Abstract: Machines, systems and methods for enhancing data recovery in a data storage system, the method comprising determining whether one or more data storage mediums in a data storage system are unavailable; determining data that are at a risk of loss, due to said one or more data storage mediums being unavailable; from among the data that is determined to be at the risk of loss, identifying data that is highly vulnerable to loss; and creating one or more temporary replicas of the data that is highly vulnerable to loss.

Abstract: For boosting decompression in the presence of reoccurring Huffman trees, a previous Huffman tree is used to decompress a new data block if a match is identified between a compacted description of the Huffman tree and a recently used Huffman tree compaction.

Abstract: For boosting decompressionin the presence of reoccurring Huffman trees, a compacted description of a Huffman tree is compared to recently used Huffman tree compactions for identifying matches rather than reconstructing a Huffman tree from a header of a compressed block for each data block to avoid overhead of a Huffman tree reconstruction.

Abstract: Exemplary method, system, and computer program product embodiments for efficient one-pass cache-aware compression are provided. In one embodiment, by way of example only, an output of a fast compressor to Huffman encoding for achieving the one-pass cache-aware compression by using a predetermined Huffman-tree upon determining by the fast compressor a final representation of each data byte.

Abstract: For boosting decompression in the presence of reoccurring Huffman trees, a compacted description of a Huffman tree is compared to recently used Huffman tree compactions for identifying matches rather than reconstructing a Huffman tree from a header of a compressed block for each data block to avoid overhead of a Huffman tree reconstruction.

Abstract: For real-time classification of data into data compression domains, a decision is made for which of the data compression domains write operations should be forwarded by reading randomly selected data of the write operations for computing a set of classifying heuristics thereby creating a fingerprint for each of the write operations. The write operations having a similar fingerprint are compressed together in a similar compression stream.

Abstract: Real-time reduction of CPU overhead for data compression is performed by a processor device in a computing environment. Non-compressing heuristics are applied on a randomly selected data sample from data sequences for determining whether to compress the data sequences. A compression potential is calculated based on the non-compressing heuristics. The compression potential is compared to a threshold value. The data sequences are either compressed if the compress threshold is matched, compressed using Huffman coding if Huffman coding threshold is matched, or stored without compression.

Abstract: In accordance with one or more embodiments, an inode implemented file system may be utilized to support both offline and inline deduplication. When the first content is stored in the storage medium, one inode is used to associate a filename with the data blocks where the first content is stored. When a second content that is a duplicate of the first content is to be stored, then a parent inode is created to point to the data blocks in which a copy of the first content is stored. Further, two inodes are created, one representing the first content and the other representing the second content. Both inodes point to the same parent inode that points to the data blocks where the first content is stored.

Abstract: Machines, systems and methods for compression ratio estimation are provided. The method comprises selecting a plurality of sample points in a data stream to compress sample data selected at said sample points according to a first compression method; and computing an average compression ratio contribution over the selected plurality of sample points, wherein compression ratio contribution of a sample point is determined based on the first compression method and data in locality of the sample point, and wherein the locality for the sample point is defined by locations in the data stream, such that said locations potentially affect the sample point's contribution to the compression ratio.

Abstract: Systems and methods for optimizing deduplication in a data storage system are provided. The method comprises associating a first name with first data blocks including first content stored in a data storage system, wherein the first name is associated with the first data blocks by way of a reference to a first meta file that points to a data file which points to the first data blocks; storing a first signature derived from the first content in an indexing data structure, wherein the first signature is used to associate the first name with the first data blocks and as means to verify whether a second content is a duplicate of the first content, based on value of a second signature derived from the second content.

Abstract: Systems and methods for estimating data reduction ratio for a data set is provided. The method comprises selecting a plurality of m elements from a data set comprising a plurality of N elements; associating an identifier hi for each of the plurality of m elements; associating an identifier he for each of the plurality of elements in the data set; tracking number of times an element i appears in a base set that includes the plurality of m elements selected from the data set; calculating a value counti that indicates the number of times an identifier he matches an identifier hi; and estimating data reduction ratio for the plurality of N elements in the data set, based on number of m number elements selected from the data set and the value counti.

Abstract: Systems and methods for estimating data reduction ratio for a data set is provided. The method comprises selecting a plurality of m elements from a data set comprising a plurality of N elements; associating an identifier hi for each of the plurality of m elements; associating an identifier he for each of the plurality of elements in the data set; tracking number of times an element i appears in a base set that includes the plurality of m elements selected from the data set; calculating a value counti that indicates the number of times an identifier he matches an identifier hi; and estimating data reduction ratio for the plurality of N elements in the data set, based on number of m number elements selected from the data set and the value counti.

Abstract: Systems and methods for optimizing deduplication in a data storage system are provided. The method comprises associating a first name with first data blocks including first content stored in a data storage system, wherein the first name is associated with the first data blocks by way of a reference to a first meta file that points to a data file which points to the first data blocks; storing a first signature derived from the first content in an indexing data structure, wherein the first signature is used to associate the first name with the first data blocks and as means to verify whether a second content is a duplicate of the first content, based on value of a second signature derived from the second content.

Abstract: In accordance with one or more embodiments, an inode implemented file system may be utilized to support both offline and inline deduplication. When the first content is stored in the storage medium, one inode is used to associate a filename with the data blocks where the first content is stored. When a second content that is a duplicate of the first content is to be stored, then a parent inode is created to point to the data blocks in which a copy of the first content is stored. Further, two inodes are created, one representing the first content and the other representing the second content. Both inodes point to the same parent inode that points to the data blocks where the first content is stored.

Abstract: A novel and useful method of implementing a full coverage low power mode in a storage system comprised of one or more memory storage devices storing replicated data items. A subset of the memory storage devices is chosen whose replicated data items require the least amount of storage. If the chosen subset stores uncovered data items, these data items are copied to an auxiliary memory storage device. The storage system can enter a full coverage low power mode by powering down the chosen subset of memory storage devices.

Abstract: A novel and useful method of implementing a full coverage low power mode in a storage system comprised of one or more memory storage devices storing replicated data items. A subset of the memory storage devices is chosen whose replicated data items require the least amount of storage. If the chosen subset stores uncovered data items, these data items are copied to an auxiliary memory storage device. The storage system can enter a full coverage low power mode by powering down the chosen subset of memory storage devices.