According to one embodiment, a magnetic disk device includes a disk, a head including a main magnetic pole having a first end and a second end opposite to the first end in a radial direction of the disk, a write shield facing the main magnetic pole with a gap, and an assist element provided in the gap and at a position where a first distance between the first end and the assist element and a second distance between the second end and the assist element are different from each other, and a controller which controls a voltage applied to the assist element according to a shingled write direction in which a second track is overwritten on a first track.

According to one embodiment, a magnetic disk device includes a first actuator which actuates a magnetic head portion including a magnetic head, a second actuator which adjusts a position of the magnetic head on a magnetic disk in a radial direction of the magnetic disk, and a control portion which determines a second measurement signal amplitude when a second transfer function is measured in accordance with a first gain estimated value of the second actuator and an amplitude of a first measurement signal amplitude to the second actuator applied when a first transfer function is measured, which calculates a second gain estimated value of the second actuator based on the first transfer function and the second transfer function, and which updates the first gain estimated value, using the calculated second gain estimated value.

According to one embodiment, a manufacturing method of a magnetic disk device including a magnetic disk that stores information, and two or more control devices is provided. The method includes acquiring power consumption of each of a plurality of control devices to be able to be included in the magnetic disk device; and selecting a combination of two or more control devices to reduce variation in total power consumption, on the basis of the acquired power consumption.

Various illustrative aspects are directed to a data storage device, comprising one or more disks; at least one actuator mechanism configured to position at least a first head proximate to a first disk surface and a second head proximate to a second disk surface; and one or more processing devices. The one or more processing devices are configured to: assign logical tracks to physical tracks of the disk surfaces such that a respective logical track comprises: at least a portion of sectors of a primary physical track, the primary physical track being on the first disk surface; and at least a portion of sectors of a donor physical track, the donor physical track being on the second disk surface. The one or more processing devices are configured to perform, using the first head and the second head, a data access operation with at least one of the logical tracks.

Various illustrative aspects are directed to a data storage device, comprising one or more disks; at least one actuator mechanism configured to position at least a first head proximate to a first disk surface and a second head proximate to a second disk surface; and one or more processing devices. The one or more processing devices are configured to: assign logical tracks to physical tracks of the disk surfaces such that a respective logical track comprises: at least a portion of sectors of a primary physical track, the primary physical track being on the first disk surface; and at least a portion of sectors of a donor physical track, the donor physical track being on the second disk surface. The one or more processing devices are configured to perform, using the first head and the second head, a data access operation with at least one of the logical tracks.

According to one embodiment, a magnetic disk device includes a first actuator which actuates a magnetic head portion including a magnetic head, a second actuator which adjusts a position of the magnetic heal on a magnetic disk in a radial direction of the magnetic disk, and a control portion which determines a second measurement signal amplitude when a second transfer function is measured in accordance with a first gain estimated value of the second actuator and an amplitude of a first measurement signal amplitude to the second actuator applied when a first transfer function is measured, which calculates a second gain estimated value of the second actuator based on the first transfer function and the second transfer function, and which updates the first gain estimated value, using the calculated second gain estimated value.

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.

A data storage device including an interface, a first actuator, a second actuator, an auxiliary controller, and a primary controller. The auxiliary controller is configured to control positioning of the second actuator. The primary controller is configured to control positioning of the first actuator. The primary controller is communicatively coupled between the interface and the auxiliary controller.

A data storage device is disclosed comprising a first disk comprising a first disk surface, a second disk comprising a second disk surface, an actuator arm, a head coupled to a distal end of the actuator arm, and a ramp for loading/unloading the head. A first elevator actuator is configured to actuate the actuator arm along an axial dimension relative to the first and second disks, and a second elevator actuator is configured to actuate at least part of the ramp along the axial dimension, wherein a simultaneous movement of the first and second elevator actuators is synchronized.

A data storage device is disclosed comprising a first disk comprising a first disk surface, a second disk comprising a second disk surface, an actuator arm, a head coupled to a distal end of the actuator arm, and a ramp for loading/unloading the head. A first elevator actuator is configured to actuate the actuator arm along an axial dimension relative to the first and second disks, and a second elevator actuator is configured to actuate at least part of the ramp along the axial dimension, wherein a simultaneous movement of the first and second elevator actuators is synchronized.