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. 10, 2005
Filed:
Aug. 16, 2002
Naohisa Kasako, Odawara, JP;
Shigeru Kishiro, Odawara, JP;
Takahiko Takeda, Minamiashigara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A technique is described to enable exclusive control on a file basis in a storage system while remote double recording is performed between storage controllers. A first shared-file controller has a table that stores control information used for excluding read and write to that file on a file basis. When the shared-file controller receives a data write request, it sets access to the file as exclusive, and then issues a command to a second shared file controller to set control information for that file. After data is written into a storage medium and mirrored to a second storage medium, a copy of the file management information is stored in memories of the shared-file controllers. The consistency of the file management information is maintained between the two file controllers by copying the file management information over the network.