公开(公告)号：US20210109891A1

公开(公告)日：2021-04-15

申请号：US16653418

申请日：2019-10-15

Applicant: EMC IP Holding Company LLC

Inventor： Deepak Vokaliga

IPC: G06F16/11 ,  G06F11/14

Abstract: Multi-policy interleaved snapshot lineage is described herein. A method can include assigning a virtual storage volume at a remote storage system to a local storage device according to first and second data retention policies for first and second storage groups, respectively, that comprise the local storage device; obtaining a first data snapshot of the local storage device at a first time according to the first data retention policy; in response to the obtaining the first data snapshot, transferring a first incremental representation of the first data snapshot to the virtual storage volume; obtaining a second data snapshot of the local storage device at a second time according to the second data retention policy; and in response to the obtaining the second data snapshot, transferring a second incremental representation of the second data snapshot to the virtual storage volume.

公开(公告)号：US10936451B2

公开(公告)日：2021-03-02

申请号：US16168910

申请日：2018-10-24

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Toufic Tannous ,  Bhaskar Bora ,  Deepak Vokaliga

IPC: G06F3/06 ,  G06F12/126 ,  G06F12/0868 ,  G06F12/084 ,  G06F12/02 ,  G06F11/20

Abstract: In a data storage system in which a first storage array and a second storage array maintain first and second replicas of a production volume, the first storage array is responsive to a write command from a host to send a notification to the second storage array indicating that the replicated production volume will be updated. The notification has information that enables the second storage array to implement pre-processing steps to prepare for subsequent receipt of data associated with the write command. Both storage arrays implement the pre-processing steps at least partly concurrently. When the data associated with the write command is subsequently received, the first storage array writes the data to cache and then sends a copy of the data to the second storage array, i.e. in series. The second storage array then writes the data to cache. Elapsed time between receipt of the write command and returning an acknowledgment to the host may be improved by concurrent pre-processing.

公开(公告)号：US10911540B1

公开(公告)日：2021-02-02

申请号：US16814492

申请日：2020-03-10

Applicant: EMC IP Holding Company LLC

Inventor： Shanmuga Anand Gunasekaran ,  Deepak Vokaliga ,  Michael Anthony ,  Mark Aldred ,  Anurag Bhatnagar

IPC: G06F11/14 ,  G06F16/11 ,  G06F16/22 ,  G06F12/16 ,  H04L29/08 ,  G06F9/54 ,  H04L29/06

Abstract: An apparatus comprises a processing device configured to identify a snapshot lineage comprising snapshots of a given set of storage volumes, the snapshot lineage comprising (i) a local snapshot lineage stored on a storage system and (ii) a cloud snapshot lineage stored on cloud storage of a cloud external to the storage system. The processing device is also configured to select a snapshot to recover from the cloud snapshot lineage to the storage system, to create a set of new storage volumes on the storage system, to generate a recovery map linking each of a set of cloud storage volumes on the cloud storage that comprises data of the selected snapshot to at least one of the new storage volumes, and to recover the selected snapshot from the cloud snapshot lineage by copying data from the set of cloud storage volumes to corresponding linked ones of the new storage volumes.

公开(公告)号：US09933947B1

公开(公告)日：2018-04-03

申请号：US14984376

申请日：2015-12-30

Applicant: EMC IP Holding Company LLC

Inventor： Deepak Vokaliga ,  Benjamin Yoder ,  Vadim Longinov ,  George Quill ,  Benoit Joseph Merlet

IPC: G06F3/06 ,  G06F12/08 ,  G06F12/0802

CPC classification number: G06F3/061 ,  G06F3/0617 ,  G06F3/0638 ,  G06F3/065 ,  G06F3/0671 ,  G06F3/0683 ,  G06F11/00 ,  G06F12/0802 ,  G06F12/0895 ,  G06F2212/1016 ,  G06F2212/285 ,  G06F2212/60

Abstract: Techniques are described for processing multi-page write operations to maintain write level consistency. A multi-page write spanning multiple cache pages is directed to a target device and received on a first data storage system where writes to the target device are synchronously replicated to a second data storage system. On the first data storage system, each of the multiple cache pages may be synchronously replicated to the second data storage system. A lock on each of the cache pages is not released until an acknowledgement is received regarding successful replication of the cache page. On the second data storage system, requests to replicate the multiple cache pages containing write data of the multi-page write are received and processed using locks of corresponding cache pages on the second data storage system. Such techniques also handle concurrent reads and/or writes. Deadlock detection and resolution processing may be performed for concurrent writes.

公开(公告)号：US11893260B2

公开(公告)日：2024-02-06

申请号：US17238103

申请日：2021-04-22

Applicant: EMC IP Holding Company LLC

Inventor： Bhaskar Bora ,  Mark J. Halstead ,  Deepak Vokaliga ,  Benjamin Yoder ,  William R. Stronge

IPC: G06F3/06 ,  G06F11/14

CPC classification number: G06F3/065 ,  G06F3/067 ,  G06F3/0619 ,  G06F3/0659 ,  G06F3/0683 ,  G06F11/1435 ,  G06F2201/84

Abstract: Snapshots may be used to implement remote replication, for example, asynchronously, between a first storage system, A1, and a second storage system, A2. A1 may take a first snapshot, SS21, of a logical storage unit, R1. After the snapshot SS21 it taken, any dependent write operations associated with SS21 may be reconciled, and differences between SS21 and the last snapshot for R1, SS11, may be determined and recorded as a difference set. One or more replication instructions for R1 that include the write operations (or data and metadata corresponding thereto) of the difference set may be sent from A1 to A2. A2 may apply the differences to R2, and then take (activate) a snapshot of R2, SS22, which is a replica of SS21. After A2 activates SS22, A2 may send an acknowledgement to A1 indicating that SS22 has been activated, and A2 may take a next snapshot of R1.

