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:
Dec. 01, 2009
Filed:
Feb. 02, 2007
Shoji Sugino, Odawara, JP;
Yoshinori Igarashi, Odawara, JP;
Eiju Katsuragi, Odawara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The expansion of a mapping table with additional mapping information involved in the access to virtual volumes is prevented and so a search in the mapping information within a valid time period is ensured, thereby preventing degradation of system performance. A storage apparatus, which defines virtual volumes to which storage areas are dynamically allocated, has a data migration function to migrate data between the virtual volumes and real volumes. With the data migration function, the mapping information for the migrated data is deleted from the mapping table, and accordingly, the size of the mapping table can be limited.