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. 23, 1993
Filed:
Aug. 03, 1990
Applicant:
Inventors:
Richard L Mattson, San Jose, CA (US);
Spencer Ng, San Jose, CA (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
371 111 ; 395725 ; 395425 ; 371401 ; 371 102 ;
Abstract
A method and apparatus are disclosed which minimize the additional read and write loading for each remaining DASD in a DASD array occasioned by a single point of failure where subsets of DASDs may accessed asynchronously (RAID 4 or RAID 5). In this method, parity groups are written across the array in a pattern forming a balanced incomplete block design or the equivalent. In the event of failure of a DASD in the array, then any additional loading resulting from the failure is uniformly spread among the remaining DASDs.