Ubuntu 18.04 server crashed after installing nvidia-driver-435

I installed nvidia-driver-435 on an Ubuntu 18.04 server with 8 pieces of 1080ti(using my own notebook win10 by MobaXterm)(without uninstall the old version(I am not sure if there is one)
During the procession, there happen to come out a little warning or error while I did not care.
Then I tapped a command

nvidia-smi

and then it get stuck. I tapped ctrl+C but the command didn’t stop. Then I closed the window.
Soon I try to reconnect the server but it never
works which showed that the “Ping” is well connected but a connection error occurs(timeout). It seems like crashed. But what is extremely hard is that the workers have been in holiday so it’s impossible to reboot the server in hardware’s way.
So, what can I do?