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. 02, 1993
Filed:
Jun. 13, 1991
Jaishankar M Menon, San Jose, CA (US);
Richard L Mattson, San Jose, CA (US);
Spencer W Ng, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and means in which data and parity blocks forming parity groups together with spare blocks are distributed over array block locations according to at least one combinatorial design, each group having N data and P parity blocks. The combinatorial designs yield uniform or balanced loading thereby minimizing the number of accesses to reconstruct missing data and parity blocks and their copyback into spare block locations, and, minimize the number of accesses to the reconstructed data referenced subsequent to its copyback. Distributions of the spare block capacity of one or two DASDs are shown over single and multiple arrays and shared among multiple arrays. Parity block distribution although ancillary to spare distribution enhances throughput and reduces the number of accesses for rebuild etc.