Abstract: One aspect of the present invention provides an operation for recovering lost space and maintaining data consistency in a storage environment by providing a two-way orphan reconciliation method for extremely large file systems, such as a Hierarchical Storage Management (HSM) system which manages billions of files. This highly scalable and parallelizable orphan identification process may be used in a HSM controlled environment to enable the execution of a two-way file orphan check. In one embodiment, this orphan check identifies file system client orphans and server object orphans in a single pass by comparing a queue containing a list of migrated files on a storage repository server with a queue containing a list of stub files on a file system. If the queue elements do not match, a file system orphan or server object orphan can appropriately be identified.

Abstract: Performing a backup of a stub object located on a file system managed by a hierarchical storage manager configured to migrate data objects from the file system to a migration storage pool. The stub object includes information for recalling a migrated data object and is configured to determine whether a backup copy of the migrated data object is stored in a backup storage pool if the backup is performed in an incremental backup operation. The backup further includes directing the hierarchical storage manager to recall the migrated data object to the file system if the backup copy of the migrated data object is not stored in the backup storage pool or if the backup is performed in a selective backup operation. The backup additionally includes storing a backup copy of the migrated data object in the backup storage pool if the migrated data object is recalled.

Abstract: Performing a backup of a stub object located on a file system managed by a hierarchical storage manager configured to migrate data objects from the file system to a migration storage pool. The stub object includes information for recalling a migrated data object and is configured to determine whether a backup copy of the migrated data object is stored in a backup storage pool if the backup is performed in an incremental backup operation. The backup further includes directing the hierarchical storage manager to recall the migrated data object to the file system if the backup copy of the migrated data object is not stored in the backup storage pool or if the backup is performed in a selective backup operation. The backup additionally includes storing a backup copy of the migrated data object in the backup storage pool if the migrated data object is recalled.

Abstract: A method for performing backup of a stub object located on a file system managed by a hierarchical storage manager configured to migrate data objects from the file system 10 a migration storage pool includes determining whether a backup copy of the migrated data object is stored in a backup storage pool if the backup is performed in an incremental backup operation. The storage manager recalls the migrated data object to the file system if the backup copy of the migrated data object is not stored in the backup storage pool or if the backup is performed in a selective backup operation. If the migrated data object is recalled, the backup copy of the migrated data object is created and stored in the backup storage pool. If the migrated data object is not recalled, a backup copy of the stub object is created and stored in the backup storage pool.

Abstract: A method of synchronous deletion of managed files in a file system includes receiving a destroy event for a file to be deleted from the file system, the destroy event being generated upon request to destroy a file or corresponding objects of the files system; processing the received destroy event. Processing the destroy event includes determining if hierarchical storage management of the file system is initiated, and if initiated, continuing processing of the received destroy event; blocking threads indefinitely for an event storm during processing of the received destroy event; determining if the file to be deleted is being premigrated, migrated or is being recalled; aborting migration of the file based on the determination of migration and recall; and deleting the file and server objects corresponding to the file from the file system, where initiation of file deletion and server object deletion are synchronous.

Abstract: One aspect of the present invention provides an operation for recovering lost space and maintaining data consistency in a storage environment by providing a two-way orphan reconciliation method for extremely large file systems, such as a Hierarchical Storage Management (HSM) system which manages billions of files. This highly scalable and parallelizable orphan identification process may be used in a HSM controlled environment to enable the execution of a two-way file orphan check. In one embodiment, this orphan check identifies file system client orphans and server object orphans in a single pass by comparing a queue containing a list of migrated files on a storage repository server with a queue containing a list of stub files on a file system. If the queue elements do not match, a file system orphan or server object orphan can appropriately be identified.

Abstract: A method for performing a backup of a stub object located on a file system managed by a hierarchical storage manager configured to migrate data objects from the file system to a migration storage pool is provided. The stub object includes information for recalling a migrated data object.

Abstract: An example of a method for assigning storage includes receiving a request for storage, wherein the request includes a requested amount of storage space and connectivity information. This example of the method also includes identifying storage that is accessible by a requesting device based on the connectivity information, and identifying all LUNs that are masked from all hosts, in the identified storage. This example of the method further includes selecting at least one identified LUN, and assigning the at least one selected LUN to the requesting device.