Abstract: A data storage subsystem employs managed files, each comprising one or an aggregation of multiple individual, constituent user files, to reduce file management overhead costs. After receiving user files from a client station, the subsystem creates a contiguous managed file by aggregating selected ones of the received user files according to certain predetermined criteria. Managed file creation and use are transparent to the client stations. To aid in file management, the subsystem provides a mapping table that lists, for each user file, a corresponding location of that user file within a managed file. With this hardware and table structure, the system conducts file management with reduced overhead. For example, internal data management operations include an improved copy operation where a managed file is copied as a contiguous unit between first and second locations in the data storage subsystem.

Abstract: A data storage subsystem employs managed files comprising one or a contiguous aggregation of multiple constituent user files. A mapping table cross-references each managed file with the names and locations of its constituent user files. A storage table cross-references each managed file with its address. Eventually, "deleted-file space" arises as individual user files are deleted from managed files. "Reconstruction" consolidates managed files to regain this wasted space. Reconstruction preferably permits multiple embodiments of a managed file called "siblings". Reconstruction identifies contiguous regions of user files within a managed file, and copies these regions to adjacent locations in a target area. Before entering the reconstructed file in any tables, the mapping table is searched for a "paradigm" managed file containing the same user files as the reconstructed file.

Abstract: A data storage subsystem employs managed files, each comprising one or an aggregation of multiple constituent user files, to reduce file management overhead costs. After receiving user files from a client station, the subsystem creates a contiguous managed file by aggregating selected ones of the received user files according to certain predetermined criteria. Managed file creation and use are transparent to the client stations. Eventually, unused or "deleted-file space" arises as individual user files are deleted from their respective managed files. "Reclamation" is triggered when the amount of deleted-file space in a prescribed storage area (e.g. device, volume, managed file, etc.) satisfies certain criteria, e.g. poor data storage efficiency. Reclamation is performed to regain wasted space between managed files, and also space that occurs within managed files due to deletion of some but not all constituent user files. Reclamation is applied to the prescribed storage area one managed file at a time.

Abstract: A data storage subsystem employs managed files comprising one or a contiguous aggregation of multiple constituent user files. A mapping table cross-references each managed file with the names and locations of its constituent user files. A storage table cross-references each managed file with its address. Eventually, "deleted-file space" arises as individual user files are deleted from managed files. "Reconstruction" consolidates managed files to regain this wasted space. Reconstruction preferably permits multiple embodiments of a managed file called "siblings". Reconstruction identifies contiguous regions of user files within a managed file, and copies these regions to adjacent locations in a target area. Before entering the reconstructed file in any tables, the mapping table is searched for a "paradigm" managed file containing the same user files as the reconstructed file.

Abstract: Files are stored along with embedded codes containing information useful in reconstructing a failed database that normally contains information about the files. Multiple user files are stored in the form of a managed file, identified by a managed filename. Storage of the managed file includes a number of sub-steps, among them the generation and storage of a first frame marker including a recognition pattern, the managed filename, a next-frame locator, and a sequence number distinguishing the first frame marker from other frame markers. Next, a self-describing header is generated and stored adjacent to the first frame marker. A first one of the user files is stored adjacent to the self-describing header. The self-describing header and following user file are exclusively associated with each other, and the header contains certain information about the adjacent user file.

Abstract: A data processing system providing disaster recovery and using a client-server configuration provides a method and apparatus for reclaiming off-site storage volumes without requiring the volumes to be mounted or transported to the primary site. The system includes primary volumes and resident copy volumes at the primary site and off-site storage volumes for disaster recovery at the remote site. The system first determines which off-site storage volumes are eligible for reclamation. For each eligible off-site volume, the system locates, within the primary site, a primary copy of every file remaining on the off-site volume that is still required for disaster recovery. These primary copies are then copied to a resident recovery volume at the primary storage site. The eligible off-site volume is then marked empty, and the resident recovery volume is classified as an off-site volume.

Abstract: A data processing system using a storage management server provides a method and apparatus for preserving consistency between a database back-up and a set of storage volumes. The system includes a plurality of client systems coupled to the storage management server. Primary and back-up copies of client files are stored within a set of attached storage volumes. The server contains a server database to maintain directory and reference location information linking the primary and back-up copies of the client files. The server periodically performs an incremental back-up of the server database to a database back-up. The server utilizes a reuse delay criterion to set selected storage volumes as pending volumes. Pending volumes are not eligible for reuse by the server, thereby preventing the server from overwriting these pending volumes and invalidating reference location information for the pending volumes stored in the database back-up.