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:
Jul. 16, 1996
Filed:
Mar. 14, 1994
Robert E Galbraith, Rochester, MN (US);
Joseph T Writz, Rochester, MN (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
In a redundant array of disk storage units which independently accesses data blocks on different units and which uses parity blocks for data protection, parity blocks are confined to specific address ranges of each respective disk unit (rows of the array), each row containing multiple parity blocks. Each parity block represents the exclusive-OR of a stripe of data blocks located on a diagonal of the array. Where data accesses exhibit locality of reference in certain rows, this arrangement distributes the burden of updating parity more equally than a conventional RAID level 5. Additionally, because a 'row' corresponds to a particular annular region of a disk surface on each respective disk unit, parity blocks can be located at optimal logical addresses or physical regions of the disk surface to simplify address translation and/or further improve performance.