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. 06, 2010
Filed:
Jan. 21, 2005
Naoki Soeda, Tokyo, JP;
Naoki Soeda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Provided is a data storing system which holds only updated data by a snapshot action of a disk array subsystem. When there is generated a writing request to snapshot duplicate volumes as the duplicate data storing areas, unused pages for the requested amount is searched from a common logical-volume which is used in common as a real data storage area within the disk array subsystem, and address conversion of the page is performed. The result of the address conversion is held in a directory which is provided for each of the snapshot duplicate volumes. When making an access to the page thereinafter, the directory is always being referred to, and the address conversion is performed from the page of the snapshot duplicate volumes to the corresponding page of the common logical-volume.