Patent ID: 7847801
Filing Date: 2010-12-07
Classification: G06F

Abstract:
1. A computer implemented method for managing a dual active controller array that includes a first controller and a second controller, the computer implemented method comprising: receiving, by the first controller from an operating system, an inquiry that includes a specific logical unit number that identifies a particular one of a plurality of logical units; responsive to receiving the inquiry, determining, by the first controller, whether the first controller is a preferred controller for the particular one of the plurality of logical units; responsive to receipt of the inquiry and to the first controller determining that the first controller is the preferred controller for the particular one of the plurality of logical units: returning, by the first controller, a first peripheral qualifier to the operating system that indicates that the first controller is the preferred controller for the particular one of the plurality of logical units; and responsive to receipt of the inquiry and to the first controller determining that the first controller is not the preferred controller for the particular one of the plurality of logical units: returning, by the first controller, a second peripheral qualifier to the operating system that indicates that the second controller is not the preferred controller for the particular one of the plurality of logical units.