI density of the main storage area.

Various implementations of hard disk track management method, device, and system disclosed herein enable improvements of file system write bandwidth. In various implementations, a method is performed at a disk storage including a file controller controlling a disk drive with a disk platter that is divided into multiple regions including a fast region. In various implementations, the method includes receiving a write request associated with data to be written to the disk drive and in response, determining a disk utilization of the disk drive. In various implementations, the method further includes placing the disk drive in a surge mode to write the data to the fast region upon determining that the disk utilization is above a first threshold, and placing the disk drive in a non-surge mode to write the data to other regions of the multiple regions upon determining that the disk utilization is below a second threshold.

The present disclosure describes aspects of constant-density writing for magnetic storage media. In some aspects, a constant-density writer delays transitions between bits within write data to enable constant-density writing. The write data has an initial bit period based on a constant clock signal, which is generated based on the rotation of a media disk. The constant-density writer modifies the write data to generate phase-delayed write data, which has a bit period that is greater than or equal to the initial bit period. To realize this bit period, the constant-density writer changes write phases of bit transitions within the write data. The constant-density writer can also insert stretch bits, filter single-bit transitions, and mitigate glitches within the phase-delayed write data.

Systems and methods for servo zone transition optimization are described. In one embodiment, the storage system device includes a disk drive and a controller. In some embodiments, the controller may be configured to assess at least one operation of a read/write head of the disk drive; and format, based at least in part on the assessing of the read/write head, a disk surface of the disk drive with a first servo zone, a second servo zone, and an overlap region extending between a start point of the second servo zone and an end point of the first servo zone. In some cases, the overlap region starts towards a disk inner diameter (ID) and ends towards a disk outer diameter (OD).

Systems and methods for servo zone transition optimization are described. In one embodiment, the storage system device includes a disk drive and a controller. In some embodiments, the controller may be configured to assess at least one operation of a read/write head of the disk drive; and format, based at least in part on the assessing of the read/write head, a disk surface of the disk drive with a first servo zone, a second servo zone, and an overlap region extending between a start point of the second servo zone and an end point of the first servo zone. In some cases, the overlap region starts towards a disk inner diameter (ID) and ends towards a disk outer diameter (OD).

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.