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:
Apr. 07, 1998
Filed:
Mar. 22, 1996
Albert Stephen Hilditch, Stockport, GB;
International Computers Limited, Putney, GB;
Abstract
Each node of a distributed (multi-node) data processing system, which includes a plurality of shared data storage disks, has a respective incremental backup bit-file containing one bit for each datablock of the shared disks. The bits are initially set to logical 0. When a node writes data to a datablock the respective bit is reset to logical 1. Upon an incremental backup requirement, one node reads all of the bit-files, forms the logical OR thereof and forms a respective new bit-file. The blocks whose bits equal 1 in this new bit-file are then backed up. The bit-files are stored in the node main memories for quick access and will be lost upon node failure. However if a redo log is maintained, bit-files can be reconstructed.