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. 21, 2012
Filed:
Sep. 30, 2008
Hongliang Tang, Shrewsbury, MA (US);
Sairam Veeraswamy, South Grafton, MA (US);
Peter Bixby, Westborough, MA (US);
Hongliang Tang, Shrewsbury, MA (US);
Sairam Veeraswamy, South Grafton, MA (US);
Peter Bixby, Westborough, MA (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
Embodiments of the invention relate to maintaining reference counts in a file system to track when a block is available to be freed. When a snapshot copy of a file is created, rather than copying all the blocks of the file for the snapshot copy, the snapshot inode is given pointers to the blocks of the file. Rather than updating the reference counts for all these blocks to indicate that they are now in use by more than one file, the update of reference counts for at least some of these blocks may be deferred until a later time.