Emc IP Holding Company LLC

Dell Products Inc.

Vamsi K Vankamamidi

Philippe Armangau

Geng Han

Shuyu Lee

Ajay Karri

Ashok Tamilarasan

Jian Gao

Vladimir Shveidel

Amitai Alkalay

Sorin Faibish

Xinlei Xu

Istvan Gonczi

Daniel E Cummins

Steven A Morley

Socheavy D Heng

Bruce E Caram

Ronen Gazit

Oran Asher Baruch

Philip N Shilane

Ivan Bassov

Yubing Wang

Ivan Basov

Shaul Dar

Maher Kachmar

Vikram A Prabhakar

Hongpo Gao

Yousheng Liu

Michael P Wahl

Maor Rahamim

Alexei Karaban

Christopher A Seibel

Oran Baruch

Anton Kucherov

Lior Kamran

Uri Shabi

Christopher Alan Seibel

Vasudevan Subramanian

Nimrod Shani

Alexander Shknevsky

Pavan Kumar Vutukuri

Mayank Ajmera

William C Davenport

Shaoqin Gong

Chun Ma

David W Harvey

Liam Xiongcheng Li

Ramakanth Kanagovi

Xiaobo Zhang

Svetlana Kronrod

Dixitkumar Vishnubhai Patel

Rongrong Shang

Guhesh Swaminathan

Samuel L Mullis, Ii

Sihang Xia

John F Gillono

Shari Vietry

Kamakshi Viswanadha

Jeffrey L Grummon

David Bernard

Charles Ma

Vikram Prabhakar

Andrew T Feld

James H Shimer

Ryan Gadsby

Swati Smita Sitha

James McCoy

Jibing Dong

Owen Martin

Jianbin Kang

Thomas Earl Linnell

Himabindu Tummala

Jamin Jianbin Kang

Richard P Ruef

Rohit K Chawla

Xiongcheng Li

Ree Sun

Thomas N Dibb

Kurt William Everson

Ronald D Proulx

Vasu Subramanian

Ming Wang

Steve Morley

Michael Litvak

Jason E Raff

Ami Sabo

Ping Ge

Jigang Wang

Andrew P Kubicki

Bijayalaxmi Nanda

Christopher Jones

Paras Pandya

Christopher J Jones

David Ben-David

Qiu Zhong

Alex Wang

Amital Alkalay

Edward Zhao

Zhuoqun Yuan

Vibhash M Desai

Techniques for limiting or reducing storage accessibility 'hiccups' in active-active clustered systems that perform large writes. The techniques can include executing, by a surviving, failover, or rebooted node of an active-active clustered system, a specialized recovery protocol that includes treating each large write request from a host computer as a plurality of small write requests while execution of the specialized recovery protocol is in progress, draining all dedicated sub-ubers for a primary and secondary node of the active-active clustered system, and, having completed execution of the specialized recovery protocol, resuming normal treatment of large write requests from the host computer. In this way, the need and complexity of managing large writes and maintaining their corresponding sub-uber information during recovery from a forced reboot, crash, or disaster involving the primary or secondary node can be avoided, and storage accessibility hiccups due to performing the large writes can be limited or reduced.

Low hiccup time fail-back in active-active dual-node storage systems with large writes

Techniques can include: receiving, at a first node, a read I/O directed to a logical address; determining that the first node does not own the logical address; sending over an interconnect a redirect request from the first node to a second node that owns the first logical address; and the second node performing processing including: determining, in accordance with one or more criteria, whether the interconnect is overloaded; responsive to determining that the interconnect is not overloaded, sending a redirect reply over the interconnect to the first node where the redirect reply includes first content stored at the first logical address; and responsive to determining that the interconnect is overloaded, sending the redirect reply over the interconnect to the first node where the redirect reply includes physical location information identifying a first physical storage location or address on non-volatile storage of the first content of the first logical address.

I/O processing techniques in a multi-node system

A method, computer program product, and computing system for receiving a metadata page for storage within a log-structured metadata store. An entry may be generated within a translation table page of a translation table within the log-structured metadata store, wherein each entry of a plurality of entries within the translation table page is associated with a separate metadata page. One or more metadata page deltas for the metadata page may be recorded in the log-structured metadata store. The one or more metadata page deltas for the metadata page may be flushed to a persistent memory storage. In response to flushing the one or more metadata page deltas for the metadata page, the entry within the translation table page that is associated with the metadata page may be updated without accessing any other entry within the translation table page associated with other metadata pages.

System and method for managing metadata access in a log-structured system

In at least one embodiment, processing can include: receiving, from a client, a request to access a metadata (MD) page, wherein the request specifies a lock type denoting a particular level of access to the MD page that is being requested by the request; and responsive to receiving the request, performing first processing including: locking the MD page and a corresponding translation table entry Efor the MD page in accordance with the lock type denoting a particular level of access being requested, wherein Emaps a logical address LAof the MD page to a physical storage or location PAon non-volatile storage where the MD page is stored; and subsequent to said locking, returning a response including the MD page to the client.

