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:
Feb. 19, 2013
Filed:
Mar. 14, 2005
John J Wolfgang, Winston-Salem, NC (US);
Kenneth F Day, Iii, Tucson, AZ (US);
Philip M Doatmas, Tucson, AZ (US);
Henry E Butterworth, Eastleigh, GB;
Carlos F Fuente, Portsmouth, GB;
John J Wolfgang, Winston-Salem, NC (US);
Kenneth F Day, III, Tucson, AZ (US);
Philip M Doatmas, Tucson, AZ (US);
Henry E Butterworth, Eastleigh, GB;
Carlos F Fuente, Portsmouth, GB;
International Business Machines Corporation, Armonk, NY (US);
Abstract
Methods and apparatus are provided for copying data from a primary storage facility to a secondary storage facility which reduce the workload on the storage controller in the primary facility and minimize bandwidth usage. The primary storage facility includes a primary data replication appliance which transfers data to a secondary replication appliance. Updated data from a host is both stored through a storage controller in the primary facility and also received by the primary replication appliance. Logic in the primary replication appliance determines whether the immediately previous version of the data is in a buffer from a previous storage operation. If so, the current (updated) version of the data is compared with the previous version and the difference, such as calculated through a bit-wise exclusive-OR operation, is transferred to the secondary replication appliance. The process is reversed in the secondary replication appliance and the recreated updated version of the data stored in the secondary facility.