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:
Apr. 12, 2016
Filed:
Mar. 25, 2011
Hiroaki Akutsu, Yokohama, JP;
Yoshinori Ohira, Yokohama, JP;
Yoshiaki Eguchi, Yokohama, JP;
Masayuki Yamamoto, Sagamihara, JP;
Hiroaki Akutsu, Yokohama, JP;
Yoshinori Ohira, Yokohama, JP;
Yoshiaki Eguchi, Yokohama, JP;
Masayuki Yamamoto, Sagamihara, JP;
HITACHI, LTD., Tokyo, JP;
Abstract
If a monitor measurement cycle is set as a long cycle, promotion in a short cycle cannot be performed; and even if the number of I/Os is very large in response to fluctuations of the number of I/Os in several minutes to several hours of normal work, pages will be promoted after waiting for several weeks. As a result, I/Os which could have normally accepted by an upper tier will be accepted by a lower tier, which results in a problem of worsening the performance efficiency. A monitoring system capable of preventing demotion due to temporary reduction of the number of I/Os for specific pages from a viewpoint of a long cycle and enabling prompt promotion in response to an increase of the number of U/Os for 3 the specific pages is realized. A load index value defined from a viewpoint of a long cycle and a load index value defined from a viewpoint of a short cycle are updated based on the number of I/Os which is counted cyclically for each storage area. Promotion and demotion are implemented based on a value(s) calculated from these load index values.