Abstract: An extent-based storage architecture is implemented by a storage server. The storage server generates a new extent identifier for cloning a source extent identified by a source extent identifier and stored at a source data structure that includes a length value providing a length of the source extent, an offset value and a reference count value that provides a number of data containers that reference the source extent identifier. The storage server updates a data structure for a cloned version of the data container for storing the new extent identifier that points to the source extent identifier and includes an extent length value and offset value different from length value and the offset value of the source data structure.

Abstract: A method and system for performing data manipulation on a storage device is disclosed. A data manipulation command is created on a computing device, wherein the computing device is separate from the storage device. The computing device is a client or a server that requests services of a storage system to store data on a storage medium. The computing device and the storage device are connected over a network. The computing device executes a host application, and its data is stored on the medium. The computing device issues a command to the storage device to be performed on the data. The storage device executes the command and sends the result to the computing device. As a result, the data is not sent to the computing device for manipulation.

Abstract: A system and method for transparently compressing file system data using compression group descriptors is provided. When data contained within a compression group be compressed beyond a predefined threshold value, a compression group descriptor is included in the compression group that signifies that the data for the group of level 0 blocks is compressed into a lesser number of physical data blocks. When performing a read operation, the file system first determines the appropriate compression group that contains the desired data and determines whether the compression group has been compressed. If so, the file system decompresses the data in the compression group before returning the decompressed data. If the magic value is not the first pointer position, then the data within the compression group was previously stored in an uncompressed format, and the data may be returned without performing a decompression operation.

Abstract: A method and system for eliminating the redundant allocation and deallocation of special data on disk, wherein the redundant allocation and deallocation of special data on disk is eliminated by providing an innovate technique for specially allocating special data of a storage system. Specially allocated data is data that is pre-allocated on disk and stored in memory of the storage system. “Special data” may include any pre-decided data, one or more portions of data that exceed a pre-defined sharing threshold, and/or one or more portions of data that have been identified by a user as special. For example, in some embodiments, a zero-filled data block is specially allocated by a storage system. As another example, in some embodiments, a data block whose contents correspond to a particular type document header is specially allocated.

Abstract: Method and system for partially cloning a data container with compression is provided. A storage operating system determines if a portion of a source data container that is to be cloned includes a plurality of compressed blocks that are compressed using a non-variable compression group size. The operating system clones the plurality compressed blocks with the non-variable compression group size and de-compresses a plurality of blocks of the data container that are not within the non-variable compression group size. The plurality of compressed blocks and the plurality of blocks that are not within the non-variable compression group size are then stored as a partially cloned copy of the source data container.

Abstract: A method for efficiently handling partial write requests in a storage system includes allocating a new block of data for the new partial data, and allocating a record in an extent map to record the location of the new partial data block, the location of the old partial data block and the offset length for each data block. Data blocks can be repackaged in the background when system resources are available. A full, but misaligned write request is also efficiently handled by writing the new data to a newly allocated data block and allocating new records in an extent map to record information corresponding to two partial write operations.

Abstract: Overwriting part of compressed data without decompressing on-disk compressed data is includes by receiving a write request for a block of data in a compression group from a client, wherein the compression group comprises a group of data blocks that is compressed, wherein the block of data is uncompressed. The storage server partially overwrites the compression group, wherein the compression group remains compressed while the partial overwriting is performed. The storage server determines whether the partially overwritten compression group including the uncompressed block of data should be compressed. The storage server defers compression of the partially overwritten compression group if the partially overwritten compression group should not be compressed. The storage server compresses the partially overwritten compression group if the partially overwritten compression group should be compressed.

Abstract: The present invention provides a system and method for estimating duplicate data in a storage system. A duplicate estimation application executes on a client of a storage system selects an element from an intended destination such as, e.g., a data store of the storage system. If the element is a file (or other data container), the application reads data from the file and computes a fingerprint of the read data. The computed fingerprint is then logged in a fingerprint database, which is illustratively stored on a storage device connected to the client executing the application. This process repeats until the entire file (or other data container) has been read and fingerprinted. Once all elements have been scanned, fingerprinted and recorded, the application identifies any unique entries within the fingerprint database. Utilizing this information, the application computes an estimated space savings that may be realized by employing a data de-duplication technique.

Abstract: A request is received to remove duplicate data. A log data container associated with a storage volume in a storage server is accessed. The log data container includes a plurality of entries. Each entry is identified by an extent identifier in a data structures stored in a volume associated with the storage server. For each entry in the log data container, a determination is made if the entry matches another entry in the log data container. If the entry matches another entry in the log data container, a determination is made of a donor extent and a recipient extent. If an external reference count associated with the recipient extent equals a first predetermined value, block sharing is performed for the donor extent and the recipient extent. A determination is made if the reference count of the donor extent equals a second predetermined value. If the reference count of the donor extent equals the second predetermined value, the donor extent is freed.

Abstract: A method and system for eliminating the redundant allocation and deallocation of special data on disk, wherein the redundant allocation and deallocation of special data on disk is eliminated by providing an innovate technique for specially allocating special data of a storage system. Specially allocated data is data that is pre-allocated on disk and stored in memory of the storage system. “Special data” may include any pre-decided data, one or more portions of data that exceed a pre-defined sharing threshold, and/or one or more portions of data that have been identified by a user as special. For example, in some embodiments, a zero-filled data block is specially allocated by a storage system. As another example, in some embodiments, a data block whose contents correspond to a particular type document header is specially allocated.

