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:
Apr. 26, 2011
Filed:
May. 15, 2008
Peter F. Corbett, Lexington, MA (US);
Christopher Wagner, Langley, WA (US);
Peter F. Corbett, Lexington, MA (US);
Christopher Wagner, Langley, WA (US);
NetApp, Inc., Sunnyvale, CA (US);
Abstract
A lightweight coherency control protocol ensures consistency of data containers, such as a file, and associated data buffers stored on one or more volumes served by a plurality of nodes, e.g., storage systems, connected as a cluster. Each data buffer is associated with a current cache sequence number comprising a load generation value and an update count value. The load generation value is incremented every time an inode of a file is loaded into a memory of the storage system. Once the inode is loaded and its load generation value is set, then the appropriate buffer of a buffer tree for the file is loaded into the memory. The update count value is incremented each time the buffer is updated with a write request/operation. Therefore, each buffer loaded into memory is tagged with the load generation value and an update count from the time that buffer is loaded.