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:
Aug. 04, 2020
Filed:
Oct. 31, 2018
Emc Ip Holding Company Llc, Hopkinton, MA (US);
Kumari Bijayalaxmi Nanda, Edison, NJ (US);
Alexander S. Mathews, Morganville, NJ (US);
Soumyadeep Sen, Highland Park, NJ (US);
Michal Marko, Fanwood, NJ (US);
EMC IP Holding Company LLC, Hopkinton, MA (US);
Abstract
Techniques for tracking pages that are unshared among snapshot volumes and their parent volume in a volume family. The techniques include maintaining a first counter that tracks a first number ('SnapOwnedCount') of pages among a total number of pages written to a volume that were overwritten in the immediate sequential next volume in the same branch as the volume, and a second counter that tracks a second number ('UnsharedWithParentCount') of pages among the total number of pages written to the volume that were overwritten in any sequential next volume in the same branch as the volume. By maintaining, for each volume in a volume family, a first counter and a second counter for tracking the SnapOwnedCount and the UnsharedWithParentCount, respectively, data storage recovery can be performed more effectively, allowing selected volumes and/or portions thereof to be deleted while maintaining accurate space accounting information.