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I've got a Linux box running SLES11SP1 with 4 NVIDIA GPUs in it, for running CUDA programs.

If the GPU is accessed by a process running as root, it changes the permissions on /dev/nvidia{0,1,2,3,ctl} to something inaccessible by non-root users. However, this behavior doesn't seem to occur when running on Ubuntu.

Does anybody know what would cause this behavior on SLES, and how to disable it?

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Are you specifically running a program as root? – penguin359 Apr 20 '11 at 1:13
@penguin359 - Sometimes I do specifically run a program as root that needs to access the GPUs. When this happens, the permissions are changed. – Lorin Hochstein Apr 20 '11 at 14:12
up vote 3 down vote accepted

Had same issue on SLES11sp1. Only way I could resolve it was to add the LDAP user account to the local machine's video group. I was told you could also change a line in /etc/modprobe.d/50-nvidia.conf from NVreg_DeviceFileMode=0660 to NVreg_DeviceFileMode=0666.

share|improve this answer
Setting NVreg_DeviceFileMode=0666 seems to have done the trick. – Lorin Hochstein May 13 '11 at 3:41

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