The Error Encountered

If you are a non-root user and you issue a command, you might see the error

% nvidia-smi
NVML: Insufficient Permissions" error

The default module option NVreg_DeviceFileMode=0660 set via /etc/modprobe.d/nvidia-default.conf. This causes the nvidia device nodes to have 660 permission.

vim /etc/modprobe.d/nvidia-default.conf

options nvidia NVreg_DeviceFileUID=0 NVreg_DeviceFileGID=1001 NVreg_DeviceFileMode=0660

The Fix

[user1@node1 dev]$ ls -l nvidia*
crw-rw---- 1 root vglusers 195,   0 Jan  5 17:07 nvidia0
crw-rw---- 1 root vglusers 195, 255 Jan  5 17:07 nvidiactl
crw-rw---- 1 root vglusers 195, 254 Jan  5 17:07 nvidia-modeset

The reason for the error is due to the vglusers or video group. The fix is simply putting the users in the /etc/group

# usermod -a -G vglusers user1 

Logged off and Login again, you should be able to do nvidia-smi

References:

A fix for the “NVML: Insufficient Permissions”