Techniques involve: acquiring, through a first downstream port of a first switch of a data storage system, information indicating an error of a storage device array from a second switch of the data storage system, wherein the first switch and the second switch are connected to the storage device array and the first downstream port is connected to a second downstream port of the second switch; executing, based on the acquired information, actual actions intended for solving the error; and in response to the executed actual actions failing to match with expected actions for the error, issuing an alarm indicating failure of processing the error.