Emc Corporation

Emc IP Holding Company LLC

Roel Van Der Goot

Victor Salamon

David Lionel Black

Ashish Arun Palekar

Bradford B Glade

Steven Richard Bromling

Wayne T Karpoff

Dale Hagglund

Geoff Hayward

Nathan Bullock

Anshul Chadda

Steve Bromling

Colin D Durocher

A system and method are provided for processing to create distributed volume in a distributed storage system during a failure that has partitioned the distributed volume (e.g. an array failure, a site failure and/or an inter-site network failure). In an embodiment, the system described herein may provide for continuing distributed storage processing in response to I/O requests from a source by creating the local parts of the distributed storage during the failure, and, when the remote site or inter-site network return to availability, the remaining part of the distributed volume is automatically created. The system may include an automatic rebuild to make sure that all parts of the distributed volume are consistent again. The processing may be transparent to the source of the I/O requests.

Creating distributed storage during partitions

Transferring an application from a first site to a second site includes determining that the second site is a destination site for the application, causing writes by the application at the first site to be propagated semi-synchronously to the second site, transferring storage data from the first site to the second site, suspending operation of the application on the first site, and resuming operation of the application on the second site. The application may be a virtual machine or a host cluster capable of transitioning applications between cluster nodes. The virtual machine may be transferred from the first site to the second site by transferring an image of the virtual machine from the first site to the second site. The destination site may be selected by a user. The second site may be located remotely from the first site across an asynchronous distance.

Migrating applications over asynchronous distances using semi-synchronous acceleration

A system for operating a virtual machine using a first site and a second site of an active/active system is provided. A host cluster and a director cluster may be identified at each of the first site and the second site. A first link may be provided between the host clusters of the first and second sites. A second link may be provided between the director clusters of the first site and second sites. While the virtual machine is operating on the first site, storage data may be transferred from the first site to the second site. An image of the virtual machine may be transferred from the first site to the second site. At least one of the following may be performed: (i) the storage data is transferred using the first link or (ii) the image of the virtual machine is transferred using the second link.

Increased distance of virtual machine mobility over asynchronous distances

The system described herein provides for unifying the streams of I/O, external VM snapshot triggers and VM internal operations into one in connection with providing for snapshotting of both the data storage of a storage system and one or more associated VMs over time. The system described herein thereby allows recording undo and redo journals for all the streams substantially simultaneously. The system described herein unifies snapshots for data storage and all associated VMs in response to one or more triggers. A tag of the unified snapshots may therefore automatically refer to a point-in-time of both the VM and array data.

Unified virtual machine and data storage snapshots

A system for providing mobility of a virtual machine between a first site and a second site of an active/active system is disclosed. For a virtual machine operating on the first site, it may be determined that the second site is a destination site between the first site and the second site. While the virtual machine is operating on the first site, storage data may be transferred from the first site to the second site. Operation of the virtual machine may be suspended on the first site. Operation of the virtual machine may be resumed on the second site. In the event of link failure between the first site and the second site, operation of the virtual machine may be maintained on the second site.

Active/active storage and virtual machine mobility over asynchronous distances

A system for providing prior operation states of a virtual machine in a storage system having at least one storage array is provided. It may be determined that a trigger for taking a snapshot image of the virtual machine and a snapshot of a storage array state has occurred. The snapshot image of the virtual machine may be taken. The snapshot of the storage array state may be taken. The snapshot image of the virtual machine and the snapshot of the storage array state may be made available for subsequent access to rollback the virtual machine and storage array state to a prior state.

Synchronized taking of snapshot memory images of virtual machines and storage snapshots

A system for responding to a failure in an active/active system is provided. It may be determined that a failure has occurred in connection with a first site and a second site. A winning site and a losing site may be determined from among the first site and the second site. It may be determined whether to perform at least one of: a push operation, a pull operation or both to obtain or identify data from the losing site in order to maintain I/O operations on the data at the winning site. A message may be sent to the losing site concerning the data. The message may depend on whether to perform the push operation, the pull operation or both. A response to the message may be received.

Utilizing both application and storage networks for distributed storage over asynchronous distances

Maintaining data at a failover site includes an application writing data at a primary site corresponding to the failover site, where data is transferred asynchronously from the primary site to the failover site, the application issuing an application check point and initiating a system check point in response to the application issuing the application check point, where the system check point causes data at the failover site to be consistent with the primary site. The application check point may complete only after the system check point completes. The application check point may complete independently of completion of the system check point. The application check point may complete either only after the system check point completes or independently of completion of the system check point according to a specific criteria.

Asymmetric asynchronous mirroring for high availability

A data processing system includes a storage system and caching storage controllers coupled to the storage system and to a storage network. The storage controllers operate in an active-active fashion to provide access to volumes of the storage system from any of the storage controllers in response to storage commands from the storage network. The storage controllers employ a distributed cache protocol in which (a) each volume is divided into successive chunks of contiguous blocks, and (b) either chunk ownership may be dynamically transferred among the storage controllers in response to the storage commands, or storage commands sent to a non-owning controller may be forwarded to the owning controller. A multipathing initiator such as a server computer directs the storage commands to the storage controllers by (1) for each volume, maintaining a persistent association of the chunks of the volume with respective storage controllers, and (2) for each storage request directed to a target chunk, identifying the storage controller associated with the target chunk and sending a corresponding storage command to the identified storage controller. Chunk ownership tends to stabilize at individual storage controllers, reducing unnecessary transfer of cache data and metadata among the storage controllers.

Data processing system using cache-aware multipath distribution of storage commands among caching storage controllers

In a distributed RAID-1 (DR1) copy operation, operation of source and target DR1 volumes is first converted to a local-copy operating mode in which the distributed copy operation is converted into a set of local copy operations. Each t is performed at a respective location of the disks of the DR1 volumes and involves copying data of the source DR1 from a first disk to a second disk via a local second communication channel of relatively high bandwidth. Following conversion, the local copy operations are performed at the locations. Upon completion of the local copy operations, storage operations to the source and target DR1 volumes are temporarily suspended, operation of the source and target DR1 volumes is converted back to the normal operating mode, and storage operations to the source and target DR1 volumes are resumed.

Distributed data storage system using local copy operations for RAID-1 volumes

A data processing system is distributed across a plurality of locations coupled together by a wide-area communications network and includes physical storage devices and a set of host computers distributed across the locations. Each host executes both a local initiator application and a local caching storage controller (CSC) application. The CSC applications (1) define a set of block devices presented to the initiator applications for block-oriented data storage operations, the block devices being virtual devices utilizing the underlying physical storage devices, (2) engage in a distributed cache coherence protocol to present the block devices consistently to the initiator applications, (3) in response to a local block storage read command from an initiator application, retrieve the requested data from the local CSC application's cache, from a remote CSC application's cache, or from a physical storage device, and (4) in response to a local block storage write command from an initiator application, invalidate all currently cached user data for the locations/addresses associated with the write command, and either store the user data associated with the write in one or more local or remote CSC application's caches or write the user data to one or more local or remote physical storage devices.

Growing community of inventors

Edmonton, Canada

Roel Van Der Goot