A heat-assisted recording head is moved onto a ramp such that the recording head is thermally isolated from a moving disk. A heating device is activated on the recording head to cause the recording head to obtain a high temperature that is not obtainable when proximate to the moving disk. The recording head is moved over the moving disk such that the recording head reaches an operating temperature that is below the high temperature. One or more temperatures between the high temperature and the operational temperature are determined at which a laser of the recording head experiences mode-hopping. The one or more temperatures are stored and accessed by a controller to mitigate mode hopes during an operation of the recording head.

The disclosed technology provides a method that reduces time to recover in storage systems. In one implementation, the method comprises entering an idle status, determining if there is an incomplete band update operation, invalidating a media scratch pad (MSP) by clearing headers responsive to determining there is no incomplete band update operation, performing a power cycle, reading an MSP header, and determining if an MSP header is valid. If a rude power cycle occurs and the MSP header is determined to be valid, an MSP is examined, and restored if required. If a safe power cycle occurs, an MSP restore operation is not required, reducing time to recover.

Systems and methods are disclosed for error recovery in a digital data channel. In an error recovery approach when the hardware fails to recover a sector, the sample for that sector can be saved along with a metric measure that indicates the quality of the sample. This process can begin from a first on-the-fly receiving and decoding of data. During each step of error recovery, a retry attempt may either use samples obtained during a new decoding attempt or may use a sample, or a combination of samples, having the best metric from an earlier attempt, or a combination of earlier attempts, to perform the recovery during a current retry recovery attempt.

According to one embodiment, a disk device includes a disk, a head that performs data read/write processing on a recording region of the disk, a controller that performs a media scan processing for detecting the presence or absence of a defect in a sector in the recording region of the disk in track unit. When the controller performs the media scan processing on a first sector and a second sector arranged in the track, and a third sector arranged between the first sector and the second sector, the controller performs skip processing in which the controller scans the first sector and the second sector, and does not scan the third sector.

A data storage device is disclosed comprising a head actuated over a disk. A first plurality of codewords and corresponding parity sector are generated, and a second plurality of codewords and corresponding parity sector are generated. The first and second plurality of codewords are written to the disk, and during a read of the first and second set of codewords, M codeword locations within the data track that are unrecoverable are saved, and N codeword locations out of the M codeword locations are selected based on a quality metric of the read. The N codewords are reread from the data track at the N codeword locations and reliability metrics associated with the N codewords are saved. The saved reliability metrics are updated using at least one of the first parity sector or the second parity sector.

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 a first data segment of a first data track, and second data is written to a second data segment of a second data track. After writing the second data, a quality metric is measured for at least two off-track offsets of the first data segment. A track pitch is estimated between the first data segment and the second data segment based on the quality metrics, and a track trajectory is generated for the second data segment based on the estimated track pitch. Third data is written to the second data segment based on the track trajectory.

A magnetic disk device includes a magnetic disk and a control circuit. The magnetic disk includes a first area where writing is performed in a manner such that a newly written track partially overlaps a previously written adjacent track. The control circuit is configured to specify a range of a second track, which is to be overlapped as a result of writing first data to a first track, write second data written in the specified range of the second track to a saving area prior to writing the first data to the first track, write the first data to the first track, and verify the second data in the second track after writing the first data to the first track.

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 tape drive system for ensuring tape data integrity by tape surface inspection, the tape drive system being configured for reading and writing data from/to a magnetic tape, is provided. The tape drive system includes a laser inspection unit comprising a sender and a receiver integrated into the tape drive system, wherein the laser inspection unit configured for recognizing a tape defect by scanning the magnetic tape when the tape drive system is in operation. The tape drive system includes a read/write head configured for acting together with the laser inspection unit as sensors for providing sensor data during a read/write operation of the tape drive system, a communication link between the sensors and a controller unit for exchanging sensor data. The controller is configured for evaluating sensor data and for triggering predefined actions based on the respective evaluation results such that the tape data integrity is ensured.

A method includes moving a heat-assisted magnetic recording (HAMR) slider relative to a magnetic recording medium. The slider comprises a writer, a writer heater, and a near-field transducer (NFT). For each of a plurality of different head-to media spacings a test tone is written to a track of the medium, the test tone is read and a Discrete Fourier Transform (DFT) of an amplitude of the read test tone is captured. A first DFT curve is generated at a beginning of writing the test tones. A second DFT curve is generated at a saturated state of writing the test tones. An amount of horizontal shift between the first and second DFT curves is computed. The amount of horizontal shift corresponding to writer heater power required to compensate for NFT clearance offset due to laser induced writer protrusion.