Netapp, Inc.

Omprakaash C Thoppai

William Zumach

Richard Parvin Jernigan, Iv

Robert Wyckoff Hyer, Jr

Wesley R Witte

Tianyu Jiang

Raghavendra Chowdary Maddipatla

Wangyuan Zhang

Vinay Sridhar

Alan Stuart Driscoll

Devang Kundanlal Shah

Umeshkumar Vasantha Rajasekaran

Saji Kumar Vijaya Kuman Rajendran Nair Rajendran

Saji Vijaya Rajendran

Techniques for synchronization between data structures for original locks and mirror lock data structures are disclosed herein. The mirror lock data structures are being maintained during various scenarios including volume move and aggregate relocation, in order to preserve the non-disruptive persistent operation on storage initiated by clients. According to one embodiment, a storage node determines a plurality of data container locks to be synchronized to a partner node of the storage node and transfers metadata that indicates states of variables that represent the plurality of data container locks to the partner node in a batch. When a client initiates a data access operation that causes an attempt to modify a data container lock of the plurality of data container locks, the storage node sends a retry code to a client that prompts the client to retry the data access operation after a predetermined time period.

Lock state synchronization for non-disruptive persistent operation

Techniques for notifying clients whose locks did not persist about a loss of lock state after a failover event are disclosed herein. According to one embodiment, a storage node of a high availability cluster constructs a lock data structure based on a mirrored lock data structure for a lock on a data container. The storage node receives a data operation request permitted by the lock from a client to operate on the data container. The storage node instructs to terminate a connection with the client if the lock data structure for the lock on the data container has been recently reconstructed. Accordingly, the client revokes the connection and refrains from committing the locally cached operations to the data container stored in the storage node. The client has an option to reconnect with the cluster and regain the data container privilege controlled by the lock.

Lock state reconstruction for non-disruptive persistent operation

A machine implemented process and system is provided. The process determines if any right granted to an entity for performing an I/O operation associated with a data container stored at a first storage volume is to be revoked. The right itself may be cached at the first storage volume and resident at a second storage volume. A recall message is sent to the node that manages the second storage volume. Any pending I/O operation is completed, after the message is sent and before the right is revoked. Thereafter, the right is revoked and the cached copies of the right are invalidated.

Method and system for revoking rights associated with I/O operations in storage systems

The present invention provides a mechanism for storing and accessing attributes of a data container (e.g., characteristics such as a name of a data container used to perform a lookup operation against the data container) in cache memory within storage systems in a cluster of storage systems. Further, a mechanism is provided so that an attribute of a data container is inserted into a cache memory of preferably one storage system (in the cluster) that caches metadata of the data container (e.g., information describing the data container). As a result, a lookup operation for a data container is directed to and served by the storage system that caches the metadata and the attribute of the data container. The lookup request is not relayed to a storage system that maintains a central directory of attributes of all data containers in the cluster.

Distributing lookup operations in a striped storage system

A technique that provides the ability to copy or move a volume that includes one or more quota structures, by using logical replication, where the volume and any quota structures in it are immediately accessible upon completion of the copy/move operation, and where the quota structures' usage control functionality is immediately functional and reliable upon completion of the copy/move operation. A user does not have to reinitialize the quota mechanism or invoke a quota scanner at the destination.

Transparent transfer of qtree and quota metadata in conjunction with logical replication of user data

The present invention provides a mechanism for storing and accessing attributes of a data container (e.g., characteristics such as a name of a data container used to perform a lookup operation against the data container) in cache memory within storage systems in a cluster of storage systems. Further, a mechanism is provided so that an attribute of a data container is inserted into a cache memory of preferably one storage system (in the cluster) that caches metadata of the data container (e.g., information describing the data container). As a result, a lookup operation for a data container is directed to and served by the storage system that caches the metadata and the attribute of the data container.

A method and system for promoting a snapshot in a distributed striped volume system is provided. A master volume server is configured with a rollback process such that when it is determined that a rollback is required, the master volume server sets a flag persistently in its own raid label on disk. After the persistent flag is set, the master volume server determines a 'common snapshot,' and starts the process of sending RPC messages to each node hosting constituent volumes instructing each constituent volume to roll back to the identified snapshot. When the nodes receive this message a flag is set in the own raid label of each constituent volume and the volume then promotes the particular snapshot. If the master volume server has not received a successful response from each node that the snapshot promotion was successful within a specified time period, there is a retry. The common snapshot is then used as the active file system, thus providing data recovery for the striped volume set.

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Seven Fields, PA, United States of America

Omprakaash C Thoppai