Netapp, Inc.

Christopher Clark Corey

Daniel David McCarthy

Austino Nicholas Longo

Sneheet Kumar Mishra

Christopher Cason

Ananthan Subramanian

Kevin Daniel Varghese

Abdul Basit

Yash Hetal Trivedi

William Arthur Gutknecht

Swaroop Vikram Choudhari

Chad Edmund Schneider

Techniques are provided for failing over an aggregate from one file system instance to a different file system instance of a distributed scale-out storage system. The aggregate may be stored within distributed storage that is accessible to a plurality of file system instances of the distributed scale-out storage system. When the aggregate is failed over from a first file system instance to a second file system instance, the first file system instance may still have a valid read lease that allows the first file system instance to serve client I/O, directed to the aggregate, using a cache. In order to prevent the first file system instance from serving stale data from the cache before the read lease expires, state machines and a set of control data are used to ensure that the second file system instance attaches to the aggregate only after the read lease has expired.

Aggregate failover for a distributed scale-out storage system

A technique is configured to provide various data protection schemes, such as replication and erasure coding, for data blocks of volumes served by storage nodes of a cluster configured to perform deduplication of the data blocks. Additionally, the technique is configured to ensure that each deduplicated data block complies with data redundancy guarantees of the data protection schemes, while improving storage space of the storage nodes. In order to satisfy the data integrity guarantees while improving available storage space, the storage nodes perform periodic garbage collection for data blocks to optimize storage in accordance with currently applicable data protection schemes.

Storage space optimization in a system with varying data redundancy schemes

A technique provides efficient data protection, such as erasure coding, for data blocks of volumes served by storage nodes of a cluster. Data blocks associated with write requests of unpredictable client workload patterns may be compressed. A set of the compressed data blocks may be selected to form a write group and an erasure code may be applied to the group to algorithmically generate one or more encoded blocks in addition to the data blocks. Due to the unpredictability of the data workload patterns, the compressed data blocks may have varying sizes. A pool of the various-sized compressed data blocks may be established and maintained from which the data blocks of the write group are selected. Establishment and maintenance of the pool enables selection of compressed data blocks that are substantially close to the same size and, thus, that require minimal padding.

Pooling blocks for erasure coding write groups

A bin syncing technique ensures continuous data protection, such as replication and erasure coding, for content driven distribution of data served by storage nodes of a cluster in the event of failure to one or more block services configured to process the data. The cluster maintains information about the block services assigned to host a bin with a copy of the data in a bin assignment table associated with a state. The copies of the data are named, e.g., replica 0 (R0), replica 1 (R1) or replica 2 (R2). In response to failure of one or more block services assigned to host a bin with a replica of the data, an alternate or replacement block service may access the assignments maintained in the bin assignment table, which specify names of the replicas associated with the state.

Bin syncing technique for multiple data protection schemes

Available storage space in a system with varying data redundancy schemes

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Boulder, CO, United States of America

Christopher Clark Corey