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:
Jun. 10, 2003
Filed:
Jun. 24, 1997
Robert Nelson Crockett, Tucson, AZ (US);
William Frank Micka, Tucson, AZ (US);
Robert Wesley Shomler, Morgan Hill, CA (US);
Warren Keith Stanley, Tucson, AZ (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for assuring consistency between a primary volume and a remote secondary volume wherein a host CPU manages track-to-track transfers using loosely-coupled, storage control unit mediated data paths. The method includes initial volume synchronization in which concurrent updates to primary tracks are serialized by the copy progression at the secondary volume according to address. The method further includes volume resynchronization in the event of extrinsic error, fault, or the like in which bit maps and timestamps are used to determine the status of primary tracks either lost while in flight to the secondary volume or updated during a volume suspension interval. The bit maps and timestamps preserve the most recent version copy order of the tracks on the secondary volume. CONCURRENT UPDATING