International Business Machines Corporation

Avago Technologies International Sales Pte. Limited

Avago Technologies General IP (singapore) Pte. Ltd.

Gowrisankar Radhakrishnan

Daniel Frank Moertl

Adrian Cuenin Gerhard

Rick A Weckwerth

Brian Eric Bakke

Robert Edward Galbraith

Joseph R Edwards

Horia Cristian Simionescu

Timothy E Hoglund

Sridhar Rao Veerla

Panthini Pandit

Donald J Ziebarth

Michael Joseph Carnevale

Brian L Bowles

Murali N Iyer

Mark J Moran

Robert E Galbraith, Ii

Shawn P Authement

Christopher M Dennett

Daniel F Moerti

A system and method for efficient cache flushing are provided. The disclosed method includes maintaining a data structure in connection with a plurality of blocks used for data caching, the data structure including a row lock wait list section. The method further includes receiving an Input/Output (I/O) request, performing a hash search for the I/O request against the data structure, and based on the results of the hash search, locking at least one row in a data cache thereby preventing read and write operations from being performed on the at least one row until the at least one row is unlocked.

Method and system for hardware accelerated row lock for a write back volume

A system and method for managing bad blocks in a hardware accelerated caching solution are provided. The disclosed method includes receiving an Input/Output (I/O) request, performing a hash search for the I/O request against a hash slot data structure, and based on the results of the hash search, either performing the I/O request with a data block identified in the I/O request or diverting the I/O request to a new data block not identified in the I/O request. The diversion may also include diverting the I/O request from hardware to firmware of a memory controller.

Method and system for handling bad blocks in a hardware accelerated caching solution

Disclosed are embodiments for supporting dynamic tier remapping of data stored in a hybrid storage system. One embodiment includes a storage controller and firmware, where the firmware maintains a plurality of mapping elements, where each mapping element includes a plurality of group identifiers, where each group identifier is configured to indicate a mapping of a logical block addresses, and where the storage controller performs: receiving a read command including a logical block address; parsing the logical block address to determine a mapping element and a group identifier; determining, for a particular mapping element of the plurality of elements, whether the particular mapping element is locked, wherein the particular mapping element corresponds to the mapping element of the logical block address; and dependent upon the particular mapping element, queuing the read command for firmware processing or remapping the logical block address.

Dynamic tier remapping of data stored in a hybrid storage system

A system and method for performing a copyback operation are provided. The disclosed method includes initiating a copyback process to move data from an online data storage drive to a spare data storage drive by setting an indicator in hardware to divert all write completions on the online data storage drive. The method further includes, while the indicator in hardware is set to divert the write completions, incrementing on a per-strip basis a copy of data from the online data storage drive to the spare data storage drive. The method further includes only after all data from the online data storage drive has been copied to the spare data storage drive, changing the setting of the indicator in hardware so that write requests received for the online data storage drive during the copyback process are re-issued on to the spare data storage drive.

Method and system for hardware accelerated copyback

A system and method for efficient cache flushing are provided. The disclosed method includes allocating one or more Internal Scatter Gather Lists (ISGLs) for the cache flush, populating the one or more ISGLs with Cache Segment Identifiers (CSIDs) and corresponding Buffer Segment Identifiers (BSIDs) of each strip that is identified as dirty, of a skip-type Internal Scatter Gather Element (ISGE), or of a missing arm-type ISGE. The disclosed method further includes allocating a flush Local Message Identifier (LMID) as a message to be used in connection with processing the cache flush, populating the flush LMID with an identifier of the one or more ISGLs, and transferring the flush LMID to a cache manager module to enable the cache manager module to execute the cache flush based on information contained in the flush LMID.

Method and system for hardware accelerated cache flush

A system and method for efficient cache buffering are provided. The disclosed method determining that a read-ahead operation is to be performed in response to receiving a host Input/Output (I/O) command. In response to determining that the read-ahead operation is to be performed, allocating a new Local Message Identifier (LMID) for the read-ahead operation. The method further includes sending a buffer allocation request to a buffer manager module, the buffer allocation request containing parameters associated with the read-ahead operation and then causing the buffer manager module to allocate at least one Internal Scatter Gather List (ISGL) and Buffer Section Identifier (BSID) in accordance with the parameters contained in the buffer allocation request. The method further includes enabling the cache manager module to perform a hash search using a row or strip number and identification information available in the new LMID.

