According to one embodiment, a magnetic disk drive in the present embodiment includes a disk including tracks, each including servo sectors, a head, and a controller configured to acquire first correction data for repeatable runout occurring in a first direction, and second correction data different from the first correction data, to write the first correction data within a first permitted range in the first direction, to write the second correction data within a write permitted range including the first permitted range and a second permitted range in a second direction opposite to the first direction, to read at least one of the first correction data and the second correction data, and to correctly place the head.

A product according to one embodiment includes a magnetic recording tape having opposite ends and at least one servo track, a longitudinal axis of the magnetic recording tape being defined between the ends. The at least one servo track has a plurality of straight first magnetic bars, and a plurality of straight second magnetic bars spaced from the first magnetic bars. A width of each of the at least one servo track is defined in a direction perpendicular to the longitudinal axis of the magnetic recording tape between sides of the servo track. Lengths of the second magnetic bars between outermost ends thereof are less than 80% of the width of the associated servo track, straight portions of the second magnetic bars each having a longitudinal axis oriented substantially 90 degrees from the longitudinal axis of the magnetic recording tape.

The technology disclosed herein provides a method for generating an on-cylinder limit (OCLIM), the method including performing servo certification of a plurality of drives in a storage device to generate servo adaptive parameters (SAPs) by heads, generating a plurality of read adjust parameters (RAPs) by heads for the plurality of drives, generating an interim OCLIM value based on the SAPs by heads and RAPs by zones, and operating a disc drive write element using the interim OCLIM value.

According to one embodiment, a magnetic disk device includes a disk including a first sector arranged at a first radial position deviated from a target position in a radial direction by a first offset amount larger than a first threshold value, a head that writes data to the disk and reads data from the disk, and a controller that reads the first sector by arranging the head at a second radial position deviated from the target position by a second offset amount different from the first offset amount.

A tape-shaped magnetic recording medium includes a substrate; and a magnetic layer that is provided on the substrate and contains a magnetic powder. An average thickness of the magnetic layer is not more than 90 nm, an average aspect ratio of the magnetic powder is not less than 1.0 and not more than 3.0, the coercive force Hc1 in a vertical direction is not more than 3000 Oe, and the coercive force Hc1 in the vertical direction and a coercive force Hc2 in a longitudinal direction satisfy a relationship of Hc2/Hc1≤0.8.

The techniques described herein relate to methods, apparatus, and computer readable media configured to access multimedia data comprising a hierarchical track structure with a first track of a first sequence of temporally-related media units at a first level, and a second track at a second level comprising metadata specifying a temporal track derivation operation. The metadata includes a set of one or more operations to perform on the first track, each operation including a unit duration of the first sequence and a start unit in the first sequence. The temporal track derivation operation is performed on a set of media units comprising at least the first sequence, and includes applying the set of one or more operations to temporally modify the first sequence to generate second media data for the second track that includes a second sequence of temporally-related media units from the set of media units.

A data storage device is disclosed comprising a head actuated over a magnetic media. A write boost is configured to a first setting, and a first pattern of magnetic transitions is written to a first servo field of a servo sector on the magnetic media using the first setting for the write boost. The write boost is configured to a second setting different from the first setting, and the first pattern of magnetic transitions is written to a second servo field of the servo sector on the magnetic media using the second setting for the write boost.

A data storage device is disclosed comprising a head actuated over a magnetic media comprising a plurality of data tracks, wherein each data track comprises a plurality of data sectors. A first codeword is encoded, and the first codeword is written to multiple data sectors of a first data track including a first data sector. A second codeword is encoded, and at least part of the second codeword to is written to the multiple data sectors of a second data track adjacent the first data track including a second data sector adjacent the first data sector of the first data track. The first codeword is partially written to at least the first data sector of the first data track when the first data sector of the first data track is corrupted by writing the second codeword to the second data track.

There is provided a recording apparatus, a recording method, a reproduction apparatus, a reproduction method, a recording medium, an encoding apparatus, and a decoding apparatus which enable recording or reproduction to be easily implemented at high line density. User data is encoded into a multilevel edge code, and a multilevel code whose value changes in accordance with the multilevel edge code is recorded. The multilevel edge code is generated through state transition of a code generation model which includes a state representing the number of times that zero is consecutive corresponding to a number of ways of the number of times that zero is consecutive, which is the number of times that an edge of 0 is consecutive among edges representing a change amount from an immediately preceding value of the multilevel code of an ML value which is equal to or greater than 3, and which transitions to a state representing the number of times that zero is consecutive including 0 in a case where 0 is output, and transitions to a state representing that the number of times that zero is consecutive is 0 times in a case where one of 1 to ML−1 is output.

A derivation device is a device that derives a reading path by a reading element in a case where plural pieces of data to be read are read from a recording medium, and includes a first derivation unit that derives a value representing a recording density of the data for each of plural areas in which the plural pieces of the data to be read are recorded, and a second derivation unit that derives a path for sequentially reading the data as the reading path for an area in which the value representing the recording density is equal to or larger than a predetermined threshold value and derives the reading path according to a predetermined path determination method for an area in which the value representing the recording density is less than the threshold value.