Running GPU on a Headless Ubuntu Machine

[EdH]

I'm running several machines headless using the "dummy" xorg driver and I remote VNC into them.

I've recently acquired a machine with an NVidia GPU card and set it up the same headless way. All works well in this dummy setup, until I install CUDA. When I install CUDA, I lose the VNC since I have no monitor connected. Is there a method to keep the NVidia driver and CUDA installed and available for GPU programming while still having the machine use the dummy driver so I can keep it headless?

[chris2be8]

I've got one system with a GPU in it where I don't use the GPU for screen output (it doesn't have the right sort of connector for the KVM switch I use). I had to update settings in the BIOS to make it use the onboard graphics for screen output. That might help.

Alternatively I would just SSH into the system and do all admin etc from the command line. Possibly plugging in a monitor etc to do initial setup, then run it headless.

Chris

[EdH]

Originally Posted by chris2be8

I've got one system with a GPU in it where I don't use the GPU for screen output (it doesn't have the right sort of connector for the KVM switch I use). I had to update settings in the BIOS to make it use the onboard graphics for screen output. That might help.

Alternatively I would just SSH into the system and do all admin etc from the command line. Possibly plugging in a monitor etc to do initial setup, then run it headless.

Chris

Thanks, Chris! I hadn't thought of the BIOS settings. I use the VNC windows, so I don't have to try to keep track of tmux terminals when running several things at once on the machines. Additionally, as you mentioned, the one monitor I have available near the headless machines also doesn't support any of the three NVidia GPU connectors, or I could just leave it plugged in.

As to SSHing, that's done frequently with all my "farm" and it's how I was able to uninstall the CUDA package and return the system to the previous state without physically working with it.

[M344587487]

You can buy a dummy hdmi connector on ebay to trick the card into thinking there's a display connected, but I don't know how well they work or if it solves your problem.

[EdH]

Originally Posted by M344587487

You can buy a dummy hdmi connector on ebay to trick the card into thinking there's a display connected, but I don't know how well they work or if it solves your problem.

You know, I hadn't thought of that since the 9-pin VGA days.* Thanks for reminding me, although I probably already have a spare monitor somewhere, too. I'm pretty sure the card would see the monitor even without a power cord, since I really don't have a single unused AC outlet left in that area.

I wouldn't think appreciably so, but is there any performance advantage in not having the GPU drive a monitor or dummy plug?

*I actually seem to remember building a VGA dummy plug using a few resistors.

[a1call]

Here is a DIY article for a dummy VGA connector if the card has one:

https://www.geeks3d.com/20091230/vga...ga-dummy-plug/

[M344587487]

I don't think you gain a noticeable performance advantage, I did some tests once switching between iGPU and dGPU as the monitor driver and if there was a difference it was hidden by margin of error.

[EdH]

Originally Posted by a1call

Here is a DIY article for a dummy VGA connector if the card has one:

https://www.geeks3d.com/20091230/vga...ga-dummy-plug/

That may have been what I did, but I put the resistors into the plastic connector hood. I'm sure a DVI or Display Adapter dummy would be a bit more involved. . .