G11B20/12

SHINGLED MAGNETIC RECORDING RAID SCHEME
20170352375 · 2017-12-07 ·

A method for recording parity data of data stripes within shingled media recording bands in a redundant array of independent disks can be accomplished using a plurality of shingled media recording (SMR) hard disk drives (HDD) each with a plurality of shingled data bands. A data stream received from a host computer system is sequentially stored to a plurality of block segments in successive order, one stripe at a time successively. Each of the shingled data bands possess n data blocks (or multiple data blocks that are grouped together as a data unit) that are successively ordered, each corresponding successive data block from all of the SMR HDDs defines a data stripe, accordingly n data blocks in each SMR HDD defines n stripes across the shingled data bands. A transaction group sync triggers a halt to writing the data stream. The rest of the data stripe is written with fill bits. Parity data is written to a parity drive in one or more SMR parity blocks that correspond in size and sequence to the data blocks in the data stripes possessing the first data stream and any of the fill bits.

CACHING SYSTEMS AND METHODS FOR HARD DISK DRIVES AND HYBRID DRIVES
20170344276 · 2017-11-30 ·

A system includes a read/write module and a caching module. The read/write module is configured to access a first portion of a recording surface of a rotating storage device. Data is stored on the first portion of the recording surface of the rotating storage device at a first density. The caching module is configured to cache data on a second portion of the recording surface of the rotating storage device at a second density. The second portion of the recording surface of the rotating storage device is separate from the first portion of the recording surface of the rotating storage device. The second density is less than the first density.

Method for playing back information recording medium

An optical disk (100) of the present invention includes (i) a medium information region (101) (a) in which type identification information is recorded by recesses and/or protrusions which are formed by a given modulation method and whose lengths are longer than a length of an optical system resolution limit of a playback device and (b) in which first address information is recorded in a first address data format and (ii) a data region (102) (a) in which content data is recorded by recesses and/or protrusions which are formed by the given modulation method and which include a recess and/or a protrusion whose length is shorter than the length of the optical system resolution limit and (b) in which second address information is recorded in a second address data format.

Scalable storage device

Implementations described and claimed herein provide a high-capacity, high-bandwidth scalable storage device. The scalable storage device includes a layer stack including at least one memory layer and at least one optical control layer positioned adjacent to the memory layer. The memory layer includes a plurality of memory cells and the optical control layer is adapted to receive optically-encoded read/write signals and to effect read and write operations to the plurality of memory cells through an electrical interface.

Magnetic disk device and write processing method

According to one embodiment, a magnetic disk device includes a disk including a normal recording region written in a normal recording and a shingled recording region written in a shingled recording, a head including a write head and a plurality of read heads, the head moving on the disk by rotation about a rotation axis, and a controller which selects and executes the normal recording and the shingled recording, wherein a first minimum value of a cross track interval in the radial direction of the disk between two read heads in the plurality of read heads in the normal recording region is smaller than a first maximum value of the cross track interval in the shingled recording region.

Magnetic disk device and read/write processing method

According to one embodiment, a magnetic disk device includes a disk, a head, and a controller setting a rewrite threshold value for executing a rewrite process of different tracks in a first sector group including at least one first sector continuous from a first parity sector in which error correction processing in units of tracks is executable based on the first parity sector and including the first parity sector, and a second sector group including at least one second sector continuous in which the error correction processing in units of tracks is unexecutable, and rewriting the first sector group and the second sector group with different frequencies.

Writing adjacent tracks with different widths by varying fly height of a recording head

First and second nominal head-to-media spacings of a magnetic recording head are determined that result in tracks being written to a magnetic recording medium at respective narrower and wider tracks widths. Three or more adjacent tracks of user data are written to the magnetic recording medium using one of the first and second nominal head-to-media spacings so that the adjacent tracks alternate between the narrower and wider track widths.

HEAT-ASSISTED SHINGLED MAGNETIC RECORDING WITH VARIABLE TRACK WIDTHS
20170330591 · 2017-11-16 ·

A storage device includes a storage controller configured to operate a heat-assisted magnetic recording head to write data to a band of consecutive data tracks in a consecutive track order while selectively alternating a power level of the heat source when writing to some data tracks of the band.

Magnetic disk device capable of correcting servo demodulation position

According to one embodiment, a magnetic disk device includes a disk including two first servo sectors and at least a second servo sector, a head, and a controller, wherein the first servo sector includes burst data and a first data pattern written before the circumferential direction of the burst data, the second servo sector includes the burst data, the first data pattern, and a second data pattern written after the circumferential direction of the burst data, a first frequency of the first data pattern is different from a second frequency of the second data pattern, and a first length of the first data pattern is different from a second length of the second data pattern.

Recording and reproducing device for reconstructing user data

A recording/reproducing device and a recording/reproducing method, which are capable of improving reliability of data while securing compatibility with a file format employed in a recording medium are provided. Provided is a reconstruction method of reproduction data acquired from a reproducing device that reproduces data from a recording medium in which the data is recorded, performs error correction using a second error correction code specified in a file format employed in the recording medium, and outputs reproduction data, and the reconstruction method of the reproduction data includes obtaining reproduction data from the reproducing device, reading a first error correction code different from the second error correction code from the reproduction data, and performing error correction on the reproduction data using the first error correction code and reconstructing user data.