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:
Nov. 03, 2015
Filed:
Jan. 24, 2013
Fujitsu Limited, Kawasaki-shi, Kanagawa, JP;
Takashi Murayama, Nagano, JP;
Fumio Matsuo, Nagano, JP;
Katsuo Enohara, Kawaguchi, JP;
Takaaki Yamato, Nagano, JP;
Nobuyuki Hirashima, Nagano, JP;
Tetsuya Kinoshita, Nagano, JP;
FUJITSU LIMITED, Kawasaki, JP;
Abstract
A virtual tape device includes a storage unit, a cache determining unit, a selector, and a cache controller. The storage unit records logical volume information associated with an identifier of a logical volume, an updated time of the logical volume, information indicating whether the logical volume is allocated to a cache, an identifier of a physical volume storing data of the logical volume, and information indicating whether the physical volume are mounted in a physical tape drive. The cache determining unit determines, based on the logical volume information, whether the logical volume exists on the cache, when a request to store the logical volume on the cache is received and the cache does not have an available capacity. The selector selects the logical volume based on the determined result as an off-cache target logical volume. The selected logical volume is off-cached by the cache controller.