Emc IP Holding Company LLC

Dell Products Inc.

Shari Vietry

Jason E Raff

David Bernard

Vamsi K Vankamamidi

Joris Johannes Wils

Eric Robert Schott

Paul Anthony Calato

Vikram Prabhakar

Nishant Kanaiyalal Mehta

Timothy D Nolan

Philippe Armangau

Vladimir Shveidel

Bar David

Nimrod Shani

Laco Scott Harvell

Ben Beauregard

A technique is directed to sharing a page of memory among a first processing node and a second processing node. The technique includes provisioning the first processing node with a first queue and the second processing node with a second queue. The technique further includes configuring the first processing node to enqueue, within the first queue, local lock requests to assign lock ownership of the page to the first processing node and peer lock requests to assign lock ownership of the page to the second processing node. The technique further includes configuring the second processing node to enqueue, within the second queue, the peer lock requests to provide lock ownership coordination of the page among the first processing node and the second processing node.

Locking in multi-node environments

A method, computer program product, and computer system for acquiring, by a first node, local locks of the first node associated with a metadata log transaction, wherein the first node acquires the local locks of the first node prior to sending a commit message to a second node. The second node may acquire local locks of the second node associated with the metadata log transaction, wherein the second node acquires the local locks of the second node based upon, at least in part, receiving the commit message from the first node.

System and method for consistent metadata access based on local locks semantics in a multi-node cluster

A method, computer program product, and computer system for receiving an XCopy command is provided. The XCopy command may be in the form of an IO operation. The IO operation may be a subextent block operation. A source range and a destination range of the XCopy command may be determined to be aligned within an alignment boundary. The Xcopy command may be determined to be smaller than a predetermined size. In response to determining the source range and destination range of the XCopy command are aligned within the alignment boundary and the XCopy command is smaller than a predetermined size, the XCopy command may be processed. The receiving of the XCopy command may be recorded in a log.

System and method for efficient implementation of XCopy commands

A method of operating a storage appliance is provided. The method includes (a) in response to the appliance receiving a first command to perform a first storage operation on a first plurality of blocks, storing a command record for each block of the first plurality in a cache, each command record respectively indicating an address of that block; (b) upon flushing the command record for each block of the first plurality from the cache to persistent storage, storing data of that block at its indicated address; (c) in response to the storage appliance receiving a second command to perform a second storage operation on a second plurality of blocks, storing, in the cache, an aggregated command record that indicates the second storage operation and an address range of the second plurality, the second storage operation representing an identical change to all blocks of the second plurality; and (d) upon flushing the aggregated command record from the cache to the persistent storage, performing the storage operation indicated by the aggregated command record over the address range indicated by the aggregated command record.

Selectively processing storage commands at different granularities based on command types

Techniques for in-band locking of extents containing multiple pages of shared non-volatile data storage are disclosed in which inter-node lock request messages indicate both an individual page for which a lock is requested and the multi-page extent that contains that page. A page lock or an extent lock is granted to the requesting node based on the time since the last access to the extent by the node to which the request was sent. A generation number may be maintained in each node and stored in the per-extent lock table entries and per-page lock table entries such that pages accessed by a node within an extent while the extent is in extent-locked access mode may subsequently be accessed by the node during a page-locked access mode for the extent occurring after the extent-locked access mode ends based on page locks created by the node during the extent-locked access mode.

In-band extent locking

A method, computer program product, and computing system for processing a snapshot structure of a storage system, wherein the snapshot structure includes one or more temporal indicators and defines a plurality of elements including one or more snapshots, wherein the one or more temporal indicators are incremented to indicate the point at which a data entry was initially added to the snapshot structure. A snapshot matrix is generated based, at least in part, upon the snapshot structure, wherein the snapshot matrix defines the storage space used by one or more eclipsed elements and associated eclipsing elements.

Storage management system and method

A system and method reduces cleaning overhead in a storage array by establishing owner groups for selectively organizing memory page groups. The method generates a metadata lookup structure to correlate a disk address of the real-time data generated to a logical block address on the select storage volume. Further, the method establishes a current state of the select storage volume as a first owner group that receives reference access to the logical block address associated with the memory page group. The method selectively generates a memory snapshot of the current state of the select storage volume to form a subsequent owner group. Additionally, the method enables the first owner group and the subsequent owner group to reference the logical block address that is associated with the memory page group until a real-time data write provides a new logical block address that is associated with a new memory page group.

Organization and compression of data in storage arrays to reduce cleaning overhead

Techniques for providing a cache-based mechanism for snapshot management and creation in a data storage system. The techniques include creating, in a cache memory, a snapshot of a data volume such that the same data is shared between the data volume and the snapshot, and modifying, in the cache memory, one or more data pages among a plurality of data pages of the data volume. The techniques further include maintaining, on a list in the cache memory, copies of the data pages of the snapshot previously shared with the data volume prior to their modification, and maintaining, in a table in the cache memory, a copy record that contains information describing the relationship between the data volume and the snapshot. The techniques still further include flushing, in log order, the data pages of the snapshot and the copy record of the data volume and the snapshot to a storage device.

Systems and methods of managing and creating snapshots in a cache-based storage system

A method of managing snapshots on a storage system includes a storage controller (1) receiving a request to store a first snapshot associated with a first volume among a plurality of volumes on the storage system and (2) determining if an assigned snapshot reserve space remaining associated with the first volume is less than an amount of space that is required to store the first snapshot. In response to the assigned snapshot reserve space remaining being less than the amount of space required, borrowing snapshot reserve space from at least one of an unused assigned space or an unused unassigned space within the storage system and storing at least a portion of the first snapshot to the borrowed snapshot reserve space.

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Merrimack, NH, United States of America

Shari Vietry