A memory system may include: a memory device including a plurality of storage regions; and a controller. The controller may be coupled between a host and the memory device, and perform a read retry operation when a read error occurs in any one of the storage regions based on occurrence possibilities for a plurality of different type of defects in any one storage region where a read error occurred.

In a data storage device having a storage medium, wherein data is written to tracks on the storage medium, data for each track including a preamble, and wherein the preamble in any current track is orthogonal to the preamble in any track adjacent to the current track, and wherein data accumulated in a multi-dimensional space is representative of a relationship between signals from the current track and signals from at least one adjacent track, the relationship between the signals from the current track and the signals from the at least one adjacent track is calibrated by, for each respective position out of a plurality of positions in the multi-dimensional space, accumulating a plurality of data values for the respective position, and determining, from the plurality of data values for the respective position, an inverted covariance matrix without performing a matrix inversion operation, either during run-time or prior to run-time.

According to one embodiment, a magnetic disk device, includes a disk including a track including a plurality of servo sectors, a head including a write head which writes data to the disk and a plurality of read heads which read the data from the disk, and a controller configured to simultaneously acquire a plurality of pieces of correction data for repeatable runout of the disk by the read heads, acquire a first correction data and a second correction data based on the correction data, write the first correction data and the second correction data to the disk, and correct a position of the head based on the first correction data and the second correction data.

Methods and systems for detecting hidden sectors in a hard drive. The method may include initiating a linear copy of the hard drive and, while the hard drive is being copied, capturing images of a platter and an actuator arm within the hard drive using an imaging device. The captured images are output and they indicate a range of movement of the actuator arm across the platter during the linear copy. Ranges of movement that fail to scan across the full expected size of the platter may be indicative of a modified partition record that maliciously hides a portion of the hard drive from the copy operation.

An apparatus may comprise a circuit configured to receive first underlying data corresponding to a first signal and receive a second signal corresponding to second underlying data. The circuit may determine an interference component signal based on the first underlying data corresponding to the first signal and a first channel pulse response shape for the first signal, determine estimated decisions corresponding to the second signal based on the second signal, and determine an estimated signal based on the estimated decisions corresponding to the second signal and a second channel pulse response shape for the second signal. The circuit may then generate a remaining signal based on the estimated signal and the second signal, generate an error signal based on the interference component signal and the remaining signal, and adapt one or more parameters of the first channel pulse response shape based on the error signal.

According to one embodiment, a magnetic disk device includes a disk including a first region and a second region different from the first region, a head that writes data on the disk and reads data from the disk, an actuator that positions the head on the disk, and a controller which positions the head by driving the actuator and writes data in the first region and the second region with the head, a skew angle of the head with respect to a circumferential direction of the disk varying within a first angle in the first region, and varying, in the second region, from a second angle larger than the first angle to a third angle larger than the first angle and the second angle.

According to one embodiment, a magnetic disk device, includes a disk including a track including a plurality of servo sectors, a head including a write head which writes data to the disk and a plurality of read heads which read the data from the disk, and a controller configured to simultaneously acquire a plurality of pieces of correction data for repeatable runout of the disk by the read heads, acquire a first correction data and a second correction data based on the correction data, write the first correction data and the second correction data to the disk, and correct a position of the head based on the first correction data and the second correction data.

A magnetic disk device includes a disk, a head configured to write data on the disk based on a write current, and a controller configured to determine whether a write error occurs when data is written on the disk, based on a change in a heating value of the head, and upon determining that the write error occurs, read the data written on the disk.

A memory system may include: a memory device including a plurality of storage regions; and a controller. The controller may be coupled between a host and the memory device, and perform a read retry operation when a read error occurs in any one of the storage regions based on occurrence possibilities for a plurality of different type of defects in any one storage region where a read error occurred.

A method of forming a recording head for use with a data storage medium in a data storage device. The method includes forming first and second writers of different target geometries. A first recording measurement is performed on one or more storage media using the first writer. A second recording measurement is performed on the one or more storage media using the second writer. Based on a comparison of the first and second recording measurements to a predetermined quantity, either the first writer or the second writer is selected to be operational in the data storage device.