A Customer's OceanStor V3 Controller B Is Red and the System

A customer's OceanStor V3 controller B is red and the system status indicator is red. The correct way for engineers to deal with this problem is:

A) Log in to the management software or the CLI to check whether the controller is online. If it is not online, restart the controller B on the CLI, and observe the startup status and record Start the abnormal interface and crude without
B) landing management If you press or CLI to check whether the controller is online, if not online, unplug the controller, through the CLI to observe the start-up status, record Kai Abnormal interface and error
C) Serial connection to the controller, COM1 port without printing, can be judged as controller failure, need to be replaced
D) Log in to the management software or CLI to check whether the controller is online, if it is not online, execute restsys, restart the current controller, and observe through the CLI Dynamic state, recording abnormal interface and error