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:
Jul. 04, 2017
Filed:
Mar. 31, 2015
Emc Corporation, Hopkinton, MA (US);
Vamsi Vankamamidi, Shrewsbury, MA (US);
David W. Harvey, Newton, MA (US);
EMC IP Holding Company LLC, Hopkinton, MA (US);
Abstract
A technique for managing file systems that support block sharing places a source/copy attribute in each block pointer. The source/copy attribute identifies the respective block pointer as either a source-block pointer or a copy-block pointer. A reference count on each data block maintains a count of the number of source-block pointers pointing to the data block but excludes the number of copy-block pointers pointing to the data block. Block pointers are arranged in block pointer sets (BPSs), and sharing relationships are formed among BPSs and copies of BPSs. The sharing relationships generally keep most block sharing information at the BPS level, with reference counts on data blocks tracking only the number of source-block pointers, which is typically small, often being equal to one.