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:
Mar. 04, 2008
Filed:
Mar. 06, 2002
Robert A. Cochran, Rocklin, CA (US);
Robert A. Cochran, Rocklin, CA (US);
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Abstract
On a dominant logical unit provided by a mass-storage device, hot spare disks are employed to create a much larger, disk-based time-ordered WRITE-request buffer that spans, in one embodiment, both electronic memory and hot spare disks. The much larger time-ordered WRITE-request buffer in the modified dominant logical unit allows for storing WRITE requests in time order for a much longer period of time during communications failure between the dominant logical unit and remote-mirror logical unit than in the current techniques that employ only an electronic-memory-based time-ordered WRITE-request buffer. On the remote-mirror logical unit, mass-storage space is provided for an alternate logical unit that can be resynchronized with the dominant logical unit following restoration of communications between the dominant logical unit and remote-mirror logical unit. When resynchronization is complete, a simple logical-unit-pointer switch operation can be employed to designate the alternate logical unit as the new remote-mirror logical unit, and the previous remote-mirror logical unit as the alternate logical unit.