公开(公告)号：US20220342762A1

公开(公告)日：2022-10-27

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: 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.

公开(公告)号：US20210374095A1

公开(公告)日：2021-12-02

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 ,  G06F16/182 ,  G06F16/901

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：US11100008B2

公开(公告)日：2021-08-24

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：US10282107B1

公开(公告)日：2019-05-07

申请号：US14985769

申请日：2015-12-31

Applicant: EMC IP Holding Company LLC

Inventor： Owen Martin ,  Hui Wang ,  Jaeyoo Jung ,  James L. Davidson ,  Jeffrey Wilson

IPC: G06F3/06

Abstract: Described are techniques for controlling I/O response time. It is determined whether a first observed I/O response time for a storage group exceeds I/O performance specified by a service level objective. If so, first processing may be performed to decrease I/O performance for the storage group. The first processing may include: for each I/O directed to the storage group that is received within a first subsequent time period, determining a first response time denoting an amount of time taken to service each I/O prior to returning a response for each I/O; determining whether the first response time for each I/O is less than a response time delay threshold; and if the first response time for each I/O is less than the response time delay threshold, applying a response time delay to each I/O prior to returning a response for each I/O.

公开(公告)号：US11586527B2

公开(公告)日：2023-02-21

申请号：US17246600

申请日：2021-05-01

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Jeffrey Wilson ,  Mordechai Grutman

IPC: G06F9/44 ,  G06F11/36

Abstract: A model of an algorithm to be tested is created based on the steps that the algorithm uses to implement a particular function. The model is used by an algorithm verification process to control execution of the application under test. Stubs (small pieces of code) are inserted into the application under test which are used to control execution of the algorithm to determine the result of execution of the algorithm at various locations. The remote stubs enable the testing framework to control execution of the application, stop execution of the application, view data structures associated with the application, freeze system behavior, induce multi-layered dependent sequences, analyze logs, change system flow based on test requests, examine internal data structures as part of the tests, and verify that each method and the combined results of the methods are as expected, based on the original definition of the application algorithm.

公开(公告)号：US20220350727A1

公开(公告)日：2022-11-03

申请号：US17246600

申请日：2021-05-01

Applicant: EMC IP HOLDING COMPANY LLC

Inventor： Jeffrey Wilson ,  Mordechai Grutman

IPC: G06F11/36

Abstract: A model of an algorithm to be tested is created based on the steps that the algorithm uses to implement a particular function. The model is used by an algorithm verification process to control execution of the application under test. Stubs (small pieces of code) are inserted into the application under test which are used to control execution of the algorithm to determine the result of execution of the algorithm at various locations. The remote stubs enable the testing framework to control execution of the application, stop execution of the application, view data structures associated with the application, freeze system behavior, induce multi-layered dependent sequences, analyze logs, change system flow based on test requests, examine internal data structures as part of the tests, and verify that each method and the combined results of the methods are as expected, based on the original definition of the application algorithm.

公开(公告)号：US20220011950A1

公开(公告)日：2022-01-13

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

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：US20210373780A1

公开(公告)日：2021-12-02

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：US11188425B1

公开(公告)日：2021-11-30

申请号：US16885702

申请日：2020-05-28

Applicant: EMC IP Holding Company LLC

Inventor： Kevin M. Tobin ,  Andrew L. Chanler ,  Michael Ferrari ,  Jeffrey Wilson

IPC: G06F11/14 ,  G06F3/06

Abstract: Snapshots may be managed on a data storage system including logical storage unit including data portions. For a first logical storage unit, a first snapshot pointer structure may be provided including entries, each entry corresponding to a physical storage location at which data is stored for a data portion of the first logical storage unit at a particular point in time. A first virtual snapshot lookup table may be provided for a first portion of the first logical storage unit, the first virtual snapshot lookup table including a plurality of entries, each entry corresponding to a respective data portion of the first logical storage unit and including a reference to a respective entry of the first snapshot pointer structure. The virtual lookup table may correspond to multiple snapshots of the first logical storage unit that have a same value for each data portion of the at least first portion.

公开(公告)号：US20210326217A1

公开(公告)日：2021-10-21

申请号：US16852785

申请日：2020-04-20

Applicant: EMC IP Holding Company LLC

Inventor： Owen Martin ,  Jeffrey Wilson

IPC: G06F11/14 ,  G06F3/06 ,  G06N20/00 ,  G06N3/08

Abstract: Embodiments of the present disclosure relate to autonomous data protection. One or more input/output (I/O) streams can be received by one or more storage devices. One or more snapshots of each storage device can be obtained. One or more anomalies can be identified based on a change rate corresponding to each storage device's memory allocated to store user data included in the I/O streams.