US 7,720,819 B2 May 18, 2010
(54) METHOD AND APPARATUS COMBINING
REVISION BASED AND TIME BASED FILE
(75) Inventors: Christopher Victor Lazzaro, Austin,
TX (US); Thomas Edward O'Brien,
Round Rock, TX (US); Borna
Safabakhsh, Austin, TX (US)
(73) Assignee: International Business Machines
Corporation, Armonk, NY (US)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 373 days.
(21) Appl.No.: 11/734,359
(22) Filed: Apr. 12, 2007
A method and apparatus for protecting file data is provided that combines or merges revision based backup with backup based on time intervals. One embodiment is directed to a method for protecting data contained in a file of a computer system, wherein the computer system is useable to create multiple successive file versions. The method comprises the steps of specifying a maximum number of file versions that can be stored collectively at first and second storage locations, and apportioning the maximum number into a first number of file versions and a second number of file versions. The method further comprises storing the most recent of the multiple file versions, up to a number equal to the first number, at the first storage location. A number of file versions respectively created before the stored most recent versions, up to a number equal to the second number, are stored at the second storage location, over a pre-specified time period and in accordance with a pre-specified strategy.
19 Claims, 3 Drawing Sheets