A disk array for a storage system that includes a dual controller disk array and a server includes a disk frame and two controller nodes. Each controller node includes a switch, where a port of the switch is connected to a port of a switch of a peer controller node. Each controller node is configured to detect whether the peer controller node is invalid through the port. When it has been detected that the peer controller node is invalid, a local controller node enables the peer controller node to send, through the port of the switch of the peer controller node, received data from the server to a port of a switch of the local controller node.