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:
May. 20, 2014
Filed:
Nov. 25, 2011
Saeko Yoshida, Odawara, JP;
Kosuke Sakai, Isehara, JP;
Koji Nagata, Kaisei, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A storage apparatus obtains a snapshot(s) of a first logical volume when needed and saves old data to a second logical volume when data is written to the first logical volume after obtaining the snapshot. A storage area of the second logical volume is allocated in chunk units to the first logical volume and a tendency of order to delete snapshots is judged when the chunks have been completely used up. If there is a tendency to delete the snapshots in their acquisition order, a new chunk is allocated to the first logical volume and a storage area in that chunk is determined to be a save location of the old data. If there is a tendency to delete the snapshots randomly, an unused storage area in a chunk already allocated to the first logical volume is determined to be the save location of the old data.