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:
Dec. 31, 2013
Filed:
Sep. 25, 2012
Emc Corporation, Hopkinton, MA (US);
Sairam Veeraswamy, South Grafton, MA (US);
Peter C. Bixby, Westborough, MA (US);
Peter W. Madany, Hopkinton, MA (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
To preserve the contiguity of file map extents of a production file when making a series of snapshot copies, the snapshots share indirect blocks of the production file through virtual pointers. When a write to a data block of the production file is first done since the time of the most recent snapshot so that the most recent snapshot can no longer share one of the contiguous indirect blocks, a new indirect block is allocated to store the file mapping metadata for the most recent snapshot, and a virtual pointer for the snapshots is changed to point to this new indirect block. Therefore the change in the virtual pointer changes the file mapping metadata for any number of snapshots sharing the new indirect block so that the method is scalable.