Abstract: A computer-implemented method according to one embodiment includes initiating a read-modify-write (RMW) operation; assigning the RMW operation to a thread; identifying a storage device associated with the RMW operation; assign a log block within the storage device to the thread; determining a free shadow block location within the storage device; creating a copy of data to be written to the storage device during the RMW operation; writing the copy of the data to the free shadow block location within the storage device; updating the log block within the storage device to point to the free shadow block location to which the copy of the data is written; and writing the data to one or more blocks of a home area of the storage device.

Abstract: A computer-implemented method according to one embodiment includes initiating a read-modify-write (RMW) operation; assigning the RMW operation to a thread; identifying a storage device associated with the RMW operation; assign a log block within the storage device to the thread; determining a free shadow block location within the storage device; creating a copy of data to be written to the storage device during the RMW operation; writing the copy of the data to the free shadow block location within the storage device; updating the log block within the storage device to point to the free shadow block location to which the copy of the data is written; and writing the data to one or more blocks of a home area of the storage device.

Abstract: A backup and archival policy method, system, and non-transitory computer readable medium, includes performing correlation analytics to determine identification of a backup policy aligned with a criticality of operational data and backup data including identifying low value backup data having a value less than a predetermined low value threshold, creating a one-time archival of the operational data and the backup data including the low value backup data, and removing the low value backup data from a future data protection policy.

Abstract: A backup and archival policy method, system, and non-transitory computer readable medium, includes performing correlation analytics to determine identification of a backup policy aligned with a criticality of operational data and backup data including identifying low value backup data having a value less than a predetermined low value threshold, creating a one-time archival of the operational data and the backup data including the low value backup data, and removing the low value backup data from a future data protection policy.

Abstract: A backup and archival policy method, system, and non-transitory computer readable medium, includes harnessing of metrics of data classification including both operational data and backup data from an end-to-end stack from a backup Information Lifecycle Governance (ILM) viewpoint.

Abstract: A backup and archival policy method, system, and non-transitory computer readable medium, includes harnessing of metrics of data classification including both operational data and backup data from an end-to-end stack from a backup Information Lifecycle Governance (ILM) viewpoint.

Abstract: An apparatus, system, and method are disclosed for managing storage space allocation. The apparatus includes a recognizing module, a reserving module, and a managing module. The recognizing module recognizes a trigger event at a client of the data storage system. The reserving module reserves logical units of space for data storage. The management module manages the logical units of space at the client. Such an arrangement provides for distributed management of storage space allocation within a storage area network (SAN). Facilitating client management of the logical units of space in this manner may reduce the number of required metadata transactions between the client and a metadata server and may increase performance of the SAN file system. Reducing metadata transactions effectively lowers network overhead, while increasing data throughput.

Abstract: Provided are a method, system, and article of manufacture for applying a policy criteria to files in a backup image. A backup image of files in a file system is maintained. A policy is applied to the files in the backup image to determine files satisfying a policy criteria. A list is prepared indicating the determined files. The determined files in the file system are accessed and a deferred operation indicated in the applied policy is applied to the accessed files in the file system.

Abstract: Provided are a method, system, and article of manufacture for applying a policy criteria to files in a backup image. A backup image of files in a file system is maintained. A policy is applied to the files in the backup image to determine files satisfying a policy criteria. A list is prepared indicating the determined files. The determined files in the file system are accessed and a deferred operation indicated in the applied policy is applied to the accessed files in the file system.

Abstract: Provided are a method, system, and article of manufacture for applying a policy criteria to files in a backup image. A backup image of files in a file system is maintained. A policy is applied to the files in the backup image to determine files satisfying a policy criteria. A list is prepared indicating the determined files. The determined files in the file system are accessed and a deferred operation indicated in the applied policy is applied to the accessed files in the file system.

Abstract: “A system and associated method restore a file system from incremental backups in the presence of deletion, without restoring deleted files. This is accomplished by logging deletions in a deletion log. Using the deletion log, the system re-deletes the deleted files upon a restore operation to an incremental backup epoch. The system the logs deletions so that the files that were deleted and survived a backup epoch have their records logged. The activity log enables an incremental backup from a prior snapshot, and represents a point-in-time version of the file system. The system can either not restore the deleted files, or, alternatively, it can restore the deleted files and then re-deletes them.

