The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 16, 2010
Filed:
Oct. 14, 2003
Norbert P. Kusters, Woodinville, WA (US);
Benjamin A. Leis, Seattle, WA (US);
Mark J. Zbikowski, Woodinville, WA (US);
Norbert P. Kusters, Woodinville, WA (US);
Benjamin A. Leis, Seattle, WA (US);
Mark J. Zbikowski, Woodinville, WA (US);
Microsoft Corporation, Redmond, WA (US);
Abstract
A differential snapshot is established and maintained for a set of files stored on a volume. Copy-on-write operations are avoided for logically insignificant moves of blocks, such as the block rearrangements characteristic of defragmentation utilities. A file system passes a block copy command to lower-level drivers that are to inform the snapshotter that a block move operation is not logically meaningful. When the logically insignificant move is of a block whose data forms part of the data captured in the snapshot virtual volume, and when the move is to a block location that is functioning as logical free space, the snapshotter can simply modify its block bitmap and update translation table entries without needing to perform a copy-on-write.