At least a portion of a first servo mark is read using a first read head during a rotation of a disk, the rotation comprising no more than 360 degrees. At least a portion of a second servo mark is read using a second read head during the rotation of the disk. Tracking positions of the first read head and the second read head are determined during the rotation based on reading the first servo mark and the second servo mark.

At least a portion of a first servo mark is read using a first read head during a rotation of a disk, the rotation comprising no more than 360 degrees. At least a portion of a second servo mark is read using a second read head during the rotation of the disk. Tracking positions of the first read head and the second read head are determined during the rotation based on reading the first servo mark and the second servo mark.

Analog-to-digital conversion circuitry for generating a digital output signal is disclosed comprising a sample-and-hold circuit comprising an adjustable sample capacitor for coupling to an analog input signal during a sample phase, and an analog-to-digital converter (ADC) coupled to an output of the sample-and-hold circuit during a hold phase. In order to compensate in real-time for an increase in an amplitude of the input signal, a capacitance of the sample capacitor is decreased by an attenuation factor, and an output of the ADC is multiplied by an inverse of the attenuation factor to generate the digital output signal.

A system includes a driver and a controller. The driver is configured to output a signal to a preamplifier of a heat source based on a thermal compensation value to cause the heat source to heat a spot on a storage medium. The controller is configured to adjust the thermal compensation value based on a duration for which the heat source is in an active or inactive operational state. The thermal compensation value is indicative of a history of durations that the heat source was in the active or inactive operational state.

A data storage device is disclosed comprising a head actuated over a disk, and a two-dimensional (2D) equalizer comprising a plurality of coefficients. A plurality of stored coefficients are accessed based on a first off-track offset of the head in order to first initialize the coefficients of the 2D equalizer, and then the coefficients of the 2D equalizer are first adapted based at least on a first read signal to generate first adapted coefficients. The plurality of stored coefficients are accessed based on a second off-track offset of the head in order to second initialize the coefficients of the 2D equalizer, and then the coefficients of the 2D equalizer are second adapted based at least on the first read signal to generate second adapted coefficients.

This disclosure is related to media cache cleaning based on workload. In some examples, a read-modify-write (RMW) operation may merge new data with existing data and the merge may be interrupted without losing the amount of work already processed. This can be particularly useful for shingled magnetic recording (SMR) systems that utilize a large cache, such as a media cache, that can accumulate many entries that might need to be merged with existing data. An RMW operation can be interrupted such that a host command does not timeout.

According to one embodiment, a disk device includes a recording medium, a first magnetic head, a first wiring member, a flexible printed circuit board, and a wire. The first wiring member is electrically connected to the first magnetic head. The flexible printed circuit board includes a surface, a first fixed part fixed to a first component, and a second fixed part fixed to a second component, and is electrically connected to the first magnetic head through the first wiring member. The wire on the flexible printed circuit board extends along the surface such that the wire extends between the first fixed part and the second fixed part in a direction intersecting at an angle of larger than 45 degrees and not larger than 90 degrees with an extending direction of a virtual shortest line that connects the first fixed part to the second fixed part along the surface.

A storage array includes a plurality of hard disks, where each of the hard disks is divided into a plurality of chunks, and a plurality of chunks of different hard disks form a chunk group using a redundancy algorithm. The storage array obtains fault information of a faulty area in a first hard disk, and determines a faulty chunk storing the lost data according to the fault information. The storage array recovers the data in the faulty chunk using another chunk in a chunk group to which the faulty chunk belongs and stores the recovered data in a recovered chunk. The recovered chunk is located in a second hard disk which is not a hard disk for forming the chunk group.

This disclosure describes codes and techniques for magnetic recording. The coding schemes decrease bit error rates by decreasing total transitions in the encoded binary data compared to conventional codes. Additionally, instead of relying on a single coding scheme, an encoder and decoder are configured to switch between different coding schemes. By so doing, a variety of the coding schemes allows the encoded binary data to have a smaller bit error rate than a single coding scheme and have a maximum run-length less than or equal to a maximum run-length limitation of a magnetic disk.

This disclosure describes codes and techniques for magnetic recording. The coding schemes decrease bit error rates by decreasing total transitions in the encoded binary data compared to conventional codes. Additionally, instead of relying on a single coding scheme, an encoder and decoder are configured to switch between different coding schemes. By so doing, a variety of the coding schemes allows the encoded binary data to have a smaller bit error rate than a single coding scheme and have a maximum run-length less than or equal to a maximum run-length limitation of a magnetic disk.