Techniques for destaging translation table updates and accessing translation table entries in a log-structured system

In at least one embodiment, processing can include: recording write operations as entries in a log; flushing the entries from the log, said flushing including persistently storing, on non-volatile storage, content written by the write operations; responsive to determining a system has a current workload below a specified workload threshold, performing first processing including: determining a first minimum number of free blocks of the non-volatile storage based on: i) an average number of free blocks expected to be consumed in connection with flushing the log in each time interval, ii) a constant, and iii) a second minimum number of blocks denoting an upper bound of a number of blocks of the non-volatile storage consumed by flushing the log in each time interval; and responsive to determining that a current number of free blocks is less than the first minimum number, performing garbage collection processing on the non-volatile storage.

Data storage management techniques

A technique is directed to managing wear leveling between storage devices. The technique includes obtaining a wear level metric of a candidate storage extent that includes storage from multiple storage devices. The technique further includes performing an assessment operation that provides an indication that the candidate storage extent satisfies an access criterion. The access criterion is based on the wear level metric. The technique further includes, in response to the assessment operation providing the indication that the candidate storage extent satisfies the access criterion, performing a set of access operations that accesses the candidate storage extent.

Managing storage extents using wear levels

A technique of managing writes in a data storage system includes receiving I/O requests specifying data to be written, storing a set of the data to be written in an extent of a data log, and preventing data reduction from being performed on the set of data in the extent for at least a specified time interval, said time interval enabling portions of the set of data to be overwritten with new data and rendering data reduction of such portions unnecessary.

Avoiding data reduction debt for quickly overwritten data

A method, computer program product, and computing system for defining a plurality of IO processing queues within a storage system coupled to a storage platform, wherein the plurality of IO processing queues have differing priority levels; receiving one or more IO requests on the storage system coupled to the storage platform; assigning the one or more IO requests to one or more of the plurality of IO processing queues based, at least in part, upon a priority level of the one or more IO requests; and servicing the plurality of IO processing queues in a distributed fashion.

System and method using IOPS to service priority queues in a distributed manner

Techniques providing data path strategies for improving storage performance at DR sites. The techniques include receiving, in an asynchronous replication process, a large replication data transfer including data changes of a production volume since the last synchronization to a replica volume, partitioning the replication data into multiple small write requests, tagging each small write request as a write request to the replica volume, and performing early evicting, from cache memory, all cache pages used to cache host data specified in the small write requests; deep compression of contiguous host data specified in the small write requests; stream separation on the small write requests, each small write request being tagged as corresponding to a specific production site; and/or flushing host data having the same retention period to a specific region of physical storage space for the replica volume, each small write request being tagged with hint information indicating the retention period.

Data path strategies for replica volumes

Techniques manage data within storage equipment having a Flexible Data Placement (FDP) drive. The techniques involve configuring the storage equipment to support storing data in reclaim units of the FDP drive according to an initial group of reclaim unit handles. The techniques further involve detecting that a number of currently available reclaim units of the FDP drive has fallen below a first predefined threshold. The techniques further involve, in response to detecting that the number of currently available reclaim units of the FDP drive has fallen below the first predefined threshold, reconfiguring the storage equipment to support storing data in reclaim units of the FDP drive according to a smaller group of reclaim unit handles. The smaller group of reclaim unit handles has fewer reclaim unit handles than the initial group of reclaim unit handles.

Managing reclaim unit handles to control access to a flexible data placement drive

A technique for managing a mapping structure in a data storage system includes identifying levels in the mapping structure of pages to be removed and estimating the workload required for removing the pages based at least in part on the identified levels. The technique further includes initiating processing of the pages based at least in part on the estimated workload.

Processing pages marked for deletion

A method, computer program product, and computing system for generating a plurality of page buffers from a log memory system of the storage system using a persistent memory organization policy. A plurality of physical layer blocks (PLBs) are generated from the log memory system using the persistent memory organization policy. A set of page buffers are allocated from the plurality of page buffers to a first mapping page of a plurality of mapping pages. A PLB is allocated from the plurality of PLBs to a second mapping page of the plurality of mapping pages. One or more IO requests are processed using one or more of the first mapping page and the second mapping page.

System and method for flushing data using mapping page ownership

When a host I/O request is received, logging each transaction that is to be performed to process the host I/O request includes selecting from between a first persistent storage and a second persistent storage to identify the location to which the transaction is to be logged, and then logging the transaction to the selected location. The selection may be made based on a log policy indicating percentages of transactions to be logged to each of the first persistent storage and the second persistent storage. The percentages may be calculated periodically based on a dynamically measured performance characteristic of the first data storage, such as latency. All transactions for host I/O requests below a threshold minimum size, and/or all transactions for host I/O requests received while the current system throughput is below a minimum system throughput, may be logged to the first persistent storage.

Persistently storing a transaction log in a data storage system based on a log policy

Improved techniques are directed to managing a cache in an electronic environment in which a first processing core is configured to utilize a first set of queues to reclaim the pages of the cache and a second processing core is configured to utilize a second set of queues to reclaim the pages of the cache. The techniques include adding, to a queue in the first set of queues, an entry identifying access information of a page of the cache. The techniques further include accessing the page by a second processing core. The techniques further include, while the entry is in the first set of queues, updating the access information by the second processing core to indicate accessing the page by the second processing core.

Managing caches using access information of cache pages

A technique for managing transient snapshots identifies an instruction to create a transient snapshot with an indicator and attempts to delay, based on the indicator, flushing of the instruction from cache to a mapping subsystem at least until the cache receives an instruction to delete the transient snapshot.

Managing transient snapshots for reduced metadata writes

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Hopkinton, MA, United States of America

Vamsi K Vankamamidi