Abstract: A system and method for writing data segments to a backup storage medium. Data segments are sent from multiple clients to a shared backup server. The backup server writes the data segments for each client into separate container files and then flushes the data from the container files into the backup storage medium. After backing up all of the data segments from a single client, the server commits the transaction which includes flushing newly written data from any open files, closing the open files, and updating metadata for the newly written data. To reduce the amount of time needed to commit the transaction, the backup server flushes and closes container files prior to transaction commit time.

Abstract: Various methods and systems for protecting against chosen plaintext attacks when encrypting data for storage on an untrusted storage system are disclosed. One method involves generating an encryption key for use in encrypting data and generating an identifier for the data. Generation of the encryption key is based upon a hash of the data to be encrypted. The method also involves detecting whether an encrypted copy of the data is already stored by a storage system, based upon the identifier. The method also modifies the data to be encrypted or the encryption key, based upon a client-specific value, prior to generating the identifier.

Abstract: A system, method, and computer program product for backing up data from a backup source to a central repository using deduplication, where the data comprises source data segments is disclosed. A fingerprint cache comprising fingerprints of data segments stored in the central repository is received, where the data segments were previously backed up from the backup source. Source data fingerprints comprising fingerprints (e.g., hash values) of the source data segments are generated. The source data fingerprints are compared to the fingerprints in the fingerprint cache. The source data segments corresponding to fingerprints not in the fingerprint cache may not be currently stored in the central repository. After further queries to the central repository, one or more of the source data segments are sent to the central repository for storage responsive to comparison.

Abstract: A system and method for caching fingerprints in a client cache is provided. A data object that comprises a set of data segments and describes a backup process is identified. Thereafter, a request referencing the data object is made to a deduplication server to request that a task identifier be added to the data object. If the deduplication server is able to successfully add the task identifier to the data object, then an active identifier is added to each data segment from the set of data segments in a cache that is within a client system.

Abstract: A computer-implemented method for providing increased scalability in deduplication storage systems may include (1) identifying a database that stores a plurality of reference objects, (2) determining that at least one size-related characteristic of the database has reached a predetermined threshold, (3) partitioning the database into a plurality of sub-databases capable of being updated independent of one another, (4) identifying a request to perform an update operation that updates one or more reference objects stored within at least one sub-database, and then (5) performing the update operation on less than all of the sub-databases to avoid processing costs associated with performing the update operation on all of the sub-databases. Various other systems, methods, and computer-readable media are also disclosed.

Abstract: A computer-implemented method for removing unreferenced data segments from deduplicated data systems may include: 1) identifying a deduplicated data system that contains a plurality of data segments, 2) identifying a plurality of containers within the deduplicated data system, with each container containing a subset of the data segments within the deduplicated data system, 3) identifying at least one container within the plurality of containers that is likely to include a large proportion of data segments that are not referenced by data objects within the deduplicated data system, and then, for each identified container, 4) searching for unreferenced data segments within the identified container and 5) removing the unreferenced data segments from the identified container. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: A computer-implemented method for removing unreferenced data segments from deduplicated data systems may include: 1) identifying a deduplicated data system that contains a plurality of data objects, 2) dividing the data objects within the deduplicated data system into a plurality of data object groups, 3) identifying, within the data object groups, at least one data object group that has changed subsequent to a prior garbage-collection operation that removed data segments that were not referenced by data objects within the deduplicated data system, 4) identifying at least one container within the deduplicated data system that contains data segments referenced by data objects within the changed data object group, and then, for each identified container, 5) removing data segments from the identified container that are not referenced by data objects within the deduplicated data system. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: A method and system for improving performance with single-instance-storage volumes by leveraging data locality is provided. A client provides a set of fingerprints generated from data segments to be saved to a single-instance storage volume and receives the information on whether a data segment exists on the single-instance storage volume and where it is stored if a data segment exists. Based on its received information, the client determines if a number of non-sequential accesses of a computer-readable medium for the set of segments from the single-instance-storage volume exceeds a predetermined threshold. If so, the client provides the whole set of data segments for storage within the single-instance storage volume regardless of whether or not the data segments are duplicate data segments. These sent data segments will be stored contiguously within the single-instance storage volume while the duplicates will be removed from their previous stored locations.

Abstract: A system and method for storing a data object in a single-instance storage system are described. The data object may be deconstructed into a template and one or more values. If the template is not already stored in the single-instance storage system then it may be stored. Otherwise an existing copy of the template may be referenced. Similarly, existing copies of the values may be referenced if they are already present, or otherwise the values may be stored. Reconstruction information useable to reconstruct the data object may also be stored. The reconstruction information may reference the template and the one or more values stored in the single-instance storage system.

Abstract: A method and system for efficient space management for single-instance-storage volumes is provided. A backup module storing data within a collection of containers according to access locality and retention time of the data, wherein the retention time defines an amount of time the data is stored within the collection of containers before deletion of the data, and the access locality comprises an order in which the data is to be accessed is further provided. A compaction module compacting the stored data by selecting at least two containers among the collection of containers, wherein the selection is performed using a predetermined criteria that includes access locality and retention time of the data is also provided. The compaction module distributes the data among the at least two containers. The compaction criteria creates an imbalance among the containers to create more empty, full, or nearly full containers.

