Various illustrative aspects are directed to a data storage device comprising data tracks N and N−1, and one or more processing devices, configured to measure signal to noise ratio (SNR) metrics for corresponding sectors of at least one of the data tracks N−1 and N, where the measuring is based at least in part on reading one or more of the data tracks N and N−1 using one or more read offsets, estimate a position of at least one of the data tracks based on measuring the one or more SNR metrics, and reconstruct one or more of risk values for at least a portion of the data track N−1 based on the one or more SNR metrics for the data track N−1, and a position error signal (PES) for at least one of the data tracks N−1 and N based on the corresponding estimated positions.

A method for positioning a magnetic head having first and second read sensors and one write head includes: while the magnetic head is at a first position relative to a disk medium, reading first magnetic servo information written on a first surface of the disk medium, with the first read sensor, and reading second magnetic servo information written on the first surface of the disk medium with the second read sensor; determining a position error of the magnetic head based on the first and second magnetic servo information; and repositioning the magnetic head to a second position relative to the disk medium to compensate for the determined position error of the magnetic head.

According to one embodiment, a magnetic disk device comprising a magnetic disk, a magnetic head, and a controller that registers an address and a positioning error, determines whether or not a positioning error of a second sector that is two tracks ahead in a radial direction of a first sector to which a data is written is registered, and when the positioning error of the second sector is registered, sets a first threshold that allows a write operation for a positioning error of the first sector based on the positioning error of the second sector, and determines whether or not the positioning error of the first sector exceeds the first threshold, and stops the write operation when the positioning error of the first sector exceeds the first threshold.

A data storage device comprises a disk having a plurality of data tracks and a plurality of servo wedges wherein the plurality of servo wedges comprise a plurality of wedge repeatable runout (WRRO) fields configured to store a plurality of WRRO compensation values in connection with the plurality of data tracks. The data storage device may also include a read/write head configured to be actuated over the disk, and a controller configured to gather position error signal (PES) data needed for computation of the WRRO compensation values during a field operation of the data storage device. The data storage device may be further configured to adjust a position of the read/write head based on the WRRO compensation values.

Various illustrative aspects are directed to a data storage device comprising data tracks N and N−1, and one or more processing devices, configured to measure signal to noise ratio (SNR) metrics for corresponding sectors of at least one of the data tracks N−1 and N, where the measuring is based at least in part on reading one or more of the data tracks N and N−1 using one or more read offsets, estimate a position of at least one of the data tracks based on measuring the one or more SNR metrics, and reconstruct one or more of risk values for at least a portion of the data track N−1 based on the one or more SNR metrics for the data track N−1, and a position error signal (PES) for at least one of the data tracks N−1 and N based on the corresponding estimated positions.

According to one embodiment, an operating condition determining device includes a memory, and a processer. The memory is configured to store a plurality of classifications relating to information corresponding to a vibration state of a magnetic recording/reproducing device, and a plurality of setting parameter sets relating to an operation of the magnetic recording/reproducing device. The setting parameter sets correspond to the classifications. The processer is configured to acquire a first data. The first data includes information of the vibration state of the magnetic recording/reproducing device. The information is measured. The processer is configured to acquire one of the setting parameter sets from the memory. The one of the setting parameter sets corresponds to one of the classifications corresponding to the first data.

A controller for a magnetic disk device acquires a reproduction signal of servo burst data while moving a magnetic head along data tracks that intersect servo tracks at a plurality of points. The controller acquires correction values for correcting repeatable runout on a per servo sector basis based on the reproduction signal. The correction values include a first correction value, which is a correction value for a servo sector at a position where the data track and the servo track are substantially parallel to each other and a second correction value, which is a correction value fora servo sector at a position where the data track and the servo track are not substantially parallel to each other. The controller adjusts the first correction value based on the second correction value, and writes the correction values including the adjusted first correction value onto a magnetic disk.

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.

A method for writing repeatable run-out data, representing a recurring contribution to position error, to a rotating constant-density magnetic storage medium, includes repeating, for each respective track at a respective radius of the constant-density magnetic storage medium, (1) determining a respective track pattern frequency based on track location and desired data density, (2) locating a position in a respective servo wedge on the respective track based on servo sync mark detection, (3) writing the repeatable run-out data to the respective servo wedge at a time delay, from the location of the position in the respective servo wedge, that is inversely proportional to the respective radius, to achieve a predetermined offset, and (4) repeating the determining, the locating and the writing for each servo wedge on the respective track of the constant-density magnetic storage medium.

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, wherein each servo burst comprises a plurality of servo stripes. The servo stripes in a first servo burst are read using the head to generate a first read signal that is processed using a first matched filter matched to the first servo burst in order to generate an average time stamp for the servo stripes in the first servo burst. A position error signal (PES) is generated based on the average time stamp of the first servo burst, and the head is positioned relative to the magnetic tape based on the PES.