Dell Products Inc.

Quest Software Inc.

Ratna Manoj Bolla

Vinod Jayaraman

Goutham Rao

Mechanisms are provided for adjusting a configuration of data stored in a storage system. According to various embodiments, a storage module may be configured to store a configuration of data. A processor may be configured to identify an estimated performance level for the storage system based on a configuration of data stored on the storage system. The processor may also be configured to transmit an instruction to adjust the configuration of data on the storage system to meet the service level objective when the estimated performance level fails to meet a service level objective for the storage system.

Storage system deduplication with service level agreements

Deduplication dictionaries are used to maintain data chunk identifier and location pairings in a deduplication system. When access to a particular data chunk is requested, a deduplication dictionary is accessed to determine the location of the data chunk and a datastore is accessed to retrieve the data chunk. However, deduplication dictionaries are large and typically maintained on disk, so dictionary access is expensive. Techniques and mechanisms of the present invention allow prefetches or read aheads of datastore (DS) headers. For example, if a dictionary hit results in datastore DS(X), then headers for DS(X+1), DS(X+2), DS(X+read-ahead-window) are prefetched ahead of time. These datastore headers are cached in memory, and indexed by datastore identifier. Before going to the dictionary, a lookup is first performed in the cached headers to reduce deduplication data access request latency.

Intelligent deduplication data prefetching

Techniques and mechanisms described herein facilitate the restoration temporal locality in global and local deduplication storage systems. According to various embodiments, when it is determined that cache memory in a storage system has reached a capacity threshold, each of a plurality of data dictionary entries stored in the cache memory may be associated with a respective merge identifier. Each data dictionary entry may correspond with a respective data chunk. Each data dictionary entry may indicate a storage location of the respective data chunk in the storage system. The respective merge identifier may indicate temporal locality information about the respective data chunk. The plurality of data dictionary entries may be stored to disk memory in the storage system. Each of the stored plurality of data dictionary entries may include the respective merge identifier.

Restoring temporal locality in global and local deduplication storage systems

Techniques and mechanisms are provided to instantly clone active files including active optimized files. When a new instance of an active file is created, a new stub is generated in the user namespace and a block map file is cloned. The block map file includes the same offsets and location pointers that existed in the original block map file. No user file data needs to be copied. If the cloned file is later modified, the behavior can be same as what happens when a de-duplicated file is modified.

Active file Instant Cloning

Deduplication dictionaries are used to maintain data chunk identifier and location pairings in a deduplication system. When access to a particular data chunk is requested, a deduplication dictionary is accessed to determine the location of the data chunk and a datastore is accessed to retrieve the data chunk. However, deduplication dictionaries are large and typically maintained on disk, so dictionary access is expensive. Techniques and mechanisms of the present invention allow prefetches or read aheads of datastore (DS) headers. For example, if a dictionary hit results in datastore DS(X), then headers for DS (X+1), DS (X+2), DS(X+read-ahead-window) are prefetched ahead of time. These datastore headers are cached in memory, and indexed by datastore identifier. Before going to the dictionary, a lookup is first performed in the cached headers to reduce deduplication data access request latency.

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Hyderabad Telangana, India

Ratna Manoj Bolla