Arch Linux

haevaristo

Member

Registered: 2021-02-03

Posts: 5

Headless Server installation

Hi

So, bare with me lots of new things to figure out and I am hoping someone can make it easier... this is my first time installing Arch Linux.

The end goal is to have a headless server running several GPUs doing some crypto mining but I have decided to grow it small so I could learn about the different software at play here.

For now, the first step would be to be able to overclock the GPU, I have a single nvidia GPU connected to the system.
I typically use ssh to control the server remotely however, because It seems that nvidia requires a running xserver to be able to overclock, I decided to try and setup VNC.

So I was trying to understand the guide on https://wiki.archlinux.org/index.php/TigerVNC

I am not sure, but I have followed the instructions top to down and I have enabled the x0vncserver.service and the xvnc@.service, I have a feeling they should be mutually exclusive but its not clear on the guide.
Now I believe xvnc service is setup correct since I could vnc into the machine, but I would be greeted with a black screen.

So, I assumed that the graphical login was missing. Following this guide https://wiki.archlinux.org/index.php/XDMCP I got xdm running, and then vnc would greet me with a login prompt.
But then on this guide https://wiki.archlinux.org/index.php/XDM, I wanted xdm to start running with systemctl .. this seemd to work fine but when I tried to replace it with the xdm-archlinux themed version now it doesnt start any longer.

sudo systemctl status xdm-archlinux

shows ""Failed to start X-Window Display Manager.".

sudo journalctl -xe

does not provide anything useful I can see...

haevaristo

Member

Registered: 2021-02-03

Posts: 5

Re: Headless Server installation

So, I have moved a bit forward in my understanding. And in the meantime I had to do a clean install again, so this time around I did not installed xdm but rather went straight to xdm-archlinux .. I believe that is working now, I have however not yet completely tested it.

I did found out one of the issues I was having with the nvidia-settings tool not working, was related to the DISPLAY and XAUTHORITY.
When setting those env vars to the correct values, then it is finally working. I am now wondering is how should those be configured.
Currently I am checking for the status of the XAuth by looking at the output from systemctl status xdm-archlinux ...
I am looking for the proper way to automate this step so I wont have to manually set the environment variables every time, can perhaps someone help out ?
Where can I find a good, down to earth, explanation of this xauth mechanism, purposes, etc... the man pages are too cryptic for someone just beginning reading this.

I have also now manually created a xorg.conf file, despite seeing several advise not to do it but my understand now is that this is the only way to have an headless system running.

PS: Can one of the admins, maybe move this to the newbie corner ? I realized now there is a newbie corner and this is perhaps better suited there.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,343

Re: Headless Server installation

Moving to NC

How and where are you running nvidia-settings ? DISPLAY and XAUTHORITY are set within the context of the xorg server for the relevant xorg instance. so technically looking at the status of xdm will indeed give you this information, but so will running nvidia-settings when inside the xorg session

haevaristo

Member

Registered: 2021-02-03

Posts: 5

Re: Headless Server installation

Hummm .. perhaps I could have explained better ... I am trying to run a headless server.
I leave it running and send logs and monitoring information to a collection server that I use to monitor the status.
When needed I ssh into it.
However, .. because I need to overclock the Graphics card.. and nvidia requires an xserver running in order to allow overclocking (as far as I understood it) ... then I was trying to setup an tigerVNC server that I could then overclock the GPUs as well as login remotely if I would prefer so instead of SSH.

So, for now ... everything I described is from an SSH remote connection perspective ... so I am not inside X ... I am trying to figure out the command line parameters to setup the overclock on the GPUs so that later I can brew my own systemd script that sets up everything on startup..

haevaristo

Member

Registered: 2021-02-03

Posts: 5

Re: Headless Server installation

So ... I am currently still struggling with these environment variables DISPLAY and XAUTHORITY ...
I am trying to setup a systemd unit service that runs the nvidia-settings command automatically ... however, currently I need to manually setup the DISPLAY and XAUTHORITY vars, so I have no clue how to do that automatically so that systemd can run the script sucessfully
I did found this "If NO ONE is logged into an X session yet, but there is a greeter login program like "gdm", "kdm", "xdm", or "dtlogin" running, you will need to find and use the raw display manager MIT-MAGIC-COOKIE file."
It seems to sort of explain my issue .. however I am clueless how to configure it properly ... anyone ?!?

Last edited by haevaristo (2021-03-06 21:47:03)