A magnetic disk device includes a disk including a plurality of areas divided in a radial direction, a head, and a controller configured to control the head to write data to a first area including a plurality of tracks that are separated from each other, and a second area including at least two adjacent tracks that partially overlap. A first distance between track centers of said two adjacent tracks in the radial direction is different from a second distance between track centers of another two adjacent tracks in the second area in the radial direction.

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.

A magnetic disk device includes a disk including a plurality of areas divided in a radial direction, a head, and a controller configured to control the head to write data to a first area including a plurality of tracks that are separated from each other, and a second area including at least two adjacent tracks that partially overlap. A first distance between track centers of said two adjacent tracks in the radial direction is different from a second distance between track centers of another two adjacent tracks in the second area in the radial direction.

A magnetic disk device includes a disk has a first area in which data is written by first recording method such that a plurality of tracks are spaced from each other, and a second area written with data by second recording method such that adjacent tracks partially overlap, a head, and a controller. The controller is configured to control the head to write data to a track of the first or second area by the first or second recording method, and perform a retry operation when the data has not been written to the track successfully, and repeat the retry operation until the data is written successfully up to a predetermined number of times. When data is being written to a track of the first area, the retry operation is repeated up to a different number of times depending on a location of the track within the first area.

Two or more different elapsed time values are determined between transitions of a data signal applied to a magnetic write transducer of a heat-assisted magnetic recording apparatus. Two or more different power values of the laser are respectively associated with the two or more different elapsed time values. The two or more different power levels are selected to reduce differences between track widths of recorded marks having the two or more different elapsed time values.

Systems and methods for proactive transfer of stored data between storage zones to avoid anticipated bit rot are provided. In embodiments, a method includes: determining that one or more quality prediction parameters of a storage zone of a data storage device meet a predetermined threshold for user access or adjacency to another storage zone determined to be unhealthy; and initiating a proactive refreshing of the storage zone based on the determining that the storage zone meets the predetermined threshold, the proactive refreshing of the storage zone including: reading all data in the storage zone; determining that no errors have occurred during the reading of the data; and based on the determination that no errors have occurred, moving all of the data of the storage zone to a new storage zone.

According to one embodiment, an electronic communication device includes a controller which controls, according to the number of bit data in which an error has occurred of packet data transferred in serial communication, whether to start logging of information about the error of the packet data or stop logging of information about the error of the packet data.

A system, according to one embodiment, includes: a processor, and logic that is integrated with the processor, executable by the processor, or integrated with and executable by the processor. Moreover, the logic is configured to: detect, by the processor, a change in a resistance value of at least one of a plurality of detector structures, for identifying a defect on a magnetic medium. Each of the detector structures includes a pair of conductive layers separated by an insulating material. However, none of the detector structures include an operable reader for reading data from a magnetic medium. Other systems, methods, and computer program products are described in additional embodiments.

A method includes determining whether a tunneling magnetoresistance (TMR) sensor is corroded using resistance, amplitude and signal to noise ratio (SNR) measurements of the sensor. A method to determine whether a TMR sensor is corroded includes determining an expected initial resistance value, R.sub.TMRoUse and measuring a resistance value, R.sub.TMR, of the sensor. The method includes calculating a ratio of the R.sub.TMR value and the expected initial resistance value, R.sub.TMRoUse and determining whether the ratio is in a predefined range for the TMR sensor. In response to determining that the ratio of the sensor is within the predefined range, the method includes outputting an indication that the TMR sensor is corroded. In response to determining that the ratio of the sensor is outside the predefined range, the method includes outputting an indication that the TMR sensor is not corroded.

A method for testing a multiple-actuator storage device includes accessing a first storage device comprising at least a first and a second logical unit and concurrently performing a first group of test operations on the first logical unit and a second group of test operations on the second logical unit. The method includes monitoring for an interruption during the performing the group of test operations on the first or the second logical unit, and during the monitoring, if it is determined that there is an interruption on one of the first or second logical units, performing the respective test operations on the other logical unit is temporarily suspended. The method also includes continuing to monitor for the interruption, and upon determining that the interruption is not currently active, resuming concurrently performing the test operations on the first and second logical units.