公开(公告)号：US20220342908A1

公开(公告)日：2022-10-27

申请号：US17237127

申请日：2021-04-22

Applicant: EMC IP Holding Company LLC

Inventor： Bhaskar Bora ,  Deepak Vokaliga ,  Mark J. Halstead ,  Jeffrey Wilson ,  William R. Stronge ,  Ian Adams

IPC: G06F16/27

Abstract: Snapshots from a first LSU (R1) on a first storage system (A1) may be replicated to a second replica LSU (R2) on a second storage system (A2), for example, concurrently to remotely replicating (e.g., synchronously) write operations for R1 to R2. A process, P, on A1 executing the replication of the snapshots from R1 to R2 may be a separate process than the one or more processes on A1 executing remote replication of write operations for R1 to R2. During a consistency window on A1, outstanding write operations for R1 at the time the consistency window opened may be logged, and a pair of snapshots, SS11 and SS12 may be activated on R1 and R2, respectively. After the consistency window has closed, the SS12 snapshot metadata and snapshot data may be updated based on the outstanding write operations.

公开(公告)号：US11468091B2

公开(公告)日：2022-10-11

申请号：US17023525

申请日：2020-09-17

Applicant: EMC IP Holding Company LLC

Inventor： Bhaskar Bora ,  Mark J. Halstead ,  Michael E. Specht ,  Benjamin Yoder ,  Deepak Vokaliga

IPC: G06F16/27 ,  G06F12/0802

Abstract: Maintaining consistency for asynchronous replication of LUNs of a local storage system to corresponding LUNs of a remote storage system includes copying application data written to LUNs to cache slots, copying metadata of LUNs to cache slots, associating a first sequence number to all metadata modifications and all application data writes that are begun after a first time and before a second time, associating a second sequence number, different from the first sequence number, to all metadata modifications and all application data writes that are begun after the second time, and, after completion of all metadata modifications and all application data writes associated with the first sequence number, initiating transfer to the remote storage system of all metadata modifications and all application data writes associated with the first sequence number. Each cache slot may include a field that indicates a corresponding sequence number.

公开(公告)号：US11327844B1

公开(公告)日：2022-05-10

申请号：US17084691

申请日：2020-10-30

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Francisco Aquino ,  Kenneth Byrne ,  Warren Fleury ,  Thiago Santos ,  Deepak Vokaliga

IPC: G06F12/00 ,  G06F11/14 ,  G06F3/06

Abstract: A storage array creates snapshots of each of a plurality of devices of a storage group associated with a production device on which active application data is logically stored. Metadata that indicates associations between the snapshots and the devices is stored on cloud storage with the snapshots as a snapset object. A program running on a management station used the snapset metadata to automatically create new devices on which to recover the snapshots on a selected storage array and uses the snapset metadata to cause the snapshots to be automatically written from the cloud storage system to the new devices on the selected storage array.

公开(公告)号：US20220138047A1

公开(公告)日：2022-05-05

申请号：US17084691

申请日：2020-10-30

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Francisco Aquino ,  Kenneth Byrne ,  Warren Fleury ,  Thiago Santos ,  Deepak Vokaliga

IPC: G06F11/14 ,  G06F3/06

Abstract: A storage array creates snapshots of each of a plurality of devices of a storage group associated with a production device on which active application data is logically stored. Metadata that indicates associations between the snapshots and the devices is stored on cloud storage with the snapshots as a snapset object. A program running on a management station used the snapset metadata to automatically create new devices on which to recover the snapshots on a selected storage array and uses the snapset metadata to cause the snapshots to be automatically written from the cloud storage system to the new devices on the selected storage array.

公开(公告)号：US11315028B2

公开(公告)日：2022-04-26

申请号：US17010945

申请日：2020-09-03

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Deepak Vokaliga ,  Rong Yu

IPC: G06F12/00 ,  G06F13/00 ,  G06N5/04 ,  G06F3/06

Abstract: A method of increasing the accuracy of predicting future IO operations on a storage system includes creating a snapshot of a production volume, linking the snapshot to a thin device, mounting the thin device in a cloud tethering subsystem, and tagging the thin device to identify the thin device as being used by the cloud tethering subsystem. When data read operations are issued by the cloud tethering subsystem on the tagged thin device, the data read operations are executed by a front-end adapter of the storage system to forward data associated with the data read operations to a cloud repository. The cache manager, however, does not use information about data read operations on tagged thin devices in connection with predicting future IO operations on the cache, so that movement of snapshots to the cloud repository do not skew the algorithms being used by the cache manager to perform cache management.