Abstract: A method and system for performing data manipulation on a storage device is disclosed. A data manipulation command is created on a computing device, wherein the computing device is separate from the storage device. The computing device is a client or a server that requests services of a storage system to store data on a storage medium. The computing device and the storage device are connected over a network. The computing device executes a host application, and its data is stored on the medium. The computing device issues a command to the storage device to be performed on the data. The storage device executes the command and sends the result to the computing device. As a result, the data is not sent to the computing device for manipulation.

Abstract: An extent-based storage architecture is implemented by a storage server receiving a read request for an extent from a client, wherein the extent includes a group of contiguous blocks and the read request includes a file block number. The storage server retrieves an extent identifier from a first sorted data structure, wherein the storage server uses the received file block number to traverse the first sorted data structure to the extent identifier. The storage server retrieves a reference to the extent from a second sorted data structure, wherein the storage server uses the retrieved extent identifier to traverse the second sorted data structure to the reference, and wherein the second sorted data structure is global across a plurality of volumes. The storage server retrieves the extent from a storage device using the reference and returns the extent to the client.

Abstract: Overwriting part of compressed data without decompressing on-disk compressed data is implemented by receiving a write request for a block of data in a compression group from a client, wherein the compression group comprises a group of data blocks that is compressed, wherein the block of data is uncompressed. The storage server partially overwrites the compression group, wherein the compression group remains compressed while the partial overwriting is performed. The storage server determines whether the partially overwritten compression group including the uncompressed block of data should be compressed. The storage server defers compression of the partially overwritten compression group if the partially overwritten compression group should not be compressed. The storage server compresses the partially overwritten compression group if the partially overwritten compression group should be compressed.

Abstract: A storage server is configured to receive a request to store a data block from a client. The request to store the data block is serviced by the storage server by compressing the data block into a compression group, which includes a number of compressed data blocks. The storage server stores the compression group in a non-volatile memory and flushes the compression group from the non-volatile memory to a physical storage device in response to reaching a consistency point. By compressing data to be stored in system memory of a storage server, the amount of data that can be processed during a given time period by a data storage system is increased. Furthermore, an increase in performance can be achieved at a lower cost, since the cost of additional physical system memory modules can be avoided.

Abstract: A method and system for eliminating the redundant allocation and deallocation of special data on disk, wherein the redundant allocation and deallocation of special data on disk is eliminated by providing an innovate technique for specially allocating special data of a storage system. Specially allocated data is data that is pre-allocated on disk and stored in memory of the storage system. “Special data” may include any pre-decided data, one or more portions of data that exceed a pre-defined sharing threshold, and/or one or more portions of data that have been identified by a user as special. For example, in some embodiments, a zero-filled data block is specially allocated by a storage system. As another example, in some embodiments, a data block whose contents correspond to a particular type document header is specially allocated.

Abstract: A request is received to remove duplicate data. A log data container associated with a storage volume in a storage server is accessed. The log data container includes a plurality of entries. Each entry is identified by an extent identifier in a data structures stored in a volume associated with the storage server. For each entry in the log data container, a determination is made if the entry matches another entry in the log data container. If the entry matches another entry in the log data container, a determination is made of a donor extent and a recipient extent. If an external reference count associated with the recipient extent equals a first predetermined value, block sharing is performed for the donor extent and the recipient extent. A determination is made if the reference count of the donor extent equals a second predetermined value. If the reference count of the donor extent equals the second predetermined value, the donor extent is freed.

Abstract: A storage server is configured to receive a request to store a data block from a client. The request to store the data block is serviced by the storage server by compressing the data block into a compression group, which includes a number of compressed data blocks. The storage server stores the compression group in a non-volatile memory and flushes the compression group from the non-volatile memory to a physical storage device in response to reaching a consistency point. By compressing data to be stored in system memory of a storage server, the amount of data that can be processed during a given time period by a data storage system is increased. Furthermore, an increase in performance can be achieved at a lower cost, since the cost of additional physical system memory modules can be avoided.

Abstract: A method and system for estimating space in a compressed volume to enable a storage server to respond to write requests before actually compressing and/or allocating data on disk. In some embodiments, in response to receiving a request to store data, the storage server estimates the amount of storage space required to store the data on disk. The storage server compares the estimated amount with the amount of available disk space. When the amount of available disk space is less than the estimated space, the storage server sends a response indicating that the request failed. Otherwise, when the amount of available disk space is greater than or equal to the estimate space, the storage server sends a response indicating that the request succeeded. The response is sent before the storage server allocates any disk space in connection with the request.

Abstract: An extent-based storage architecture is implemented by a storage server receiving a read request for an extent from a client, wherein the extent includes a group of contiguous blocks and the read request includes a file block number. The storage server retrieves an extent identifier from a first sorted data structure, wherein the storage server uses the received file block number to traverse the first sorted data structure to the extent identifier. The storage server retrieves a reference to the extent from a second sorted data structure, wherein the storage server uses the retrieved extent identifier to traverse the second sorted data structure to the reference, and wherein the second sorted data structure is global across a plurality of volumes. The storage server retrieves the extent from a storage device using the reference and returns the extent to the client.

Abstract: Systems, computer-readable media storing instructions, and methods can infer a state of behavior. Such a method can include constructing a graph including nodes representing hosts and domains based on an event dataset. The graph can be seeded with information external to the event dataset. A belief whether each of the nodes is in a particular state of behavior can be calculated based on marginal probability estimation.