Western Digital Technologies, Inc.

Burlywood, Inc.

Micron Technology Incorporated

Akonia Holographics LLC

David Christopher Pruett

Marcus A Carlson

Tod Roland Earhart

Srinivas Neppalli

Amy Lee Wohlschlegel

John Foister Murphy

Kevin Darveau Landin

Nathan Koch

Will Allan Loechel

Christopher Bergman

John William Slattery

Erik Habbinga

William Henry Radke

Mark R Ayres

Kenneth E Anderson

Nicholas M Warner

David M Hamilton

Raymond Yu

Edoardo Daelli

Abedon Madril

Laszlo Borbely

A method of operating a telemetry capture system within a data storage system comprising storage devices is provided. The method includes generating a telemetry packet, and providing the telemetry packet to one or more taps via a telemetry path independent of data and control paths within the storage devices. The method also includes capturing the telemetry packet in one or more of the taps, and generating real-time telemetry data based at least on the telemetry packet.

Telemetry capture system for storage systems

A storage controller is provided. The storage controller includes a host interface, a drive interface, and a quality of service control module coupled with the host interface and the drive interface. The QoS module includes read and write queues for each data stream, each queue associated with corresponding token buckets, and an arbiter, configured to receive requests from the read and write queues, and to service the read and write queues in an order at least partially determined by a quantity of tokens in each token bucket. The QoS module also includes a quality of service measurement module, configured to measure quality of service levels for each of the read and write queues, and a bandwidth allocation manager, configured to allocate tokens to each token bucket at a rate corresponding to the service level agreements and the measured quality of service level for each of the read and write queues.

Drive-level internal quality of service

A method of operating a storage controller is provided. The method includes receiving data transferred by a host for storage in a target partition of a storage media, and detecting properties of the data. The method also includes establishing one or more inferred partitions on the storage media based at least on the properties of the data, and based at least on the properties of the data, sorting subsets of the data for storage within the target partition and the one or more inferred partitions.

Write stream separation into multiple partitions

A method of operating a storage controller is provided. The method includes determining encoded data to be written to a storage media by applying at least an initial encoding comprising a first error correcting code type and a subsequent encoding comprising a second error correcting code type. The method further includes writing the encoded data to the storage media, and responsive to reading the encoded data from the storage media, processing the encoded data into primary decoded data using one or more primary decoders employing the second error correcting code type and detecting when data errors arise in the decoded data. The method also includes based at least on detecting one or more data errors in the decoded data, processing the encoded data into secondary decoded data using one or more secondary decoders employing the first error correcting code type.

Enhanced data storage with concatenated inner and outer error correction codes

Methods and devices for coherent holographic data channel techniques. Coherent techniques for data detection generally include homodyne and heterodyne detection. Techniques for quadrature homodyne detection, resampling quadrature homodyne detection, n-rature homodyne detection, and spatial wavefront demodulation. Coherent detection techniques in turn enable coherent channel modulation techniques such as phase modulation (including binary phase shift keying, or BPSK; phase quadrature holographic multiplexing, or QPSK; and quadrature amplitude modulation, or QAM). Coherent detection may also enable or improve the performance of other channel techniques such as partial response maximum likelihood (PRML), the various classes of extended PRML, and of noise-predictive maximum likelihood (NPML) detection.

Methods and apparatus for coherent holographic data channels

Multiple engine sequencers in memory interfaces are disclosed. Individual sequencer engines of multiple engine sequencers perform at least portions of their respective operations in parallel with other individual sequencer engine operations performed in the memory interface. In at least one embodiment, sequencer engine operations are performed at least partially concurrently with other sequencer engine operations in the memory interface.

Multiple engine sequencer

Managing data objects in a Data Storage Device (DSD) including a disk and a volatile memory for storing data. A data object is written from the volatile memory in a data object zone of the disk of the DSD. At least one most recent version of a previously written data object is rewritten in the data object zone so that an earlier version of the data object written from the volatile memory does not interrupt a contiguous plurality of most recent versions of data objects stored in the data object zone.

Management of data objects in a data object zone

A disk drive comprising a rotatable disk, a head actuated over the disk, and a controller is disclosed. The controller is configured to write data on the disk using the head, to store logical-to-physical mapping information for data already written on the disk in a circular buffer as the data is written on the disk, and to write a plurality of metadata files on the disk using the head, wherein the plurality of metadata files are interspersed with the data on the disk and each of the metadata files includes contents of the circular buffer at a time the metadata file is written on the disk.

Writing metadata files on a disk

A disk drive is disclosed that utilizes an additional address mapping layer between logical addresses used by a host system and physical locations in the disk drive. Physical locations configured to store metadata information can be excluded from the additional address mapping layer. As a result, a reduced size translation table can be maintained by the disk drive. Improved performance, reduced costs, and improved security can thereby be attained.

Disk drive with reduced-size translation table

A data storage device is disclosed including a non-volatile media having a plurality of physical locations for storing user data, each physical location associated with a logical block address (LBA), a translation table having a plurality of entries, each entry having a mapping of one or more LBAs to a corresponding number of physical locations on the non-volatile media. The data storage device further includes control circuitry that divides the translation table into a plurality of segments, each segment including a group of entries corresponding to a range of LBAs, determines a first score for each segment using a first metric, and selects a segment for defragmentation by utilizing the first score for each segment.

Method for selective defragmentation in a data storage device

A disk drive is disclosed comprising a head actuated over a rotatable disk. A write operation is processed to write data on the disk using the head, wherein prior to writing the data on the disk, logical-to-physical mapping information is stored in a circular buffer, wherein the logical-to-physical mapping information identifies locations on the disk to write the data. A plurality of metadata files are written on the disk using the head, wherein the plurality of metadata files are interspersed with the data on the disk and each of the metadata files includes contents of the circular buffer at a time the metadata file is written on the disk. When the write operation is aborted, the logical-to-physical mapping information in the circular buffer is modified to identify the locations on the disk actually written.

Disk drive modifying metadata cached in a circular buffer when a write operation is aborted

The present invention relates to methods and systems for efficiently accessing data stored on a data storage device. The data storage device may comprise various types of media, such as shingled media and non-shingled media, alone or in combination. The data storage device may employ a logical block address space for specifying location of blocks of data stored on the data storage device. In addition, pre-determined sequential ranges of logical block addresses are grouped together and may be referenced collectively. In some embodiments, each type of media type may be partitioned into sections for containing different sizes of collections. Each collection of logical block addresses may be allocated to an arbitrary logical slot. Each logical slot may then be linked to a physical slot on the data storage device.

Method for file based shingled data storage utilizing multiple media types

A disk drive subsystem is disclosed that implements a process for metadata recovery. Certain embodiments relate to recovery of metadata containing information indicating the physical locations in the disk drive in which host data is stored. In an embodiment, the metadata to be recovered is disposed in sequence with, or in physical association with host data that it describes. Recovery is accomplished by identifying metadata that is valid, but is absent from one or more translation tables containing translation information. Metadata portion can include one or more identifiers that are sequentially related to identifiers included in one or more other metadata portions. Performance improvements can thereby be attained.

Growing community of inventors

Longmont, CO, United States of America

David Christopher Pruett