Abstract: Mechanisms are provided for importing pre-existing data into a storage system utilizing a current storage management system that is different from an original storage management system used to create the pre-existing data. One or more data storage devices are integrated into the storage system in-place without modification of the pre-existing data stored on the one or more data storage devices. Metadata for the pre-existing data is created based on a linear progression of data in the pre-existing data. Read access requests targeting the pre-existing data are executed using the created metadata. Write access requests targeting the pre-existing data are executed by redirecting the write access requests to a copy of the pre-existing data created in another storage location.

Abstract: Mechanisms are provided for importing pre-existing data into a storage system utilizing a current storage management system that is different from an original storage management system used to create the pre-existing data. One or more data storage devices are integrated into the storage system in-place without modification of the pre-existing data stored on the one or more data storage devices. Metadata for the pre-existing data is created based on a linear progression of data in the pre-existing data. Read access requests targeting the pre-existing data are executed using the created metadata. Write access requests targeting the pre-existing data are executed by redirecting the write access requests to a copy of the pre-existing data created in another storage location.

Abstract: A method for performing stripe placement within a storage system is disclosed. After a set of failure domains within a storage system has been identified, the failure domains are then organized to form a hierarchy of failure domains. A failure domain is defined as a group of one or more disks that are more likely to fail together because a common component is shared by that group of disks. Stripe placement is performed across all active failure domains within the storage system using a greedy algorithm.

Abstract: A method for performing stripe placement within a storage system is disclosed. After a set of failure domains within a storage system has been identified, the failure domains are then organized to form a hierarchy of failure domains. A failure domain is defined as a group of one or more disks that are more likely to fail together because a common component is shared by that group of disks. Stripe placement is performed across all active failure domains within the storage system using a greedy algorithm.

Abstract: A computer-implemented method of managing lease transactions from a plurality of time-synchronized cluster nodes for a shared leased resource in a computer network, the method including accepting, during a request period, requests to lease a shared leased resource in an upcoming lease interval, the requests received from among a plurality of time-synchronized cluster nodes. The method may include selecting, during a response period which concludes prior to the beginning of the upcoming lease interval, a leaseholder for the shared leased resource in the upcoming lease interval in response to receiving at least one request during the request period, the leaseholder selected based on the at least one received request. The response period may occur after the request period. The method may include notifying, during the response period, the selected leaseholder of its selection as the leaseholder for the shared leased resource in the upcoming lease interval.

Abstract: A method, system and computer-usable medium are disclosed for tracking blocks moved within a file system, comprising: associating tracking information with a base object within the file system; tracking movement of the base object via the tracking information; and, adjusting information relating to an associated object of the base object derived from the base object.

Abstract: A method includes determining, by a processor, that a write request indicates a clone file that was cloned from a file in a first fileset. The clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset. A data block of the clone file affected by the write request is determined. The method includes determining that the data block at a current location cannot be modified. In response to a determination that the data block at the current location cannot be modified, the method includes implementing the write request with respect to the data block at a different location and indicating that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

Abstract: Various systems, processes, products, and techniques may be used to manage legacy data. In one general implementation, a system, process, and/or product for managing legacy data may include the ability to determine whether a data request has been received and, if a data request has been received, determine whether the data request is associated with legacy data of an external storage management system. If the data request is not associated with legacy data of an external storage management system, the system, process, and/or product may retrieve data from a local storage array, and if the data request is associated with legacy data of an external storage management system, the system, process, and/or product may request legacy data from an external storage management system. The system, process, and/or product may also generate a response to the data request.

Abstract: A method includes determining, by a processor, that a write request indicates a clone file that was cloned from a file in a first fileset. The clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset. A data block of the clone file affected by the write request is determined. The method includes determining that the data block at a current location cannot be modified. In response to a determination that the data block at the current location cannot be modified, the method includes implementing the write request with respect to the data block at a different location and indicating that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

Abstract: According to one aspect of the present disclosure, a method and technique for hierarchical network failure handling in a clustered node environment is disclosed. The method includes: detecting a network failure by a node in a cluster, the cluster having plural nodes arranged in a hierarchy, wherein the network failure is associated with a subordinate node in the hierarchy to the detecting node; communicating the network failure from the detecting node to a superior node in the hierarchy; determining whether the network failure affects nodes higher than the detecting node in the hierarchy; and responsive to determining that the network failure does not affect nodes higher than the detecting node in the hierarchy, the detecting node initiating a protocol to expel the subordinate node from the cluster.

Abstract: Accurate recovery of a primary server at a recovery server is accomplished with reduced network overhead by maintaining at the recovery server checkpoints taken over time of the primary server and an intention log of logical transactions pending and complete by the primary server. The recovery server is brought to the operational state of the primary server as of failure at the primary server by recovering the most recent checkpoint and then executing the transactions indicated by the intention log as received but not complete as of the time that the checkpoint was taken.