Method and system for hardware accelerated read-ahead caching

A system and method for efficient cache buffering are provided. The disclosed method includes receiving an Input/Output (I/O) command from a host system at a storage controller, parsing the I/O command at the storage controller with a host I/O manager to extract command instructions therefrom. The host I/O manager is able to generate at least one local message that includes the command instructions extracted from the I/O command and transmit the at least one local message to a cache manager. The cache manager is enabled to work in local memory to execute the command instructions contained in the at least one message. The cache manager is also configured to chain multiple buffer segments together on-demand to support multiple stripe sizes that are specific to the I/O command received from the host system.

Method and system for efficient cache buffering supporting variable stripe sizes to enable hardware acceleration

A system and method for efficient cache buffering are provided. The disclosed method includes receiving a host command from a host, extracting command information from the host command, determining an Input/Output (I/O) action to be taken in connection with the host command, determining that the I/O action spans more than one strip, and based on the I/O action spanning more than one strip, allocating a cache frame anchor for a row on-demand along with a cache frame anchor for a strip to accommodate the I/O action.

Method and system for efficient cache buffering in a system having parity arms to enable hardware acceleration

A method and controller for implementing storage adapter enhanced write cache management, and a design structure on which the subject controller circuit resides are provided. The controller includes a hardware write cache engine implementing hardware acceleration for storage write cache management. The hardware write cache engine monitors cache levels used for managing cache destage rates and thresholds for destages from storage write cache substantially without using firmware for greatly enhancing performance.

Implementing hardware accelerator for storage write cache management for managing cache destage rates and thresholds for storage write cache

A system and method for efficient cache buffering are provided. The disclosed method includes receiving a host command from a host, extracting command information from the host command, determining an Input/Output (I/O) action to be taken in connection with the host command, identifying a particular memory module from among a plurality of memory modules to execute the I/O action, generating an accelerated I/O message for transmission to the particular memory module, the accelerated I/O message comprising at least one Internal Scatter Gather List (ISGL) having a plurality of Scatter Gather Extents (SGEs) that enable the particular memory module to execute the I/O action solely based on the at least one ISGL, and transmitting the accelerated I/O message to the particular memory module.

Memory controller utilizing scatter gather list techniques

A method and controller for implementing storage adapter enhanced write cache management, and a design structure on which the subject controller circuit resides are provided. The controller includes a hardware write cache engine implementing hardware acceleration for storage write cache management. The hardware write cache engine performs destage operations from storage write cache with minimal firmware involvement to enhance performance.

Implementing hardware accelerator for storage write cache management for destage operations from storage write cache

A method and controller for implementing storage adapter enhanced write cache management, and a design structure on which the subject controller circuit resides are provided. The controller includes a hardware write cache engine implementing hardware acceleration for storage write cache management. The hardware write cache engine performs data age identification in storage write cache substantially without firmware involvement for greatly enhancing performance.

Implementing hardware accelerator for storage write cache management for identification of data age in storage write cache

A method and controller for implementing storage adapter enhanced write cache management, and a design structure on which the subject controller circuit resides are provided. The controller includes a hardware write cache engine implementing hardware acceleration for storage write cache management. The hardware write cache engine manages cache line updates for purges from storage write cache with no firmware involvement for greatly enhancing performance.

Implementing hardware accelerator for storage write cache management for managing cache line updates for purges from storage write cache

A method and controller for implementing storage adapter enhanced write cache management, and a design structure on which the subject controller circuit resides are provided. The controller includes a hardware write cache engine implementing hardware acceleration for storage write cache management. The hardware write cache engine performs cache line updates for writes, reads, and destages from storage write cache substantially without firmware involvement for greatly enhancing performance.

Implementing hardware accelerator for storage write cache management for managing cache line updates for writes, reads, and destages in storage write cache

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Colorado Springs, CO, United States of America

Gowrisankar Radhakrishnan