公开(公告)号：US10824513B1

公开(公告)日：2020-11-03

申请号：US16398879

申请日：2019-04-30

Applicant: EMC IP Holding Company LLC

Inventor： Sandeep Chandrashekhara ,  David T. Tsang ,  Michael Ferrari ,  Jeffrey Wilson ,  Mark J. Halstead

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

Abstract: An apparatus in one embodiment comprises at least one processing device having a processor coupled to a memory. The processing device is configured to maintain, for logical storage volumes of a storage system, device sequence numbers for snapshot and extent copy operations. The processing device is also configured to maintain, for at least one track of the logical storage volumes, a track sequence number representing the state of the track with respect to the snapshot and extent copy operations. The processing device is further configured to receive input/output operations directed to the logical storage volumes from host devices coupled to the storage system while at least one snapshot or extent copy operation for the logical storage volumes is in progress, and to utilize the track sequence numbers and the device sequence numbers to determine processing of the received input/output operations while the snapshot or extent copy operations are in progress.

公开(公告)号：US11874795B2

公开(公告)日：2024-01-16

申请号：US16885495

申请日：2020-05-28

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Jeffrey Wilson ,  Michael Ferrari ,  Sandeep Chandrashekhara

IPC: G06F16/11 ,  G06F16/188 ,  G06F16/901 ,  G06F16/182

CPC classification number: G06F16/128 ,  G06F16/184 ,  G06F16/188 ,  G06F16/1827 ,  G06F16/9017

Abstract: A first direct index lookup table represents the current state of a storage object using entries with references corresponding to tracks of the storage object. A second direct index lookup table represents a first targetless snapshot of the storage object. A virtual replication data pointer table maps the entries of both the first direct index lookup table and the entries of the second direct index lookup table to backend storage via a system replication data pointer table. Updates to the storage object are represented using new entries in the first direct index lookup table and the system replication data pointer table. Movement of a track that is represented in multiple targetless snapshots that are represented by multiple direct index lookup tables is represented by updating the corresponding virtual replication data pointer table and system replication data pointer table rather than updating each of the direct index lookup tables.

公开(公告)号：US11449237B2

公开(公告)日：2022-09-20

申请号：US16885542

申请日：2020-05-28

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Michael Ferrari ,  Jeffrey Wilson ,  Sandeep Chandrashekhara

IPC: G06F3/06 ,  G06F11/14

Abstract: Storage objects and targetless snaps of the storage objects are represented using a system replication data pointer table (SRT), direct index lookup (DIL) tables, and virtual replication data pointer tables (VRTs). The SRT is a system level track-based data structure that stores metadata indicative of the actual (physical layer) allocations for all targetless snapshots in a storage array. The size of the SRT in terms of total entries corresponds to the overall storage capacity of the managed drives of the storage array. Each utilized entry of the SRT includes backend metadata with a pointer to a managed drive and metadata that identifies the associated storage object and track via the VRTs and DIL tables. SRT metadata is created and discarded as backend allocations are utilized and freed so the SRT is a dynamic data structure that can efficiently adjust its size and corresponding memory requirements.

公开(公告)号：US11347641B2

公开(公告)日：2022-05-31

申请号：US16671372

申请日：2019-11-01

Applicant: EMC IP Holding Company LLC

Inventor： Jeffrey Wilson ,  Michael Ferrari ,  Shruti Gupta ,  George F. Lettery

IPC: G06F12/02

Abstract: Snapshot metadata may include a plurality of pages of nodes, including active nodes and free nodes. It may be determined whether a snapshot metadata object is eligible for de-allocation, for example, of one or more of the pages of its snapshot metadata nodes. This determination may be based on a number of free nodes in the snapshot metadata object, for example, in relation to the quantity of nodes that are included in a snapshot metadata page. This determination may be made based on previous usage of the nodes allocated to the snapshot metadata object, for example, the number of active nodes relative to a total size of the snapshot metadata object. For example, a maximum extent of active nodes during one or more periods may be compared to a current extent of active nodes to determine whether the snapshot metadata object is eligible.

公开(公告)号：US20210157678A1

公开(公告)日：2021-05-27

申请号：US16692742

申请日：2019-11-22

Applicant: EMC IP Holding Company LLC

Inventor： Sandeep Chandrashekhara ,  Michael Ferrari ,  Jeffrey Wilson ,  Mark J. Halstead ,  Art Longden

IPC: G06F11/14 ,  G06F12/1009

Abstract: A no-copy clone of a logical storage unit is created. A define process is initiated for defining a target logical storage unit as the clone before activation of the target logical storage unit. By initiating the define process before activating the logical storage unit, there is a greater likelihood that, when a write operation is received for a data portion on the source logical storage unit or target logical storage unit after activation of the target LSU, the data portion will already be defined and not need to be defined when performing the write operation. When a write operation is received at the source logical storage unit, if the target logical storage unit is not active yet, the data of the write operation may be written to an allocated physical location for the data portion shared between the source and target logical storage units without updating any clone metadata.

