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. 05, 2008
Filed:
Apr. 27, 2005
Yuanru Frank Wang, Broomfield, CO (US);
Paul Andrew Ashmore, Longmont, CO (US);
Yuanru Frank Wang, Broomfield, CO (US);
Paul Andrew Ashmore, Longmont, CO (US);
Abstract
A data storage system configured for efficient operation in a single controller mode and to facilitate an upgrade from single controller operation to dual redundant active-active controller operation is provided. More particularly, a first controller having a segmented write cache is provided. The first segment of the write cache is associated with logical unit numbers (LUNs) owned by the first controller. The second segment is associated with LUNs that are designated as being owned by a second controller. During single controller operation, the segments of the write cache operate as primary write cache. The system may be converted to dual redundant controller operation by adding a second controller having a write cache segmented like the write cache of the first controller. Upon adding a second controller, primary control of the LUNs owned by or zoned to the second controller is taken over by the second controller.