A data storage device is disclosed comprising at least one head configured to access a magnetic tape comprising a plurality of servo frames each comprising a plurality of servo bursts. A first servo burst is read using the head to generate a read signal which is sampled to generate signal samples. A first matched filter matched to the first servo burst is used to generate filtered samples in response to the signal samples, and at least part of the filtered samples are interpolated to generate interpolated samples. The interpolated samples are processed to generate a position error signal (PES), and a position of the head relative to the magnetic tape is controlled based on the PES.

A data storage device is disclosed comprising at least one head configured to access a magnetic tape comprising a plurality of servo frames each comprising an A servo burst, a B servo burst, a C servo burst, and a D servo burst. The A servo burst in a first servo frame is read using the head to generate a first read signal which is sampled to generate first signal samples. A first matched filter matched to the A servo burst filters the first signal samples to generate first filtered samples within a first burst window, and the first burst window is updated based on the first filtered samples. The first filtered samples within the first burst window are processed to generate a position error signal (PES), and a position of the head is controlled relative to the magnetic tape based on the PES.

A data storage device is disclosed comprising a first plurality of heads actuated over a first subset of disk surfaces by a first servo control loop comprising a first coarse actuator and a first fine actuator, and a second plurality of heads actuated over a second subset of the disk surfaces by a second servo control loop comprising a second coarse actuator and a second fine actuator. A plurality of access commands are received, wherein each access command is associated with one of the heads. While executing a first access command using the first servo control loop, a disturbance is ramped while injecting the disturbance into the second servo control loop, and the second fine actuator is calibrated based on the disturbance.

According to one embodiment, a magnetic disk device includes a disk having a first sector including first servo data, first user data, and first correction information used to correct a data error, a head that writes data to the disk and that reads data from the disk, and a controller that changes, according to a first defect length of a defect generated in the first sector in a circumferential direction of the disk, a first sector length of the first sector in the circumferential direction.

There is provided a magnetic recording medium of which a dimensional change due to a change in a temperature/humidity environment is small. The magnetic recording medium is a magnetic recording medium having a tape-like shape and having an average thickness of 5.3 μm or less. The magnetic recording medium includes a substrate and a magnetic layer provided on the substrate. An environmental relative humidity, in which a temperature expansion coefficient of the magnetic recording medium is 6.0 ppm/° C. or more and 8.0 ppm/° C. or less, ranges between 10% RH and 80% RH.

There is provided a magnetic recording medium of which a dimensional change due to a change in a temperature/humidity environment is small. The magnetic recording medium is a magnetic recording medium having a tape-like shape and having an average thickness of 5.3 μm or less. The magnetic recording medium includes a substrate and a magnetic layer provided on the substrate. An environmental relative humidity, in which a temperature expansion coefficient of the magnetic recording medium is 6.0 ppm/° C. or more and 8.0 ppm/° C. or less, ranges between 10% RH and 80% RH.

In a disk drive, when an off-track error occurs during a sequential disk access operation that spans multiple contiguous data tracks, efficient recovery is performed. In an embodiment, the disk access operation (e.g., reading from or writing to a disk) is attempted for all sectors of the sequential disk access operation. The disk access operation is then attempted again for sectors associated with any off-track errors that occurred during the disk access operation. In another embodiment, when an off-track error occurs during a sequential write operation in a shingled magnetic recording drive, the data originally targeted to be written to a first portion is written to a second portion of the data track that follows the first portion. Since no additional revolutions of the disk are needed for data associated with the sequential write operation to be written to the disk.

According to one embodiment, a magnetic disk device including a disk, a head, and a controller configured to, when writing a first servo sector, a second servo sector, and a third servo sector in the order described according to a second route varying in a radial direction of the disk with respect to a first route, adjust first timing used to write the second servo sector next to the first servo sector, and adjust second timing used to write the third servo sector next to the second servo sector.

In a two-dimensional magnetic recording (TDMR) system, a first finite impulse response (FIR) filter processes data read from a track of a magnetic medium by a first head using first filter tap values determined a priori independently of a second head. A second FIR filter processes data read from a track by the second head using second filter tap values determined a priori independently of the first head. A read channel module generates an output based on outputs of the first and second FIR filters.

The present disclosure generally relates to a tape drive comprising a tape head and control circuitry. The tape head comprises a plurality of data elements, each data element including a write transducer and a read transducer. The control circuitry is configured to control the tape head to write at least three different frequency preamble tones prior to writing data to data tracks of a tape. A different preamble tone is written to adjacent data tracks of the tape. The data elements of the tape head are each configured to read one or more preamble tones prior to writing data to or reading data from the tape. The control circuitry is then configured to extract a signal content from each preamble tone read by each data element, and determine an optimized positioning for the tape head with respect to the tape to reduce alignment errors.