Emc IP Holding Company LLC

Emc Corporation

Dell Products Inc.

Michael C Brundage

Alan Lee Taylor

Nagapraveen Veeravenkata Seela

David Haase

Paul Thomas McGrath

Somnath A Gulve

Yan Xu

Dayanand Suldhal

Michael Paul Wagner

William C Davenport

Miles Aram De Forest

Walter Forrester

Vasudevan Subramanian

Xiangping Chen

Dennis Thomas Duprey

Peter John McCann

Nagasimha G Haravu

Steven A Morley

Yining Si

Charles Christopher Bailey

Robert F Goudreau

Samuel L Mullis, Ii

Xunce Zhou

Miles Aram DeForest

Kamakshi Viswanadha

Chung-Huy Chen

Piers Yu

Alex Zhongbing Yang

John H Lee

Steve Zhuxiong Ai

Michael J Noeth

Varun K Chinta

Techniques are disclosed for storage resource resynchronization using pending IO requests. For example, a method includes, upon detecting a failed network: quiescing IO activity in progress; identifying storage resources and associated pending IO requests; for each storage resource: creating a first snapshot of the storage resource; for each pending IO request, marking blocks specified by the pending IO request as modified; unquiescing the quiesced IO activity; upon detecting the network has been restored: creating a second snapshot of each storage resource; remote mirroring, to the destination, a copy of differences of each source storage resource to the destination storage resource, wherein the differences are identified by comparing the first and the second snapshot; transmitting a request for the destination to create a third snapshot comprising a snapshot of each destination storage resource; and triggering the destination to process the third snapshot to identify storage resources based on the differences.

Storage resource resynchronization using pending IO requests

Techniques for resynchronizing storage resources of two sites configured for synchronous replication can include tracking in-progress write requests in a map. Responsive to a site failure or a replication link failure resulting in failure or fracture of the synchronous replication, processing can be performed to resynchronize impacted resources of the two sites configured for synchronous replication. The processing can use the in-progress write requests in combination with resource snapshots and snapshot differences to resynchronize the impacted resource of the two sites. In at least one embodiment, the synchronous replication configuration can include active paths between both sites and a host. In at least one embodiment, the synchronous replication configuration can include an active path between the host and one site, and a passive path between the host and the second site. The synchronous replication can be bi-directional or two-way synchronous replication between the two sites.

Techniques for optimized data resynchronization between replication sites

A method performed by a data storage apparatus of maintaining filesystem object attributes in connection with a plurality of drivers is provided. Each driver of the plurality is configured to operate on a respective set of filesystem objects. The method includes (a) for each driver of the plurality, creating a respective driver-specific storage volume; (b) storing, within each driver-specific storage volume, attributes specific to respective filesystem objects operated on by the driver of that driver-specific storage volume; and (c) while operating a particular driver of the plurality on a particular filesystem object, using values of the stored attributes specific to that particular filesystem object operated on by that particular driver. An apparatus, system, and computer program product for performing a similar method are also provided.

Per-service storage of attributes

A method is used in managing storage space in storage systems. Storage space reserved by a storage object from a set of storage tiers is evaluated. A data storage system includes the first and second storage tiers configured such that performance characteristics associated with the first storage tier is different from the second storage tier. Based on the evaluation, storage space available and consumed in each storage tier of the set of storage tiers is determined.

Storage insurance and pool consumption management in tiered systems

Techniques for creating and using snapshots may include: receiving a request to create a new snapshot of a source object; determining whether a first generation identifier associated with the source object matches a second generation identifier associated with a base snapshot of the source object; determining whether the source object has been modified since the base snapshot was created; and responsive to determining the first generation identifier matches the second generation identifier and also determining that the source object has not been modified since the base snapshot was created, associating the new snapshot with the base snapshot thereby indicating that the new snapshot and the base snapshot have matching content and denote a same point in time copy of the source object.

Snapshot performance optimizations

A method, computer program product, and computer system for receiving, at a computing device, a write request from a host, wherein a first portion of a process may receive the write request. A callback and context may be set in the write request by the first portion of the process. The write request may be passed to a second portion of the process. The first process may be provided with the context. The first process may use the context to replicate the write request data to a destination.

