SPICE EDD for Ultrawide resolution via Nomachine

[gurpal2000]

Hi,

I gave set up the latest Mint Cinnamon VM in proxmox. My monitor is an LG Ultrawide 2560x1080 (21:9 ratio)

Constraint: I have to use the SPICE display and audio driver because audio doesn't work in nomachine without SPICE.

With that out of the way... Nomachine works great. But....

When playing around with the display options in nomachine (eg. fullscreen + resize remote), i find that out of the box nomachine will resize to 1920x1080 only leaving black bars.

There is a workaround (on stack) which enables the ratio and I can manage this for the time being.

The question is: where is the problem why the 21:9 option isn't presented in the first place to linux. Is it proxmox ? SPICE driver?

BTW - I've tried a number of distros and they all display (no pun intended!) this problem.

thanks

 

[BobhWasatch]

NoMachine has two modes. One grabs control of the physical display and forwards it to the client. In a VM the "physical" display will be the one running when NoMachine connects. If you have a display manager like sddm or xdm or lightdm or whatever running, then you have a "physical" display and by default NoMachine will use that. You will be limited to the resolutions it supports. That also explains why you need SPICE enabled to get sound.

On the other hand, if you are not running a display manger then NoMachine will create a "virtual" display. This is the mode I use. I don't have 21:9 monitor but I do have working sound even without SPICE. I think there's a way to configure NoMachine to work this way even if there is a physical display present, but I haven't tried it.

My suggestion is to stop your display manager and see if that works better.

 

[gurpal2000]

NoMachine has two modes. One grabs control of the physical display and forwards it to the client. In a VM the "physical" display will be the one running when NoMachine connects. If you have a display manager like sddm or xdm or lightdm or whatever running, then you have a "physical" display and by default NoMachine will use that. You will be limited to the resolutions it supports. That also explains why you need SPICE enabled to get sound.

On the other hand, if you are not running a display manger then NoMachine will create a "virtual" display. This is the mode I use. I don't have 21:9 monitor but I do have working sound even without SPICE. I think there's a way to configure NoMachine to work this way even if there is a physical display present, but I haven't tried it.

My suggestion is to stop your display manager and see if that works better.

If I understand correctly: don't enable the DM by default on boot? It's Mint Cinnamon so i think it uses lightdm.

 

[BobhWasatch]

If I understand correctly: don't enable the DM by default on boot? It's Mint Cinnamon so i think it uses lightdm.

Yeah, that's what I'm suggesting.

ETA: You might also need to edit /usr/NX/etc/node.cfg to set your preferred desktop. Mine for a Debian 12 VM is:

DefaultDesktopCommand "env -u WAYLAND_DISPLAY /usr/bin/dbus-launch --sh-syntax --exit-with-session /usr/bin/startxfce4"

The WAYLAND_DISPLAY thing is there because my home dirs are on NFS and some of the machines use Wayland but not this one.

 

[gurpal2000]

Yeah, that's what I'm suggesting.

ETA: You might also need to edit /usr/NX/etc/node.cfg to set your preferred desktop. Mine for a Debian 12 VM is:

DefaultDesktopCommand "env -u WAYLAND_DISPLAY /usr/bin/dbus-launch --sh-syntax --exit-with-session /usr/bin/startxfce4"

The WAYLAND_DISPLAY thing is there because my home dirs are on NFS and some of the machines use Wayland but not this one.

Ok this might turn into a longer thread!

Did you start off with vanilla Debian without a display manager first? Then add X/wayland and a DM?
What is your display driver and did you add an audio device from the outset?
Is there a guide you followed? (eg. https://www.apalrd.net/posts/2022/raspi_spice_login/)

(NB. I did have some success with the display size, so thank you. Maximises fine, but guess what.... no sound at all)

 

[BobhWasatch]

I didn't follow any guide, I've been doing Linux admin for a very long time. I read the NoMachine docs and looked at their forums when I had issues.

The VM is question was installed a couple of years ago and has gone through some iterations. IIRC it was originally installed with Debian 11 + XFCE4. I disabled the DM and installed xrdp. Used it that way with Apache Guacamole for a while until I found NoMachine. Just replaced xrdp with NoMachine without changing anything else, at least that I can remember.

Glad to hear you got the display sorted. Regarding sound, you might look further into that node.cfg file. There are some settings for PulseAudio:

EnableAudio 1
CommandStartPulseAudio "/usr/bin/pulseaudio --high-priority=no"

This may be the default, I don't recall. But I do get sound via NoMachine. I have the ICH9 Audio controller enabled for the VM but I don't think that really matters for virtual sessions. It is booting with Legacy BIOS, not UEFI, but again I don't think that matters. I am using Pulseaudio rather than Pipewire on that VM. There used to be some issues with Pipewire and NoMachine, I don't know if those have been fixed. You might look at the NoMachine forums for more info.