Patent ID: 7779170

Claim:
A method for determining a data path in a storage network, the network having a path processor for directing data onto one of two or more paths between an application host and two or more storage controllers in a storage subsystem, the method comprising: monitoring the operational status of a storage controller in the storage subsystem, by a first controller monitor; determining whether a change in the operational status of the storage controller is a failure or a potential failure; and, sending the determination to the path processor, wherein the path processor redirects application host data from a path controller on the basis of the determination, wherein the storage controller is a first storage controller of the two or more storage controllers, and the two or more storage controllers further comprise a second storage controller, wherein the method further comprises: monitoring the operational status of the first storage controller by the second controller monitor directly reading the first storage controller; monitoring the operational status of the second storage controller by the first controller monitor directly reading the second storage controller; monitoring the operational status of the second storage controller by the second controller monitor directly reading the second storage controller, wherein if the first controller monitor does not send an operational status message regarding the first storage controller, then the second controller monitor sends the operational status message regarding the first storage controller.