公开(公告)号：US20210133115A1

公开(公告)日：2021-05-06

申请号：US16672228

申请日：2019-11-01

Applicant: EMC IP Holding Company LLC

Inventor： Jeffrey Wilson ,  Michael Ferrari ,  Shruti Gupta ,  George F. Lettery

IPC: G06F12/122

Abstract: Memory may be used more efficiently for snapshot metadata by reducing a size of a snapshot metadata object, for example, by removing free nodes from the snapshot metadata object. Removing free nodes may include consolidating free nodes into a single page of a snapshot metadata object and de-allocating the page from the memory allocated for the data structure. Consolidation of free nodes may be achieved by identifying active nodes in the single page, and swapping these active nodes with free nodes from other pages until the single page includes only free nodes. The nodes of the single page that were already free and the active nodes that were swapped with free nodes from another page may be designated for de-allocation. This designating may result in all nodes of the single page being designated for de-allocation, after which the single page of nodes may be de-allocated.

公开(公告)号：US12008018B2

公开(公告)日：2024-06-11

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 ,  G06F11/14

CPC classification number: G06F16/275 ,  G06F16/27 ,  G06F11/1446 ,  G06F2201/84

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：US11755230B2

公开(公告)日：2023-09-12

申请号：US17237171

申请日：2021-04-22

Applicant: EMC IP Holding Company LLC

Inventor： Ian Adams ,  Bhaskar Bora ,  Jeffrey Wilson

IPC: G06F3/06

CPC classification number: G06F3/065 ,  G06F3/067 ,  G06F3/0619 ,  G06F3/0659

Abstract: Snapshots may be remotely replicated asynchronously from a first LSU (R1) on a first storage system (A) to a second replica LSU (R2) on a second storage system (A2). The storage system A1 may open a consistency window to suspend initiating processing of new write operations received on A1. While the consistency window is open, A1 may: take a first snapshot, SS11, of R1; record, in association with the first replication cycle, an indication to replicate SS11 on A2; and initiate a next replication cycle to record write operations of the next new write requests to be received from hosts. After initiating a next replication cycle, A1 may close the consistency and transmit the first replication cycle to A2. A2 may apply the write operations of the first replication cycle to R2, and then take a second snapshot SS12 of R2, which should be a replica of SS11.

公开(公告)号：US11656769B2

公开(公告)日：2023-05-23

申请号：US16923376

申请日：2020-07-08

Applicant: EMC IP Holding Company LLC

Inventor： Owen Martin ,  Jeffrey Wilson

IPC: G06F3/06 ,  G06F21/78

CPC classification number: G06F3/0623 ,  G06F3/067 ,  G06F3/0619 ,  G06F3/0631 ,  G06F3/0653 ,  G06F21/78

Abstract: Embodiments of the present disclosure relate to autonomous data protection. An input/output (I/O) stream can be received for a storage device. One or more anomalies corresponding to the I/O stream can be identified. At least one of the one or more anomalies can be offloaded anomalies to a remote storage based on a capacity of memory allocated to store at least one snapshot of the storage device that include at least one of the one or more anomalies.

公开(公告)号：US11513900B2

公开(公告)日：2022-11-29

申请号：US17237100

申请日：2021-04-22

Applicant: EMC IP Holding Company LLC

Inventor： Bhaskar Bora ,  Mark J. Halstead ,  Jeffrey Wilson

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

Abstract: Snapshots of a first logical storage unit (LSU) (R1) on a first storage system (A1) may be taken while replication is inactive between A1 and a second storage system (A2), such that these outstanding snapshots are not replicated to a second replica LSU (R2) on A2. Upon replication becoming active, the outstanding snapshots may be replicated to R2 without disrupting or impairing the remote replication of write operations between R1 and R2 as part of standard remote replication. A process on A1 executing the replication of the outstanding snapshots from R1 to R2 may be a separate process than one or more processes on A1 executing standard remote replication including the replication of write operations from R1 to R2. The process may be given low priority on A1 so as to not impair performance of other operations, including standard remote replication and replicating outstanding write operations on A1.