Netapp, Inc.

Microsoft Technology Licensing, LLC

Suhas Prakash

Ling Zheng

Anshul Pundir

Jeffrey S Kimmel

Kayuri Hasmukh Patel

David Brittain Bolen

Richard Paul Testardi

Arun Rokade

Ernie Pistor

Long Yang

Cameron Michael Hall

Described herein is a system and method for performing a clustered coherent cloud read cache without coherency messaging. At a cloud reader agent having a read cache, a request for a particular portion of data is received from a client. The request includes an identifier of the node making the request, a current time on the node making the request, a last stubbed time of the particular portion of data, and/or an identifier of the particular portion of data. When the particular portion of data is stored in the read cache of the cloud reader agent, the cloud reader agent can determine whether the cached particular portion of data is valid based, at least in part, upon the received identifier of the node making the request, the received last stubbed time of the particular portion of data, and/or, a stored time associated with the cached particular portion of data.

Clustered coherent cloud read cache without coherency messaging

A snap restore technique efficiently restores snapshots of storage containers served by a storage input/output (I/O) stack executing on one or more nodes of a cluster. A Small Computer Systems Interface administration layer interacts with a volume layer of the storage I/O stack to manage and implement a snap restore procedure to restore one or more snapshots of a storage container. The storage container may be a logical unit (LUN) embodied as parent volume (active volume) and the snapshot may be represented as an independent volume embodied as read-only copy of the active volume. The snap restore procedure may be configured to allow restoration to a single snapshot of a LUN or restoration of a plurality of LUNs organized as a consistency group from a group of snapshots. Restoration of the LUN from a snapshot involves (i) creation of another independent volume embodied as a read-write copy (clone) of the snapshot, (ii) replacement of the (old) active volume with the clone, (iii) deletion of the old active volume, and (iv) mapping of the LUN to the clone (i.e., a new active volume).

Snapshot restore workflow

A technique efficiently creates a snapshot for a logical unit (LUN) served by a storage input/output (I/O) stack executing on a node of a cluster that organizes data as extents referenced by keys. In addition, the technique efficiently creates one or more snapshots for a group of LUNs organized as a consistency group (CG) and served by storage I/O stacks executing on a plurality of nodes of the cluster. To that end, the technique involves a plurality of indivisible operations (i.e., transactions) of a snapshot creation workflow administered by a Storage Area Network (SAN) administration layer (SAL) of the storage I/O stack in response to a snapshot create request issued by a host. The SAL administers the snapshot creation workflow by initiating a set of transactions that includes, inter alia, (i) installation of barriers for LUNs (volumes) across all nodes in the cluster that participate in snapshot creation, (ii) creation of point-in-time (PIT) markers to record those I/O requests that are included in the snapshot, and (iii) updating of records (entries) in snapshot and volume tables of a cluster database (CDB).

Snapshot creation workflow

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San Jose, CA, United States of America

Suhas Prakash