Abstract: A method, computer program product, and computing system for receiving a candidate data portion; calculating a distance-preserving hash for the candidate data portion; and performing an entropy analysis on the distance-preserving hash to generate a hash entropy for the candidate data portion.

Abstract: Methods and apparatus are provided for reporting space savings due to data reduction in storage systems. An exemplary method comprises establishing a leaf pointer for a plurality of allocation units of data in a storage system; for at least a first allocation unit of data matching a second allocation unit of data, replacing the leaf pointer for the first allocation unit with a deduplication pointer to the leaf pointer of the second allocation unit; determining a total number of pointers as a sum of a number of the leaf pointers and a number of the deduplication pointers; determining a difference between the total number of pointers and the number of leaf pointers; and providing a data reduction attributed to deduplication based on the difference. The allocation units of data are optionally also compressed. Data reduction attributed to the compression can optionally be determined independent of the data reduction attributed to the deduplication.

Abstract: Methods and apparatus are provided for reporting space savings due to pattern matching in storage systems. An exemplary method comprises, when a given allocation unit in a storage system matches one or more predefined patterns, (i) setting a corresponding pattern flag for the given allocation unit, and (ii) incrementing at least one pattern counter; generating at least one snapshot of at least a portion of a file comprising the given allocation unit; and determining a data reduction attributed to pattern matching based on the at least one pattern counter, wherein the one or more predefined patterns in the at least one snapshot are excluded from the data reduction attributed to pattern matching.

Abstract: A method is used in managing inline data compression in storage systems. A number of allocation units in which data of a file system is stored in a segment in a compressed format is determined. The segment comprises of a first storage space for storing a set of allocation units and a second storage space that is not allocated to the set of allocation units. Based on a policy, the second storage space of the segment is associated to at least one allocation unit of the set of allocation units.

Abstract: A data access pattern is determined by a file system mapping component for prefetching data for performing I/O requests on the data. Information associated with determination of the data access pattern is provided by the file system mapping component to a block mapping component. Based on the information, prefetching of data is managed by the block mapping component from a storage device for performing the I/O requests.

Abstract: A method is used in managing truncation of files of file systems. A request is received to delete a portion of a file of a file system. A set of extents associated with the portion of the file is determined where the file has been identified for deletion. A replica of the set of extents is created. The replica represents a state of the set of extents at a particular prior point in time. The portion of the file is deleted by updating metadata of the file. The replica is asynchronously deleted in background.

Abstract: A method is used in managing truncation of files of file systems. A request is received to delete a portion of a file of a file system. A replica of the file is created. The replica represents a state of the file at a particular prior point in time. The replica shares a set of file system blocks of the file with the file. The portion of the file is deleted by updating metadata of the file. The replica of the file is asynchronously deleted in background by de-allocating the set of file system blocks.

Abstract: A method is used in managing inline data compression in storage systems. A request is received to update data of a data object previously stored in an allocation unit of a segment in a storage system. The segment comprises of a set of allocation units in a compressed format. A determination is made as to whether the updated data of the data object can be stored in the compressed format in the allocation unit of the segment. Based on the determination, the updated data is written in the compressed format to the allocation unit of the segment.

Abstract: A method is used in managing inline data compression in storage systems. A request is received to update data of a data object previously stored in an allocation unit of a segment in a storage system. The segment comprises of a set of allocation units in a compressed format. A determination is made as to whether the updated data of the data object can be stored in the compressed format in the allocation unit of the segment. Based on the determination, a free allocation unit is selected from a list of free allocation units managed by the storage system for writing the updated data in the compressed format to the free allocation unit.

Abstract: A method is used in managing mounting of file systems. A request is received to mount a file system. The request to mount the file system is added in a pending file system mounts queue based on a policy. The file system is mounted in background. Access to the file system is provided before mounting the file system.

Abstract: Directory attributes are provided so that the time for creating an incremental backup of a file system by a scan of the file system tree is proportional generally to the number of files that change between backups instead of the number of files in the file system. A tree modification attribute indicates whether or not any file in a directory tree has changed since the last backup. If no file has changed in the directory tree, then the entire tree is skipped during the scan for changed files. In addition, a list is compiled of the files in the directory that represent branches having at least one changed file, so that the list is scanned instead of the directory entries. When a file is changed for the first time since the last backup, the file is queued so that the directory attributes are updated in a background process.

Abstract: Implementations are provided herein relating to adaptive prefetch for predicted write requests. A set of I/O requests associated with a set of storage devices and a set of cache memory can be monitored. Through the application of a prefetch algorithm to the set of monitored I/O requests, future write requests can be predicted. Data blocks corresponding to the predicted future write requests can be read in parallel with other disk I/O and preloaded into cache for access by, for example, data protection processes. In this sense the efficiency of data protection processes can be enhanced by reducing sequential disk I/O requests.

Abstract: A method is used in managing concurrent I/Os in file systems. A first and second I/O requests are received. The first I/O request is directed to a first portion of a file and the second I/O request is directed to a second portion of the file. A first range lock for the first portion is obtained and a second range lock for the second portion is obtained. The first and second I/O requests are performed concurrently. The second I/O request starts performing I/O on the second portion of the file before the first I/O request finish performing I/O on the first portion of the file.

Abstract: Accordingly a method and interface allows an attribute data base used by an Information Manager to be quickly populated and accurately maintained. A single Bulk Attribute Retrieval Request triggers the primary storage device to collect object attribute information. The method allows for selective collection of objects and attributes by providing filters and attribute lists in the Requests. The Request may be used to provide an incremental scan with appropriate time stamp filtering. In addition, the size of the results can be controlled by the IM by eliminating attributes that are not of interest to the IM. The Request is advantageously issued over a FileMover interface, which is an HTTP connection, and encoded in XML, allowing the IM to easily customize the Request as desired.

Abstract: Accordingly a method and interface allows an attribute data base used by an Information Manager to be quickly populated and accurately maintained. A single Bulk Attribute Retrieval Request triggers the primary storage device to collect object attribute information. The method allows for selective collection of objects and attributes by providing filters and attribute lists in the Requests. The Request may be used to provide an incremental scan with appropriate time stamp filtering. In addition, the size of the results can be controlled by the IM by eliminating attributes that are not of interest to the IM. The Request is advantageously issued over a FileMover interface, which is an HTTP connection, and encoded in XML, allowing the IM to easily customize the Request as desired.