Abstract: In a distributed file system the distributed storage management is made useful to a variety of applications. Multiple quality of service options are provided through locking. Three locking systems are provided. The system offers a locking system designed for sequential consistency with write-back caching, typical of distributed file systems. A second locking system is provided for sequential consistency with no caching for applications that manage their own caches. Finally, a locking system that implements a weaker consistency model with write-back caching, designed for efficient replication and distribution of data is included. Locks for replication are suitable for serving dynamic data on the Internet and other highly-concurrent applications. The selection of the appropriate lock protocol for each file is set using the file metadata. Further, a novel locking system is provided for the lock system implementing a weak consistency model with write back caching.

Abstract: A system and method for managing access to assets in a distributed data storage system includes requesting, from a client computer, a lock from a server computer. The lock is evaluated using a bitwise comparison of the protected access modes and restricted access modes defined by the lock with the protected and restricted modes defined by the currently outstanding locks using an algorithm, such that a potentially large compatibility table is not needed.

Abstract: A system, method, and computer program product for a lease-based timeout scheme that addresses fencing's shortcomings. Unlike fencing, this scheme (or protocol) enables an isolated computer to realize it is disconnected from the distributed system and write its dirty data out to storage before its locks are stolen. In accordance with the invention, data consistency during a partition in a distributed system is ensured by establishing a lease based protocol between in the distributed system wherein a client can hold a lease with a server. The lease represents a contract between a client and a server in which the server promises to respect the client for a period of time. The server respects the contract even when it detects a partition between the client and itself.

Abstract: A distributed data storage system for sharing data among client computers running different types of operating systems by separating metadata from data. Data is stored in storage pools that are accessed by the client computers through a storage network. Metadata is stored in a metadata store and provided to the client computers by a cluster of metadata servers. The client computers communicate with the metadata servers using a Storage Tank protocol and over a control network. Each client computer runs an operating system-specific client program that provides the client side functions of the Storage Tank protocol. The client program preferably includes a file system interface for communicating with the file system in the storage system and user applications, a client state manager for providing data consistency, and a plurality of operating system services for communicating with the metadata servers.

Abstract: A data storage system randomly determines a start offset at which to write objects to a storage medium. For updated blocks of the object, e.g., for blocks written during copy-on-write as part of a point-in-time snapshot, the updated block is written in the region of the original file or as close thereto as possible to achieve “virtual contiguity”. Subsequent reads of the object read entire region containing both the object and, potentially, “chaff” data other than the object. The “chaff” data is discarded by the I/O system or file system using, e.g., a bit mask, subsequent to the read.

Abstract: A system and associated method restore a file system from incremental backups in the presence of deletion, without restoring deleted files. This is accomplished by logging the deletions in a deletion log. Using the deletion log, the system re-deletes the deleted files upon a restore operation to an incremental backup epoch. The system the logs deletions so that the files that were deleted and survived a backup epoch have their records logged. The activity log enables an incremental backup from a prior snapshot, and represents a point-in-time version of the file system. The system can either not restore the deleted files, or, alternatively, it can restore the deleted files and then re-deletes them.

Abstract: A system and method for managing access to assets in a distributed data storage system includes requesting, from a client computer, a semi-preemptible access lock from a server computer. The semi-preemptible lock, if granted, is held by the client computer as long as the server does not demand it back, with the client computer granting open instances under non-preemptible file locks for the asset to which the locks pertain as long as the client computer holds the semi-preemptible lock. When another client computer requests the semi-preemptible lock, the server can demand the lock from the holding client, which relinquishes the lock if no open instances are protected by the lock. Otherwise, the holding client computer first attempts to downgrade its lock to meet the request, and if compatibility is not achieved thereby, the holding client refuses to relinquish the lock.

Abstract: In a distributed file system the distributed storage management is made useful to a variety of applications. Multiple quality of service options are provided through locking. Three locking systems are provided. The system offers a locking system designed for sequential consistency with write-back caching, typical of distributed file systems. A second locking system is provided for sequential consistency with no caching for applications that manage their own caches. Finally, a locking system that implements a weaker consistency model with write-back caching, designed for efficient replication and distribution of data is included. Locks for replication are suitable for serving dynamic data on the Internet and other highly-concurrent applications. The selection of the appropriate lock protocol for each file is set using the file metadata. Further, a novel locking system is provided for the lock system implementing a weak consistency model with write back caching.

Abstract: A data storage system randomly determines a start offset at which to write objects to a storage medium. For updated blocks of the object, e.g., for blocks written during copy-on-write as part of a point-in-time snapshot, the updated block is written in the region of the original file or as close thereto as possible to achieve “virtual contiguity”. Subsequent reads of the object read entire region containing both the object and, potentially, “chaff” data other than the object. The “chaff” data is discarded by the I/O system or file system using, e.g., a bit mask, subsequent to the read.