A data storage device is disclosed comprising a disk comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors, each data sector comprises a preamble, and the preambles of adjacent data tracks are recorded at different frequencies. A first read element and a second read element of a head are positioned over a first preamble of a first data track to generate a first read signal emanating from the first read element and a second read signal emanating from the second read element. A first metric is generated based on the first read signal and a second metric is generated based on the second read signal. A difference between the first metric and the second metric is generated and used, for example, to servo the head over the disk or to measure a radial offset between the read elements.

Techniques for verifying a magnetic tape are disclosed. The techniques include obtaining a position signal generated by reading a magnetic tape using a stationary tape head. Next, a simulated current for adjusting a position of the tape head to follow a track on the magnetic tape is updated using the position signal. The simulated current is then compared to one or more saturation limits to generate a verification result for a servo pattern on the magnetic tape, wherein the verification result classifies the magnetic tape as usable or unusable. Finally, the verification result is outputted for use in managing subsequent use of the magnetic tape.

A computer program product, according to one embodiment, includes a computer readable storage medium having program instructions embodied therewith. The computer readable storage medium is not a transitory signal per se. Moreover, the program instructions readable and/or executable by a controller to cause the controller to perform a method which includes: collecting, by the controller, data relating to operation of a tape drive; storing, by the controller, the collected data in wrap sections of a tape map; and storing, by the controller, a subset of the collected data in a slice region upon experiencing a first trigger condition and/or upon reaching a predefined location on a tape. Moreover, the wrap sections of the tape map correlate to physical lengths of tape. Other systems, methods, and computer program products are described in additional embodiments.

Various implementations described herein are directed to technologies for providing error detection for a disk drive of a digital video recorder (DVR). Access data is measured according to a degree of usage of a disk drive of a DVR. The access data is stored. The stored access data is analyzed to detect performance degradation of the disk drive.

A system according to one embodiment includes a magnetic head having a plurality of sensors arranged to simultaneously read at least three immediately adjacent data tracks on a magnetic medium, wherein none of the sensors share more than one lead with any other of the sensors. Such embodiment may be implemented in a magnetic data storage system such as a disk drive system, which may include a magnetic head, a drive mechanism for passing a magnetic medium (e.g., hard disk) over the magnetic head, and a controller electrically coupled to the magnetic head.

Various implementations described herein are directed to technologies for providing error detection for a disk drive of a digital video recorder (DVR). Access data is measured according to a degree of usage of a disk drive of a DVR. The access data is stored. The stored access data is analyzed to detect performance degradation of the disk drive.

In general, techniques are described for monitoring health of a head in a magnetic data storage drive. A health controller may be configured to receive multi-variate sensor signals indicative of a respective reference value at least one head parameter, wherein the respective reference value is based in part on at least one initial measurement of parameters of the head obtained at a first time, determine a respective predicted current value based at least in part on a respective fixed-drift model and the multi-variate sensor signals, determine a respective actual current value that is based at least in part on at least one current measurement of the head obtained at a second time later than the first time, determine a health status for the head, and store the health status in memory.

In an optical disc apparatus that records and reproduces data onto and from an optical disc in units of predetermined block, an information divider divides the data so as to reduce an amount of the data included in each of blocks when a recording state of the optical disc does not satisfy a predetermined criterion, and reproduces recording data in units of the block by adding sub-information including a value indicating the amount of the data included in each of the blocks. An error-correction encoder circuit encodes the recording data in a first error-correction code format, and a recorder converts encoded recording data into a recording signal, and records the recording signal onto the optical disc. A quality evaluator circuit produces an evaluation value indicating a recording quality based on a result of reproducing the recording signal recorded on the optical disc.

In general, techniques are described for monitoring health of a head in a magnetic data storage drive. A health controller may be configured to receive multi-variate sensor signals indicative of a respective reference value at least one head parameter, wherein the respective reference value is based in part on at least one initial measurement of parameters of the head obtained at a first time, determine a respective predicted current value based at least in part on a respective fixed-drift model and the multi-variate sensor signals, determine a respective actual current value that is based at least in part on at least one current measurement of the head obtained at a second time later than the first time, determine a health status for the head, and store the health status in memory.

Techniques for verifying a magnetic tape are disclosed. The techniques include obtaining a position signal generated by reading a magnetic tape using a stationary tape head. Next, a simulated current for adjusting a position of the tape head to follow a track on the magnetic tape is updated using the position signal. The simulated current is then compared to one or more saturation limits to generate a verification result for a servo pattern on the magnetic tape, wherein the verification result classifies the magnetic tape as usable or unusable. Finally, the verification result is outputted for use in managing subsequent use of the magnetic tape.