Systems and methods for maximizing shingled magnetic recording (SMR) drive capacity are described. In one embodiment, the SMR drive may include a main store to store user-accessible data, a media cache and media scratchpad to store internal data temporarily for internal operations, and a storage controller to process read and write requests. In some cases, the main store comprises a shingled media partition and an unshingled media partition. The storage controller may designate one or more data tracks from the shingled media partition as temporary data track guard bands. In some embodiments, a track range is selected based at least in part on at least one of an amount of data in the media cache, a size of the new data in the media cache, and an association between the new data in the media cache and data currently stored within the selected track range.

An offset from track center of a writer that is writing to a track of a magnetic recording medium is determined. A write current applied to a write coil of the writer is adjusted to compensate for the offset. The adjusting of the write current affects a width of the track.

A storage device includes read circuitry having a read head having a detector that outputs signals representing data from a first track and an adjacent track. The read head is subject to off-track excursions during which the read head detects signals from both the first track and an adjacent track. Data on each track includes a preamble including a repeating pattern. The repeating pattern in any first track is orthogonal to the repeating pattern in any track adjacent to the first track. The read circuitry also includes respective Discrete Fourier Transform circuits to identify components in the signals corresponding to respective frequencies characteristic of the repeating pattern on the first track and the repeating pattern on the second track, and computation circuitry to determine from the components a ratio by which the read head is off-track. Corresponding methods are provided for operating such a storage device and for reading data.

Method and apparatus for recovering user data from a rotatable data recording medium. In some embodiments, a moveable read element detects at least one uncorrectable read error in user data stored in a data sector arranged along a concentric track. A read retry operation is carried out to recover the user data by radially advancing the moveable read element from a first offset value to a different second offset value with respect to the track in accordance with a trajectory profile while transducing the user data from the data sector. This allows data that are variably overwritten (encroached upon) by different radial amounts from an adjacent track to be recovered.

A method includes a processing module receiving data to store and determining error coding dispersal storage function parameters based on an error profile of one or more hard drives. The method continues with the processing module encoding at least a portion of the data in accordance with the error coding dispersal storage function parameters to produce a set of data slices. The method continues with the processing module defining addressable storage sectors within the one or more hard drives based on a number of data slices within the set of data slices to produce a set of addressable storage sectors. The method continues with the processing module storing data slices of the set of data slices in corresponding addressable storage sectors of the set of addressable storage sectors.

According to one embodiment, a magnetic disk device includes a magnetic recording medium, a head including a recording magnetic pole, a spin torque oscillator provided near the recording magnetic pole, and a coil which excites the recording magnetic pole, a first current supply which supplies the coil with a first current corresponding to write data, a detector which detects a first signal corresponding to the write data, and outputs a second signal in accordance with the first signal, and a second power supply which varies, in accordance with the second signal, a second current supplied to the spin torque oscillator.

An information recording medium (10) including a first region (11) in which medium identification information has been recorded, a data region (13), and a second region (12) which is positioned between the first region (11) and the data region (13) and in which control information has been recorded, in which an area of the first region (11) is greater than an area of the second region (12) in size.

Provided herein is a method including forming a data zone guiding pattern and forming a servo zone guiding pattern. A servo pattern and a data pattern are simultaneously formed. Directed self-assembly of block copolymers is guided by the data zone guiding pattern and the servo zone guiding pattern.

According to an embodiment, tracks on a magnetic disk each include a long-distance sector having a length in the circumferential direction covering two or more servo sectors. A controller executes an acquisition operation to acquire one or more evaluation amounts on the basis of a track pitch in each of the two or more servo sectors included in a portion adjacent to the long-distance sector. The controller executes a protection operation to protect data of an adjacent track in a case where a total value of the one or more evaluation amounts exceeds a first threshold value.

Improved tools and techniques for configuring a write head of a hard disk drive and/or for writing data to a hard disk drive. The write surface of a disk in the hard disk drive can be divided into multiple logical zones, with different interleave sizes for each zone. This scheme can meet latency requirements for regions closer to the center of the write surface while providing for better error rate performance in regions further away from the center of the write surface.