International Business Machines Corporation

Lsi Corporation

Seagate Technology Incorporated

Carl E Forhan

Robert Edward Galbraith

Timothy B Lund

Adrian Cuenin Gerhard

Timothy W Swatosh

Michael Scott Hicken

Jessica M Gisi

Pamela Hempstead

Erich Franz Haratsch

George Mathew

Ming Jin

Jongseung Park

Bryan Holty

Daniel Frank Moertl

Timothy J Schimke

Mark Ish

Brian Eric Bakke

Jackson L Ellis

Leonid Baryudin

Alex G Tang

Jeffrey L Williams

Jeffrey Munsil

Paul Gary Reuland

Frederic Lawrence Huss

Randal Rysavy

Randy Reiter

Russell Paul VanDuine

John Paradise

Douglas David Prigge

Lawrence P Connoy

A method includes compressing input data to form compressed data and comparing a size of the compressed data to a maximum allowed size determined from a fixed sector size for a lower tier of the multi-tier storage system and a minimum pad length for a pad that is stored in the same sector as the compressed data when the compressed data is migrated to the lower tier. When the size of the compressed data is greater than the maximum allowed size, the input data is stored instead of the compressed data in an upper tier of the multi-tier storage system.

Fixed record media conversion with data compression and encryption

Apparatus and method for managing data in a hybrid data storage device. The device has a first non-volatile memory (NVM) of solid state memory cells arranged into a first set of garbage collection units (GCUs), and a second NVM as a rotatable data recording medium arranged into a second set of GCUs each comprising a plurality of shingled magnetic recording tracks. A control circuit combines a first group of logical block units (LBUs) stored in the first set of GCUs with a second group of LBUs stored in the second set of GCUs to form a combined group of LBUs arranged in sequential order by logical address. The control circuit streams the combined group of LBUs to a zone of shingled magnetic recording tracks in a selected one of the second set of GCUs. A combined media translation map identifies physical addresses in both the first and second NVMs.

Managing shingled magnetic recording (SMR) zones in a hybrid storage device

Described embodiments provide a method of cancelling inter-track interference (ITI) from one or more sectors read from a desired track of a storage medium. A road channel reads sectors in a desired track of the storage medium. A decoder of the read channel decodes the read sectors, and if the read sectors are incorrectly recovered from the storage medium, selected sectors of a first adjacent track and a second adjacent track are read. An ITI canceller of the read channel estimates ITI in the read sectors of the desired track corresponding to the selected sectors of each adjacent track and subtracts the estimated ITI of each adjacent track from the data for the sectors of the desired track, providing updated sector data. The ITI cancelled data is replayed to the decoder, which decodes the ITI cancelled data and provides the decoded ITI cancelled data as output of the read channel.

Storage media inter-track interference cancellation

Described embodiments provide a method of cancelling inter-track interference (ITI) from one or more sectors read from a desired track of a storage medium. A read channel reads sectors in a desired track of the storage medium. An iterative decoder of the read channel decodes the read sectors, and if the read sectors are incorrectly recovered from the storage medium, selected sectors of a first adjacent track are read. An ITI canceller of the read channel estimates ITI in the read sectors of the desired track corresponding to the selected sectors of the adjacent track and subtracts the estimated ITI of the adjacent track from the data for the sectors of the desired track, providing updated sector data. The ITI cancelled data is replayed to the iterative decoder, which decodes the ITI cancelled data and provides the decoded ITI cancelled data as output data of the read channel.

Described embodiments provide a media controller for processing a diagnostic request received from a diagnostic source. The received diagnostic request is parsed by a corresponding request handling module of the media controller, where each diagnostic source type has a corresponding request handling module. If the received diagnostic request requires allocation of buffer space, a common diagnostic handling module of the media controller allocates buffer space in a buffer for the received diagnostic request. The common diagnostic handling module is common for all diagnostic source types. The common diagnostic handling module provides the received diagnostic request to a corresponding one of a plurality of end diagnostic handling modules. The end diagnostic handling module performs the diagnostic tasks. If the received diagnostic request requires a transfer of data to the diagnostic source, the common diagnostic handling module performs the data transfer between the media controller and the diagnostic source.

Processing diagnostic requests for direct block access storage devices

Described embodiments provide a host subsystem that generates a host context corresponding to a received host data transfer request. A programmable sequencer generates one or more sequencer contexts based on the host context. Each of the sequencer contexts corresponds to at least part of the host data transfer request. The sequencer contexts are provided to a buffer subsystem of the media controller. For host read requests, the buffer subsystem retrieves the data associated with the sequencer contexts of the read request from a corresponding buffer or a storage media and transmits the data associated with the sequencer contexts to the host device. For host write requests, the buffer subsystem receives the data associated with the host context from the host device and stores the data associated with the sequencer contexts of the write request to a corresponding buffer or the storage media.

