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. 22, 2009
Filed:
Jul. 28, 2006
Takashi Sakaguchi, Odawara, JP;
Sachiko Hoshino, Odawara, JP;
Yasuyuki Nagasoe, Odawara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The present invention carries out cache management in such a manner that the management region required for cache management does not increase, and neither does the performance decline. It is possible to combine use of both a hierarchical directory method and a hash directory method, in order to manage cache data. In a hierarchical directory method, the desired data is retrieved by referring to respective tables Tto T, in succession. In a hash directory method, the desired data is reached by referring to a hash table TIand tables Tto T. Access conflicts between the respective methods are avoided by using the EDEV number and a portion of the VDEV number for a hash key. By combining use of both of these methods, it is possible to respond to cases where the storage capacity of the storage system has been increased, without having to raise the management region, and without causing a decline in performance.