I've spent hours working on the "NVIDIA-SMI has failed because it couldn’t communicate with the NVIDIA driver. Make sure that the latest NVIDIA driver is installed and running" error. This worked for me (yes it is an output from an LLM), I hope this works for someone else and I am by no mean trying to step on the developer (you can remove this if you see it fit), it's just hard to read through 216 pages of issues. Issue After installing an NVIDIA GPU (RTX 3060 / 5070 Ti) in Unraid, nvidia-smi failed with: NVIDIA-SMI has failed because it couldn't communicate with the NVIDIA driver
dmesg showed that the nouveau driver was binding to the GPU during early boot: nouveau 0000:xx:xx.x: NVIDIA GA106
NVRM: No NVIDIA devices probed
This caused the NVIDIA kernel module to load but find no devices, resulting in modprobe: No such device. Root CauseUnraid was loading the nouveau driver at boot before the NVIDIA driver, even though the NVIDIA plugin was installed. Blacklisting nouveau via modprobe.d alone was not sufficient, because nouveau was loaded during early kernel initialization. FixDisable nouveau at the kernel boot level using Syslinux: Go to Main → Flash → Syslinux Configuration Under Unraid OS, modify the append line: Before: append initrd=/bzroot
After: append modprobe.blacklist=nouveau nouveau.modeset=0 initrd=/bzroot
Apply changes and reboot. After reboot: lsmod | grep nouveau → no output lspci -nnk shows Kernel driver in use: nvidia nvidia-smi works correctly ResultGPU is properly claimed by the NVIDIA driver, CUDA is available, and both proprietary and open-source NVIDIA drivers work as expected (confirmed with RTX 5070 Ti on Open Source driver).