Abstract: A data storage device is disclosed comprising at least one head configured to access a magnetic tape. The head is used to write contiguously to the magnetic tape a first preamble, followed by a first sync mark, followed by symbols of a first data sector, followed by a second sync mark, followed by a second preamble, followed by a third sync mark, followed by symbols of a second data sector.

Abstract: A data storage device configured to access a magnetic tape is disclosed, wherein the data storage device comprises at least one head configured to access the magnetic tape. A first plurality of data blocks are encoded into a first plurality of ECC sub-blocks including a first ECC sub-block, and the first plurality of ECC sub-blocks are encoded into a first ECC super-block. The first ECC sub-block is written to the magnetic tape, and a write-verify of the first ECC sub-block is executed by reading the first ECC sub-block. When the write-verify passes, a second plurality of data blocks are encoded into a second ECC super-block, and when the write-verify fails, a third plurality of data blocks and the first ECC sub-block are encoded into the second ECC super-block, wherein the second ECC super-block is written to the magnetic tape.

Abstract: An external servo writer configured to write a plurality of embedded servo sectors on a magnetic tape to define a plurality of data tracks is disclosed. A first part of the plurality of embedded servo sectors is written while controlling an actuator to first move a head vertically along a width of the magnetic tape. A second part of the plurality of embedded servo sectors is written while controlling the actuator to second move the head vertically along the width of the magnetic tape.

Abstract: A data storage device is disclosed comprising at least one head configured to access a magnetic tape comprising a plurality of data tracks, wherein each data track comprises a plurality of data segments and a plurality of servo sectors. The head is used to read one of the servo sectors to generate a first read signal. The first read signal is processed to generate a position error signal (PES) of the head relative to the magnetic tape, wherein the head is positioned relative to the magnetic tape based on the PES. The head is used to read one of the data segments to generate a second read signal, wherein the second read signal is processed to detect user data recorded in the data segment.

Abstract: A data storage device is disclosed comprising at least one head configured to access a magnetic tape. Data is read from the magnetic tape to generate a read signal which is processed to decode a first M blocks of low density parity check (LDPC) type codewords using a LDPC type decoder. First un-converged codewords out of the first M blocks are decoded using a first M-blocks parity, and second un-converged codewords out of the first M blocks are decoded using an erasure code.

Abstract: A data storage device is disclosed wherein a first codeword is generated comprising first redundancy, and a second codeword is generated comprising second redundancy. At least part of the first codeword is written to a first data sector and a second data sector of a first data track on a disk, and at least part of the second codeword is written to a third data sector and a fourth data sector of the first data track different from the first data sector and the second data sector. When an anomaly is detected in the first data sector, first extended redundancy is generated over at least the first data sector and the second data sector of the first data track without generating second extended redundancy over the third data sector and the fourth data sector. Data is recovered from the first data sector based on the first extended redundancy.

Abstract: A data storage device is disclosed wherein a first codeword is generated comprising first redundancy, and a second codeword is generated comprising second redundancy. At least part of the first codeword is written to a first data sector and a second data sector of a first data track on a disk, and at least part of the second codeword is written to a third data sector and a fourth data sector of the first data track different from the first data sector and the second data sector. When an anomaly is detected in the first data sector, first extended redundancy is generated over at least the first data sector and the second data sector of the first data track without generating second extended redundancy over the third data sector and the fourth data sector. Data is recovered from the first data sector based on the first extended redundancy.

Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of tracks. A first codeword is generated comprising first redundancy, and first position information of the head relative to a first track is saved while writing the first codeword to the first track. A second codeword is generated comprising second redundancy, and second position information of the head relative to a second track is saved while writing the second codeword to the second track. Extended redundancy is generated for the first codeword based on the first and second position information, and the first codeword is recovered from the first track based on the extended redundancy generated for the first codeword.

Abstract: 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.

Abstract: A data storage device is disclosed comprising a head actuated over a disk. The head is positioned at a first radial location over the disk and at least part of a codeword on the disk is read to generate first signal samples. A first quality metric is generated for the first signal samples. The head is positioned at a second radial location over the disk different from the first radial location and at least part of the codeword is read to generate second signal samples. A second quality metric is generated for the second signal samples. A first subset of the first signal samples is combined with a second subset of the second signal samples based on the first and second quality metrics to generate a combined set of signal samples. An attempt is made to decode the codeword based on the combined set of signal samples.

Abstract: A data storage device is disclosed comprising a head actuated over a disk comprising a plurality of data tracks. Data is encoded into a first number of codewords, and the first number of codewords are interleave written to a first segment of a first data track. Data is encoded into a second number of codewords, and the second number of codewords are interleave written to a second segment of the first data track. The first number of codewords is different than the second number of codewords, and a size of the first segment is different than a size of the second segment.