A self-servo-write (SSW) method in a storage device includes detecting, with a first read head, SSW spiral signals from a first track on a first storage medium surface, processing the SSW spiral signals from the first track using a first read channel, to generate first control signals for positioning the first read head relative to the first track, detecting, with a second read head, SSW spiral signals from a second track on a second storage medium surface, processing the SSW spiral signals from the second track using a second read channel, to generate second control signals for positioning the second read head relative to the second track, positioning a first write head relative to the first track using the first control signals via a single write channel, and positioning a second write head relative to the second track using the second control signals via the single write channel.

According to one embodiment, a magnetic disk device includes a disk, a head including a write head and a first read head and a second read head, and a controller that disposes the first read head at a first radial position of a first track of the disk in a radial direction to read the first track, changes a main read head which serves as a reference for positioning during a read process from the first read head to the second read head when read retrying the first track, disposes the second read head as the main read head at a second radial position different from the first radial position of the first track in the radial direction to read the first track, and changes an internal setting corresponding to the main read head to read the first track.

In accordance with an embodiment, a hard disk drive includes voice coil motors (VCMs) coupled to respective control units configured to drive retract an operation of the VCMs in the hard disk drive. The retract operation of the VCMs includes a sequence of retract steps. The control units are allotted respective time slots for communication over a communication line with the respective time slots synchronized via the common clock line, and are configured to drive sequences of retract steps of the VCMs in the hard disk drive in a timed relationship.

According to one embodiment, a magnetic disk device includes a disk, a head including a write head and a first read head and a second read head, and a controller that disposes the first read head at a first radial position of a first track of the disk in a radial direction to read the first track, changes a main read head which serves as a reference for positioning during a read process from the first read head to the second read head when read retrying the first track, disposes the second read head as the main read head at a second radial position different from the first radial position of the first track in the radial direction to read the first track, and changes an internal setting corresponding to the main read head to read the first track.

According to embodiments, a magnetic disk apparatus includes a magnetic disk, a magnetic head, a temperature sensor, and a controller. The magnetic disk has formed therein a servo sector in which servo data including a first post code and a second post code is recorded. In the positioning of the magnetic head, the controller performs a correction using a third post code that is based on the first and second post codes and a first temperature detected by the temperature sensor.

According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head including an assist part to assist recording of data into the magnetic disk, a controller configured to control the recording of data by the magnetic head based on a recording condition, and a memory configured to record a first threshold value used to define that an assist element included in the assist part is in a deterioration condition. Furthermore, the controller detects the condition of the assist element, determines whether or not the recording condition is changed based on the detected condition and the first threshold value stored in the memory, and changes the recording condition based on the result of the determination.

Technologies are provided for accessing a physical location of a storage medium reader of a storage device. A computing device can transmit a request for the storage medium reader's physical location. The storage device can determine the physical location of the storage medium reader and transmit the location to the computing device. The computing device can use the physical location of the storage medium reader to determine an expected latency for retrieving one or more stored data items. The computing device can transmit a command to change the physical location of the storage medium reader, for example by changing a location of the storage medium reader with respect to a given storage medium and/or changing a storage medium that is accessed by the storage medium reader. The computing device can control the placement of the storage medium reader in order to optimize retrieval of data items from the storage device.

A self-servo-write (SSW) method in a storage device includes detecting, with a first read head, SSW spiral signals from a first track on a first storage medium surface, processing the SSW spiral signals from the first track using a first read channel, to generate first control signals for positioning the first read head relative to the first track, detecting, with a second read head, SSW spiral signals from a second track on a second storage medium surface, processing the SSW spiral signals from the second track using a second read channel, to generate second control signals for positioning the second read head relative to the second track, positioning a first write head relative to the first track using the first control signals via a single write channel, and positioning a second write head relative to the second track using the second control signals via the single write channel.

A data storage device is disclosed wherein an elevator actuator is controlled to move a head along an axial dimension toward a first disk surface of a first disk while processing a proximity signal generated by a proximity sensor. A first actuator position is detected when the actuator arm is proximate the first disk surface of the first disk based on the proximity signal.

According to one embodiment, a magnetic disk device includes a magnetic disk, a magnetic head including an assist part to assist recording of data into the magnetic disk, a controller configured to control the recording of data by the magnetic head based on a recording condition, and a memory configured to record a first threshold value used to define that an assist element included in the assist part is in a deterioration condition. Furthermore, the controller detects the condition of the assist element, determines whether or not the recording condition is changed based on the detected condition and the first threshold value stored in the memory, and changes the recording condition based on the result of the determination.