Originally nvidia-smi was normal, after restarting the server ubuntu system, using nvidia-smi to report an error display:
NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running.
The cause of the error: the kernel version of ubuntu is too high and does not match the graphics card driver. Because the graphics card driver was installed when the kernel version was low.
The solution at this time is to switch back to the lower version of the kernel. How to switch the kernel version of ubuntu?
To switch the kernel tutorial, click https://blog.csdn.net/Thanours/article/details/104834536