An Unresponsive status indicates that one controller or both controllers in a storage subsystem cannot be reached by the storage management station. An Unresponsive status is represented by this icon in the Device Tree or Device Table Views.
If the storage subsystem has an operational controller, you can launch the Subsystem Management Window, but all management operations that require communication with the unresponsive controller will fail. If both controllers are unresponsive, you will receive error notices if you attempt to launch the Subsystem Management Window.