NVIDIA: could not open the device file /dev/nvidia0 (Input/output error).

Linux: CENTOS 5.4
CUDA: 2.3
driver: 190.18…

I have two cards: Geforce8400
295GTX

PCI bus:
02:00.0 PCI bridge: nVidia Corporation PCI express bridge for GTX 295 (rev a3)
03:00.0 PCI bridge: nVidia Corporation PCI express bridge for GTX 295 (rev a3)
03:02.0 PCI bridge: nVidia Corporation PCI express bridge for GTX 295 (rev a3)
04:00.0 3D controller: nVidia Corporation Unknown device 05eb (rev a1)
05:00.0 VGA compatible controller: nVidia Corporation Unknown device 05eb (rev a1)
06:00.0 VGA compatible controller: nVidia Corporation G98 [GeForce 8400 GS] (rev a1)

nvidia-settings show the two cards but:

nvidia-smi:
NVIDIA: could not open the device file /dev/nvidia0 (Input/output error).
Failed to attach gpu
Could not allocate resources!

deviceQuery:
CUDA Device Query (Runtime API) version (CUDART static linking)
NVIDIA: could not open the device file /dev/nvidia0 (Input/output error).
There is no device supporting CUDA.

What can be the problem?

Thanks
Amir

I believe that the entries in /dev are not being created and you need to create them again with mknod - as in -

http://forums.nvidia.com/index.php?s=&…st&p=601788

-Nachiket