Netapp, Inc.

Vani Vully

Balaji Ramani

Srishylam Simharajan

Avishek Chowdhury

Vasudev Mulchandani

Anil Paul Thoppil

Qinghua Zheng

James Leong

Vitaly Revsin

Jagadish Vasudeva

Parag Deshmukh

Ritika

Deepak Dangi

Raj Kamal

Peter Frank Corbett

Michael Kazar

Susan M Coatney

Richard Parvin Jernigan, Iv

Michael Robin Eisler

Yong Cho

Chaitanya V Patel

Andrew Eric Dunn

Anuja Jaiswal

Vijaya Bhaskar Reddy C H

Ravi Anapindi

A volume rehost tool migrates a storage volume from a source virtual server within a distributed storage system to a destination storage server within the distributed storage system. The volume rehost tool can prevent client access to data on the volume through the source virtual server until the volume has been migrated to the destination virtual server. The tool identifies a set of storage objects associated with the volume, removes configuration information for the set of storage objects, and removes a volume record associated with the source virtual server for the volume. The tool can then create a new volume record associated with the destination virtual server, apply the configuration information for the set of storage objects to the destination virtual server, and allow client access to the data on the volume through the destination virtual server.

Transitioning volumes between storage virtual machines

Systems and methods for reducing read application in a virtual storage system are provided. According to one embodiment, heuristic data may be tracked and utilized in real-time by a file system of the virtual storage system at the level of granularity of a volume, thereby allowing a fast path flag to be enabled/disabled at a volume level during various phases of operation of a workload. The heuristic data for a given volume may be indicative of a correlation between (i) data blocks stored on the given volume being located within a compressible zone of a zoned checksum scheme and (ii) the respective data blocks containing compressed data and a corresponding checksum. Based on the heuristic data, read requests may be selectively directed to the read path (e.g., a fast path or a slow path) expected to mitigate read amplification when data compression is enabled for a zoned checksum scheme.

Read amplification reduction in a virtual storage system when compression is enabled for a zoned checksum scheme

Systems and methods for reducing read application in a virtual storage system are provided. According to one embodiment, read amplification is reduced when AZCS compression is being utilized by avoiding restarting of a read process via a slow path via a RAID layer of the virtual storage system when a data block associated with a read request and obtained via a first fast path read has been found not to be compressed. Instead, a second fast path read may be performed to obtain the corresponding checksum. Alternatively, or additionally, heuristics may be used to predict the odds of the data block being compressed. For example, when information encoded within a PVBN of the data block that identifies the PVBN as being within a compressed AZCS zone has shown to be sufficiently/insufficiently predictive of the data block being compressed, then a flag may be set to enable/disable fast path reads.

A copy-free transition tool converts storage objects from a source format associated with a source storage system to a destination format associated with a destination storage system. The transition tool exports configuration information associated with the source storage system to the destination storage system and brings the storage objects offline. Once the transition tool determines that the storage devices containing the storage objects are physically connected to the destination storage system, the tool can convert file systems from the source format to the destination format while leaving data and file layout unchanged. The tool can also modify metadata associated with each of the storage objects to conform to the destination format and store the modified metadata with the destination storage system.

Converting storage objects between formats in a copy-free transition

A transition tool estimates a cutover time in a copy-free transition of storage objects. The transition tool determines how many storage objects of each type of storage object there are to transition from a source storage system to a destination storage system. The transition tool can measure an operation time for both the source storage system and the destination storage system. The transition tool can estimate an export duration using the source storage system operation time, the number of each type of storage object, and a number of operations for that type of storage object. The transition tool can estimate an import duration using the destination storage system operation time, the number of each type of storage object, and a number of operations for that type of storage object. A total cutover time can then be calculated from the export and import durations.

Calculating cutover time in a copy-free transition of storage objects

A system and method for avoiding object identifier collisions in a cluster environment is provided. Upon creation of the cluster, volume location databases negotiate ranges for data set identifiers (DSIDs) between a first site and a second site of the cluster. Any pre-existing objects are remapped into an object identifier range associated with the particular site hosting the object.

System and method for avoiding object identifier collisions in a peered cluster environment

A system and method addresses data containers in a clustered storage system. Each instantiation of a volume, or other container set, is associated with a data set identifier (DSID). All instantiations of data that represent a single point in time are associated with a master data set identifier (MSID). A volume location database (VLDB), utilizing a replicated database among the nodes of the cluster, stores a data set data structure containing appropriate mapping information between the MSIDs and DSIDs. Clients of the clustered storage system utilize MSIDs to reference data that is desired to be accessed. When a storage system receives a data access request containing a MSID, the storage system accesses the VLDB to identify an appropriate DSID to which to forward the request. The data access request is then forwarded to the appropriate storage system for processing.

System and method for addressing data containers using data set identifiers

Growing community of inventors

Bengaluru, India

Vani Vully