According to one embodiment, a magnetic disk device includes a disk, a head including a write head that writes data to the disk, and a first read head and a second read head that read data from the disk, and a controller that, in reading a first track of a first region of the disk, positions a middle portion of the first read head and the second read head at a first track center of the first track, and in reading a second track of a second region of the disk different from the first region, positions any one of the first read head and the second read head at a second track center of the second track.

According to one embodiment, a storage device includes a storage medium, and a controller which controls reading and writing of data from and to the storage medium. The controller detects write-off-track having a write-off-track amount larger than a threshold value when the data is written, and interrupts writing of the data when the write-off-track is detected. The controller acquires a degradation amount of a write speed or a degree value indicating a degree of the write-off-track, when the write-off-track amount is equal to or smaller than the threshold value. The controller changes the threshold value based on the degradation amount or the degree value.

According to one embodiment, a magnetic recording apparatus measures and stores recording signal quality of a disk at an initial stage, inspects the recording signal quality before data is recorded, determines whether or not the recording signal quality obtained in the inspection satisfies a standard when compared to the stored recording signal quality at the initial stage, adjusts, based on a result of the determination, light irradiation power of a light irradiation element so as to satisfy the standard, determines a read offset amount based on a result of the adjustment, and performs control so that a position of a read head is shifted based on the determined read offset amount.

A data storage device is disclosed comprising a head actuated over a disk comprising servo data for defining a plurality of data tracks, wherein each data track comprises a plurality of data segments. First data is written to data segments of a first data track, and second data is written to data segments of a second data track. After writing the second data, the first data is read at multiple off-track offsets of the first data track to measure an average off-track read capability (OTRC) of the first data track. A cross-track profile is generated for a first data segment of the first data track, and at least part of the cross-track profile is correlated with the measured average OTRC.

According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, and a controller that overwrites a second track on a first track in a first track group, and records a maximum first positioning error in a first direction from the first track to the second track in the first track in a nonvolatile first recording area.

The presently disclosed technology teaches integrating disc drive electronics into a transducer head. Decreased electrical transit times and data processing times can be achieved by placing the electronics on or within the transducer head because electrical connections may be made physically shorter than in conventional systems. The electronics may include one or more of a control system circuit, a write driver, and/or a data buffer. The control system circuit generates a modified clock signal that has a fixed relation to phase and frequency of a bit-detected reference signal that corresponds to positions of patterned bits on the disc. The write driver writes outgoing data bits received from an external connection to off-head electronics directly to the writer synchronized with the modified clock signal. The data buffer stores and converts digital data bits sent from the off-head electronics to an analog signal that is synchronized with the modified clock signal.

According to one embodiment, a magnetic recording apparatus measures and stores recording signal quality of a disk at an initial stage, inspects the recording signal quality before data is recorded, determines whether or not the recording signal quality obtained in the inspection satisfies a standard when compared to the stored recording signal quality at the initial stage, adjusts, based on a result of the determination, light irradiation power of a light irradiation element so as to satisfy the standard, determines a read offset amount based on a result of the adjustment, and performs control so that a position of a read head is shifted based on the determined read offset amount.

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.

According to one embodiment, a magnetic recording apparatus measures and stores recording signal quality of a disk at an initial stage, inspects the recording signal quality before data is recorded, determines whether or not the recording signal quality obtained in the inspection satisfies a standard when compared to the stored recording signal quality at the initial stage, adjusts, based on a result of the determination, light irradiation power of a light irradiation element so as to satisfy the standard, determines a read offset amount based on a result of the adjustment, and performs control so that a position of a read head is shifted based on the determined read offset amount.

According to one embodiment, a magnetic disk device includes a disk, a head that writes data to the disk and reads data from the disk, and a controller that overwrites a second track on a first track in a first track group, and records a maximum first positioning error in a first direction from the first track to the second track in the first track in a nonvolatile first recording area.