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. 20, 1994
Filed:
Oct. 18, 1990
Applicant:
Inventors:
Jaishankar M Menon, San Jose, CA (US);
James M Kasson, Menlo Park, CA (US);
Assignee:
IBM Corporation (International Business Machines Corporation), Armonk, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03M / ;
U.S. Cl.
CPC ...
371 401 ; 395575 ;
Abstract
A method for update writing in an array of DASDs in a reduced number of DASD track cycles. The method involves distributing data and parity blocks for each parity group across the array in failure independent form and reserving unused space. During a first cycle, the old data and parity blocks are read. The new parity is calculated and shadow written into reserved unused space located before the old parity block recurs. The amended data is either written in place during a second cycle or shadow written into reserved space during a subsequent portion of the first cycle.