System and method for synchronous replication write handling

Techniques are presented for implementing a scalable approach to keeping track of the metadata validity of persistently-stored metadata for storage objects. In contrast with prior approaches, improved techniques only store a list of the invalid (or quarantined) objects rather than all objects regardless of validity of their metadata. Under normal circumstances, only a small number of storage objects are invalid at any given time, as the system generally takes steps to repair the invalid objects in the normal course of operation. Thus, the number of invalid objects tends to be small, barring some catastrophic system failure. Only a small amount of expensive privileged persistent storage is therefore needed. A health level may also be used to indicate many failures, indicative of catastrophic system failure.

Quarantining storage objects using a quarantine list

A technique for copying a source data object within a data storage system to a destination includes ingesting data portions of the source object into respective pages of a cache. The cache associates the pages with respective descriptors and writes into the descriptors locations of storage elements that have been provided for storing the respective data portions at the destination. When later flushing these cache pages, each page is flushed to the location at the destination that is provided in the respective descriptor.

Efficient cloning and migration of data objects

A technique for managing file system expansions includes receiving a request to perform a file system expansion, the request specifying or implying an increase in size of a file system to a new target size. The request is received while a previous file system expansion is already in progress. The technique includes merging the previous file system expansion into the file system expansion specified by the request, to increase the size of the file system to the new target size.

Managing multiple file system expansions

There are disclosed techniques for use in managing data copying. In one embodiment, there is disclosed a method including a number of steps. The method comprises performing a first operation to copy data from a first region of a source area. The method also comprises determining a count relating to pending I/O requests in connection with a second region of the source area upon completion of the first operation. And, in response to determining that the count relating to pending I/O requests in connection with the second region of the source area equals zero, the method further comprises performing a second operation to copy data from the second region of the source area and configuring a new region in the source area to record a count relating to pending I/O requests in connection with the source area.

Method, data storage system and computer program product for managing data copying

A technique for providing access to a data object serving as a target of snapshot-shipping replication includes taking a system snap of the data object after completion of each of multiple snapshot-shipping updates. In response to receiving a request to take a user snap of the data object, a data storage system redirects the request to a previously generated system snap, so that the data storage system takes the user snap of the system snap rather than taking the user snap of the data object itself.

Creating consistent user snaps at destination during replication

A technique for managing copy sessions in a data storage system supports active and inactive copy-session states and reclaims memory for inactive copy sessions to reduce their memory footprints. When a copy session transitions from the active state to the inactive state, the copy session persists certain copy-progress data in non-volatile storage and frees structures in memory previously storing that copy-progress data. The inactive copy session continues to run but performs no copying and consumes less memory. When the copy session later transitions back to the active state, the copy session reads the copy-progress data back into memory and resumes copying.

Managing copy sessions in a data storage system to control resource consumption

A method is used in managing snapshots of data. Identity information of a snapshot of data is updated. The snapshot represents a state of the data at a particular prior point in time. A new snapshot of the data is created. The new snapshot is created based on the identity information of the snapshot.

Managing snapshots of data

A method includes (a) receiving a command to create an upper-deck filesystem of a specified size, the upper-deck filesystem residing within a logical volume expressed from a container file of a lower-deck filesystem, (b) provisioning a plurality of storage provisioning units (SPUs) from a storage pool of the data storage system to the container file in an order reflecting proximity of the SPUs within storage devices of the data storage system, the plurality of SPUs providing storage for the entire container file, and (c) subsequent to provisioning the plurality of SPUs to the container file, executing a plurality of threads in parallel to write metadata of the upper-deck filesystem to the plurality of SPUs, representing the upper-deck filesystem. Other embodiments are directed to a system, a computerized apparatus, and a computer program product for performing methods similar to that described above.

Coordination of file system creation to ensure more deterministic performance characteristics

A technique for providing access to a data object serving as a target of snapshot-shipping replication includes taking a system snap of the data object after completion of each of multiple snapshot-shipping updates. In response to a data storage system receiving an IO (input/output) request to read and/or write to the data object, a data storage system redirects the IO request to a previously generated system snap, so that the data storage system performs the operation specified in the IO request on the system snap rather than of the data object itself.

Growing community of inventors

Cary, NC, United States of America

Michael C Brundage