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AssigneeInternational Business Machines Corporation
InventorsDavid Maxwell Cannon, Howard Newton Martin
Estimating the term…
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. Each managed file is reviewed to determine whether it contains any deleted-file space. Managed files without any deleted-file space are simply copied intact to the target storage area. If a managed file contains deleted-file space, however, a "reconstruction" process is performed for that file. Reconstruction identifies any contiguous regions of user files within the managed file, then copies the contiguous regions to adjacent locations in a target storage area. Reclamation is complete after all managed files in the prescribed data storage area have been copied or reconstructed.
A method of reclaiming deleted-file storage space within a managed file originally created with a contiguous aggregation of user files, said deleted-file storage space arising from deletion of individual user files from the managed file, said managed file residing at a source storage area, the method comprising:
A method of reclaiming a source storage area to a target storage area, said source storage area including one or more managed files, each managed file including one or more user files, said method comprising:
A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method for reclaiming deleted-file storage space within a managed file originally created with a contiguous aggregation of user files, said deleted-file storage space arising from deletion of individual user files from the managed file, said managed file residing at a source storage area, said method comprising:
A signal-bearing medium tangibly embodying a program of machine-readable instructions executable by a digital processing apparatus to perform a method for consolidating a unit of stored data from a source location to a target location, said unit including multiple managed files, each managed file including one or more user files, said method comprising:
A data storage subsystem, comprising:
A data storage subsystem, comprising:
Dependencies are inferred from the claim text.