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:
Oct. 08, 2002
Filed:
Oct. 21, 1999
Ronald Maynard Kern, Tucson, AZ (US);
Gregory Edward McBride, Tucson, AZ (US);
David Michael Shackelford, Tucson, AZ (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A system, method, and program for maintaining data consistency among updates to data storage areas are provided. Each update has an update time the update was made. There are multiple groups of data storage areas. For each group, updates to the data storage area in the group are stored in a journal for storing updates to the group, wherein there are multiple journals. An indication is made in a memory area for each group of a group update time comprising a most recent update time of the updates in the group. The update time for each update in the group is not greater than the group update time. A determination is made of a minimum group update time across all the groups. At least one update is applied to storage if the update time for the update does not exceed the minimum group update time. The data storage areas may be partitioned among a plurality of computer systems, and may be maintained in at least one primary and secondary storage. The data storage areas may also comprise volumes, with each group including at least one volume. The groups of updates may also be maintained in a journal.