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:
Sep. 02, 2008
Filed:
Oct. 21, 2005
Keiichi Kaiya, Hadano, JP;
Katsuhiro Okumoto, Odawara, JP;
Shuji Kondou, Odawara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A storage system secures system redundancy through a simple configuration. A primary storage control device and first secondary storage control device are connected by a synchronous method, and the primary storage control device and a second secondary storage control device are connected by an asynchronous method. The primary storage control device sets control numbers for update data, and saves journal data. The primary storage control device transmits the update data to the first secondary storage control device. The first secondary storage control device writes update data to a first secondary volume, and uses a plurality of bitmap tables to manage differences. If the primary storage control device stops operation, the first secondary storage control device becomes the new primary storage control device. Differential copying is performed from the first secondary storage control device to the second secondary storage control device.