Processing host transfer requests for direct block access storage devices

Described embodiments provide a media controller that synchronizes data cached in a buffer and corresponding data stored in one or more sectors of a storage device. A buffer layer module of the media controller caches data transferred between the buffer and the storage device. One or more contiguous sectors are associated with one or more chunks. The buffer layer module updates a status corresponding to each chunk of the cached data and scans the status corresponding to a first chunk of cached data. If, based on the status, the first chunk of cached data is more recent than the corresponding data stored on the storage device, a media layer module synchronizes the data on the storage device with the cached data. The status corresponding to the group of one or more sectors is updated. The media layer module scans a next chunk of cached data, if present.

Cache synchronization for solid state disks

Described embodiments provide tracking and processing of commands received by a storage device. For each received command, the storage device determines one or more requested logical block addresses (LBAs), including a starting LBA and a length of one or more LBAs of the received command. The storage device determines whether command reordering is restricted. If command reordering is not restricted, the storage device processes the received commands. Otherwise, if command reordering is restricted, the storage device conflict checks each received command. If no conflict is detected, the storage device tracks and processes the received command. Otherwise, if a conflict is detected, the storage device queues the received command.

Command tracking for direct access block storage devices

Described embodiments provide a method of transferring, by a media controller, data associated with a host data transfer between a host device and a storage media. A buffer layer module of the media controller segments the host data transfer into one or more data transfer segments. Each data transfer segment corresponds to at least a portion of the data. The buffer layer module allocates a number of physical buffers to a virtual circular buffer for buffering the one or more data transfer segments. The buffer layer module transfers, by the virtual circular buffer, each of the data transfer segments between the host device and the storage media through the allocated physical buffers.

Buffering of data transfers for direct access block devices

Described embodiments provide a media controller that determines the size of a cache of data being transferred between a host device and one or more sectors of a storage device. The one or more sectors are segmented into a plurality of chunks, and each chunk corresponds to at least one sector. The contents of the cache are managed in a cache hash table. At startup of the media controller, a buffer layer module of the media controller initializes the cache in a buffer of the media controller. During operation of the media controller, the buffer layer module determines a number of chunks allocated to the cache. Based on the number of chunks allocated to the cache, the buffer layer module updates the size of the of the cache hash table.

Dynamic storage of cache data for solid state disks

Described embodiments provide logical-to-physical address translation for data stored on a storage device having sectors organized into blocks and superblocks. A flash translation layer maps a physical address in the storage device to a logical sector address. The logical sector address corresponds to mapping data that includes i) a page index, ii) a block index, and iii) a superblock number. The mapping data is stored in at least one summary page corresponding to the superblock containing the physical address. A block index and a page index of a next empty page in the superblock are stored in a page global directory corresponding to the superblock. A block index and a page index of the at least one summary page and the at least one active block table for each superblock are stored in at least one active block table of the storage device.

Logical-to-physical address translation for solid state disks

When parity checking in a disk array such as a RAID-6 system determines data and parity information is unsynchronized, additional calculations are performed to determine whether the error may be attributed to faulty data on a disk drive or to a more systemic problem such as a faulty controller. In particular, for each particular error detected, the parity generating information is analyzed to determine if each error involves a common disk index. If so, the data can be corrected on that disk; if not other corrective procedures are implemented.

Enhanced error identification with disk array parity checking

Described embodiments provide skip operations for transferring data to or from a plurality of non-contiguous sectors of a solid-state memory. A host layer module sends data to, and receives commands from, a communication link. Received commands are one of read requests or write requests, with commands including i) a starting sector address, ii) a skip mask indicating the span of all sector addresses in the request and the sectors to be transferred, iii) a total number of sectors to be transferred; and, for write requests, iv) the data to be written to the sectors. A buffer stores data for transfer to or from the solid-state memory. A buffer layer module i) manages the buffer, ii) segments the span of the request into a plurality of chunks, and iii) determines, based on the skip mask, a number of chunks to be transferred to or from the solid-state memory.

Skip operations for solid state disks

In a disk array environment such as a Redundant Array of Independent Disks-6 (RAID-6) environment, the overall performance overhead associated with exposed mode operations such as resynchronization, rebuild and exposed mode read operations is reduced through increased parallelism. By selecting only subsets of the possible disks required to solve a parity stripe equation for a particular parity stripe, accesses to one or more disks in a disk array may be omitted, thus freeing the omitted disks to perform other disk accesses. In addition, disk accesses associated with different parity stripes may be overlapped such that the retrieval of data necessary for restoring data for one parity stripe is performed concurrently with the storage of restored data for another parity stripe.

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Rochester, MN, United States of America

Carl E Forhan