Zone self-servo write (SSW) technology is disclosed that leverages two clock signals synchronized in parallel to transition between zones to write servo patterns at different frequencies while minimizing error rate despite the different frequencies. Two separate clock signals (clocks) are used to locate and lock to different reference spirals. By updating both clocks in parallel instead of in series, error rate for writing while stepping up frequency across zones is reduced.

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).

A method of determining radial position of a magnetic head that includes a first read sensor and a second read sensor includes: with the first read sensor, detecting a servo spiral formed on a disk; with the second read sensor, detecting the servo spiral; measuring a time interval between when the servo spiral is detected by the first read sensor and when the servo spiral is detected by the second read sensor; and based on the time interval, determining a radial position of the magnetic head relative to the disk.

A magnetic disk device detects a shift of writing positions of a spiral pattern, corrects the regulation speed in a direction where the shift is canceled, and writes spiral patterns based on the corrected regulation speed.

According to one embodiment, a magnetic disk device comprises a disk, a first head, a second head, a controller. The disk includes a first surface and a second surface different from the first surface. The first head carries out read and write of data from and to the first surface. The second head carries out read and write of data from and to the second surface. The controller adjusts a spiral speed of at least one of the first head and the second head according to a cylinder offset amount corresponding to a positional difference between the first head and the second head. The spiral speed is a speed at which spiral servo patterns are to be written.

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).

This disclosure describes apparatuses and techniques for multi-channel servo demodulation. Multiple servo demodulation channels enable additional information to be obtained during the self-servo writing process, such as relative positions of multiple read heads and tracking of multiple servo patterns. This additional information enhances accuracy for self-servo writing and can lead to higher recording densities in media drives, and thus more storage with little or no additional cost.

High thermal gradient heatsinks for heat assisted magnetic recording media are provided. One example magnetic recording medium for heat assisted magnetic recording includes a substrate, a first seed layer on the substrate, a heatsink layer on the first seed layer and including Ru having a crystal texture of (11.0), a second seed layer on the heatsink layer, and a magnetic recording layer on the second seed layer. Methods for manufacturing such magnetic recording media are also disclosed.

A data storage device is disclosed comprising a first head actuated over a first disk surface comprising a first spiral track written from an outer diameter (OD) of the first disk surface to an inner diameter (ID) of the first disk surface, and a second head actuated over a second disk surface comprising a second spiral track written from an ID of the second disk surface to an OD of the second disk surface. A seek operation of the first head over the first disk surface is performed in order to access the first disk surface by reading the second spiral track from the second disk surface, seeking the second head over the second disk surface based on reading the second spiral track, and after seeking the second head over the second disk surface, accessing the first disk surface using the first head.