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:
Jun. 01, 2010
Filed:
Oct. 25, 2004
Ashish Prakash, Morrisville, NC (US);
John K. Edwards, Sunnyvale, CA (US);
Sriram Rao, San Jose, CA (US);
Ashish Prakash, Morrisville, NC (US);
John K. Edwards, Sunnyvale, CA (US);
Sriram Rao, San Jose, CA (US);
NetApp, Inc., Sunnyvale, CA (US);
Abstract
A multi-stage technique invalidates and replaces loadable physical volume block numbers (pvbns) stored in indirect blocks of a dual vbn ('flexible') virtual volume (vvol) of a storage system to enable efficient image transfers and/or fragmentation handling of the flexible vvol. Each loadable pvbn of a pvbn/virtual vbn (vvbn) block pointer pair is converted into a special block pointer having a predefined reserved value that provides a temporary 'pvbn_unknown' placeholder until replaced by a real (actual) pvbn. The technique further allows the storage system to serve data from the flexible vvol using the placeholders while the actual pvbns are computed, thereby eliminating latencies associated with completion of actual pvbn replacement for the pvbn_unknown placeholders.