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:
Aug. 29, 1995
Filed:
Mar. 23, 1993
Robert W Shomler, Morgan Hill, CA (US);
James E McIlvain, San Jose, CA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and system for asynchronous remote data duplexing at a distant location from copies based at a primary site storage subsystem, which copying is non-disruptive to executing applications, and further in which any data loss occasioned by losses in flight or updates never received at the time of any interruption between the primary and remote sites are accounted for at the remote site. The method assigns a token and unique sequence number responsive to each write operation at the primary site, and sends the tokens+numbers and data updates to the remote site. The method relies upon the sequence number to establish a sequency and define gaps therein to ascertain missing updates.