As every one knows Alex and I do lots of work with Nvidia Graphics cards and CUDA password cracking. I recently encountered the following error when trying to boot Backtrack 4 Linux on our CUDA server. Below I explain the error and why it happens and how to fix it.
The error message will be similar to this:
NVIDIA: could not open the device file /dev/nvidia2 (Input/output error)
The error happens on 32 bit linux systems when you try to initiate more graphics cards than the kernel can allocate memory for. This does not happen on 64 bit systems. It is still possible to run multiple high end cards such as the 295GTX by adding a statement to your kernel line in the grub menu.
open up the grub file in a editor: (I like vi)
- vi /boot/grub/menu.lst
Locate the line that defines your kernel parameters: (it will look similar to this)
- kernel /boot/kernel-2.6.31-bt-r6 root=/dev/sda3
Once you find it add the following string to the end of it like this:
- kernel /boot/kernel-2.6.31-bt-r6 root=/dev/sda3 vmalloc=256M
Save the file and reboot. This will allocate the kernel some extra memory to handle the graphics cards and now you should be able to access the graphics devices properly.