Abstract: A computer-implemented method for removing unreferenced data segments from deduplicated data systems may include: 1) identifying a deduplicated data system that contains a plurality of data objects, 2) dividing the data objects within the deduplicated data system into a plurality of data object groups, 3) identifying, within the data object groups, at least one data object group that has changed subsequent to a prior garbage-collection operation that removed data segments that were not referenced by data objects within the deduplicated data system, 4) identifying at least one container within the deduplicated data system that contains data segments referenced by data objects within the changed data object group, and then, for each identified container, 5) removing data segments from the identified container that are not referenced by data objects within the deduplicated data system. Various other methods, systems, and computer-readable media are also disclosed.

Abstract: A method, system, and computer-readable storage medium are disclosed for sharing non-distributed, random-access storage resources among a plurality of computer systems. A first backup or restore operation may be initiated. In response to initiation of the first backup or restore operation, a volume of a random-access storage device may be automatically mounted at a first computer system. The random-access storage device may be coupled to the first computer system by a network, and the volume may store a non-distributed file system. The first backup or restore operation may be completed by transmitting a first set of data between the random-access storage device and the first computer system. In response to completion of the first backup or restore operation, the volume of the random-access storage device may be automatically unmounted at the first computer system.

Abstract: Method and apparatus for file-level restore from raw partition backups. A backup mechanism may be provided that is configured to perform raw partition backups to a media server and to support file-level restores from the raw partition backups through, for example, Fibre Channel (FC) or iSCSI Logical Unit (LUN) export of the raw partition backup images to client systems. Once a LUN is exported and mounted on the client system, direct file manipulation using standard file system commands may be performed. Embodiments achieve both fast backup and individual file retrieval without the necessity of understanding native file system formats and without requiring a file system mapping of the source (client) partition. Thus, embodiments may be used in heterogeneous environments.

Abstract: A de-duplication storage system which uses multiple indices is described. A first group of one or more indices may be stored in random access memory (RAM) or another type of fast storage. A second group of one or more indices may be stored on one or more disk drives or another type of storage where large amounts of data can be stored inexpensively. The first group of indices may be used when adding new files to the de-duplication storage system in order to determine whether the file segments of the new files are already stored. The second group of indices may be used when restoring files in order to lookup the segments of the files.

Abstract: A system, method, and computer program product for backing up data from a backup source to a central repository using deduplication, where the data comprises source data segments is disclosed. A fingerprint cache comprising fingerprints of data segments stored in the central repository is received, where the data segments were previously backed up from the backup source. Source data fingerprints comprising fingerprints (e.g., hash values) of the source data segments are generated. The source data fingerprints are compared to the fingerprints in the fingerprint cache. The source data segments corresponding to fingerprints not in the fingerprint cache may not be currently stored in the central repository. After further queries to the central repository, one or more of the source data segments are sent to the central repository for storage responsive to comparison.

Abstract: Various embodiments of a computer system and methods are disclosed. In one embodiment, a computer system includes a host coupled to a backup store. The host backs up a dataset to the backup store. The dataset comprises data entities and application-specific metadata describing the data entities. The application-specific metadata enables an application to use the data entities. The host: mounts the backup store for read/write access by the application, accesses the backup store with the application, selects a data entity, and performs an operation on the data entity in the backup store using the application. The operation may comprise verifying that the data entity is valid and usable in the context of the application or creating an archival backup of the data entity on a backup medium. The backup store may be a disk-based backup store and the backup medium may be a tape-based backup medium.

Abstract: Various embodiments of a computer system and methods are disclosed. In one embodiment, a computer system includes hosts coupled to a backup medium. The backup medium stores data segments and objects, each object referencing one or more segments. A second host conveys a write request to a first host identifying a data entity comprising segments referenced by a first object. The first host restores a copy of the data entity and creates a second object referencing the segments that were referenced by the first object in response to receiving the write request. The first host adds segment references to the second object in response to receiving a change that adds data to the copy or deletes a portion of a segment from the copy. The first host removes a segment reference from the second object if a change deletes all of a segment from the copy.

Abstract: Various embodiments of systems and methods for performing volume-based incremental backups are disclosed. A method may involve generating a snappoint of a volume. The snappoint indicates which portions (e.g., blocks or extents) of the volume have been modified between a time at which the snappoint was generated and a time at which a subsequent snappoint was generated. The method may also involve accessing information mapping the file to the volume and, if the snappoint identifies as having been modified any blocks of the volume to which the file maps, copying those blocks from the subsequent snappoint to the backup device. Portions not identified as having been modified by the snappoint are not copied. Program instructions implementing such a method may be stored on a computer accessible medium.

Abstract: Methods and systems to backup data are provided. A first computing device identifies data to backup and stabilizes a frozen image of that data. Next, the frozen image is decomposed into physical storage addresses housing the data. The decomposed storage addresses are sent to a second computing device. The second computing device uses the storage addresses along with existing operating system I/O operations to backup the data to computer readable media.

Abstract: A Storage Mapping Driver (SMD) that provides a system and method for determining the application host storage locations of file data so that the file data can be later backed up directly from its storage media. The application host location of the file data is sent to the backup host either just prior to a backup or as the information is obtained. In this way the backup host is capable of backing up the files without reference to systems on the application host such as the file system manager and the volume manager. The SMD invokes the file system manager and/or the volume manager to read a file to be backed up in order to obtain a file map. If the host system does not have a file system manager and/or a volume manager, a backup file system manager is provided, which is invoked by the SMD to read a file to obtain a file map for use during a backup.