Patent ID: 6880059

Claim:
A system for storing data, comprising: at least one computer; and a disk array apparatus to be used by said at least one computer, said disk array apparatus including: a plurality of disks, a first controller, and a second controller, wherein said first controller has a first exclusive cache and said second controller has a second exclusive cache, and wherein said first controller and said second controller are operatively coupled to said plurality of disks; wherein said first controller controls a plurality of first logical units in said plurality of disks and manages first configuration information of said plurality of first logical units, wherein said second controller controls a plurality of second logical units in said plurality of disks and manages second configuration information of said plurality of second logical units, and wherein said second controller takes over control of a subset of said first logical units including obtaining a portion of said first configuration information associated with said subset of first logical units, wherein said first controller maintains control over those of said first logical units that are not in said subset of first logical units.