Abstract: Hierarchical recovery of failed computing nodes to operative computing nodes within a cluster of computing nodes is managed by initiating a recovery leader at an operative node that retrieves management information from the operative nodes and applies the management information to recover filesets of a meta-fileset in a hierarchical filesystem. The use of hierarchical filesets throughout the cluster provides more rapid failover by distributing recovery load across computing nodes and supporting recovery of nodes in parallel.

Abstract: After a clone file is created from a file, a write request targeting the clone file can be handled. It is determined that the write request indicates the clone file that was cloned from a file in a first fileset. The clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset. A data block of the clone file affected by the write request is determined. It is then determined that the data block at a current location cannot be modified. The write request is implemented with respect to the data block at a different location. It is indicated that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

Abstract: Embodiments include a computer program product and an apparatus for cloning files across different filesets and maintaining the clone files. After a clone file is created from a file, a write request targeting the clone file can be handled. It is determined that the write request indicates the clone file that was cloned from a file in a first fileset. The clone file is of a second fileset and a clustered file system comprises the first fileset and the second fileset. A data block of the clone file affected by the write request is determined. It is then determined that the data block at a current location cannot be modified. The write request is implemented with respect to the data block at a different location. It is indicated that the data block at the different location can be modified for subsequent write requests that indicate the clone file.

Abstract: A method includes initiating committing to persistent storage of a current consistency snapshot of a plurality of data objects in a redirect-on-write file system. Each of the plurality of data objects has a first copy of at least two copies of the data having a first context of at least two contexts. The method includes receiving, during committing to storage of the current consistency snapshot, an update to a data object of the plurality of data objects. The method also includes responsive to receipt of the update to the data object, creating a second copy of data of the data object from the first copy. The second copy of the data has a second context of the at least two contexts. The method includes responsive to receipt of the update to the data object, updating, based on the update, the second copy of the data of the data object.

Abstract: Management of a file hierarchy for a clustered file system can be distributed across nodes of the cluster. A cluster file hierarchy is accessed to determine location of a file in response to a request to write to a file. A first node maintains the cluster file hierarchy. It is determined that management of a fileset object, which represents a fileset that includes the file, has been delegated to a second node based, at least in part, on said accessing the cluster file hierarchy. A node file hierarchy maintained by the second node is accessed responsive to determining the delegation. The cluster file hierarchy represents filesets of the clustered file system and the node hierarchy represents a subset of one or more of the filesets. Location of the file is determined based, at least in part, on said accessing the node file hierarchy.

Abstract: Management of a file hierarchy for a clustered file system can be distributed across nodes of the cluster. A cluster file hierarchy is accessed to determine location of a file in response to a request to write to a file. A first node maintains the cluster file hierarchy. It is determined that management of a fileset object, which represents a fileset that includes the file, has been delegated to a second node based, at least in part, on said accessing the cluster file hierarchy. A node file hierarchy maintained by the second node is accessed responsive to determining the delegation. The cluster file hierarchy represents filesets of the clustered file system and the node hierarchy represents a subset of one or more of the filesets. Location of the file is determined based, at least in part, on said accessing the node file hierarchy.

Abstract: In a cluster that distributes fileset management, fileset managers will maintain a free block map and an in-flight block map to allocate blocks to clients writing to a relevant fileset. A fileset manager managing free block allocation for cluster clients that write to a fileset managed by the fileset manager. Since a clustered file system manager manages an initial free block map for the cluster (“cluster free block map”), the clustered file system manager provisions free blocks to fileset managers from the cluster free block map. The fileset manager then allocates free blocks from the provisioned free blocks to cluster clients that write to the fileset managed by the fileset manager.

Abstract: Embodiments include a method comprising detecting addition of a new nonvolatile machine-readable medium to a data storage pool of nonvolatile machine-readable media. The method includes preventing from being performed a first operation of a file system that requires a first parameter that identifies a logical indication of a location within the nonvolatile machine-readable media for the file system, until logical indications of locations within the new nonvolatile machine-readable medium for the file system have been stored in the data storage pool. The method includes allowing to be performed, prior to logical indications of locations within the new nonvolatile machine-readable medium being stored in the data storage pool, a second operation of the file system that does not require a second parameter that identifies a logical indication of a location within the nonvolatile machine-readable media, wherein the second operation causes data to be written into the new nonvolatile machine-readable medium.

Abstract: Embodiments include a method for removing a file within a redirect-on-write file system. In some embodiments, a file removal operation is detected in a file management unit, which resides in a memory unit. It is then determined that the number of free data blocks in the persistent storage is below a minimum threshold. The file removal operation is written to a log used for storing system operations. A file management unit is notified of the successful write of the file removal operation to the log used for storing system operations. The data blocks are moved from the file selected for removal to a list of free data blocks. The indirect blocks from the file selected for removal are moved to a data block removal list.