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:
Oct. 25, 2011
Filed:
Jan. 14, 2008
Shunji Kawamura, Yokohama, JP;
Hisao Homma, Odawara, JP;
Shunji Kawamura, Yokohama, JP;
Hisao Homma, Odawara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In the storage controller of the present invention, different difference bitmaps are used for predetermined sections respectively, whereby the difference between the primary volume and the base volume is managed for each section, and the data are protected efficiently. The difference between the primary volume and the base volume is managed by using the difference bitmaps that are different for the respective sections. The journal data after a lapse of the targeted protection period are written to the base volume and then discarded. At the time of recovery, the difference bitmaps are merged to create a new difference bitmap, and the difference is copied from the base volume to the primary volume. Thereafter, the journal data up to the designated restoration point are written to the primary volume.