Re: [gentoo-user] Virtual Desktop with a Virtual Monitor?

[Mark Knecht <markknecht@gmail.com>]

On Mon, Nov 8, 2021 at 1:31 PM Laurence Perkins <lperkins@openeye.net> wrote:
>
>
>
> > -----Original Message-----
> > From: Mark Knecht <markknecht@gmail.com>
> > Sent: Monday, November 8, 2021 11:48 AM
> > To: Gentoo User <gentoo-user@lists.gentoo.org>
> > Subject: Re: [gentoo-user] Virtual Desktop with a Virtual Monitor?
> >
> > On Mon, Nov 8, 2021 at 12:23 PM Andreas Stiasny <gentoo@lists.stiasny.priv.at> wrote:
> > >
> > > On 08.11.21 17:34, Mark Knecht wrote:
> > > > In the case where the monitor is detached at boot two modules are
> > > > not loaded - fuse & nvmem_rmem. Other than that the module list
> > > > appears identical.
> > > >
> > >
> > > At the moment I can't help you to solve this in software but there may
> > > be a hardware solution. There are fake monitor plugs. This is just a
> > > plug without a cable that makes the device think that there is a
> > > monitor attached even if there isn't. Search for "HDMI dummy plug" or similar.
> > >
> > >
> > > Andreas
> > >
> >
> > Actually, if it works and I have little doubt it does, that's a great solution for my needs. I see Amazon has 1920x1080 plugs but also has virtual 4K plugs. All under $10.
> >
> > Thanks!
> >
> > Mark
> >
>
> So, I don't use the PI variants with GUI or even with a monitor very often, but as I recall if the HDMI port isn't attached at boot it then disables it to save the video memory.
>
> If you then try to use one of the VNC servers that's designed to share the running X session, you'll find that there isn't a running X session.
>
> But what you should still be able to do is install the "vncserver" command to fire up an X server that isn't attached to the physical output, only the VNC.
> You may need to configure it to also start your preferred display manager, etc depending on whether or not the distro you're running does that automatically for you.
>
> If you want to be able to plug in a monitor later though you'll probably need one of the dummy plugs to prevent the output from being switched off and ignored.
>
> LMP

So I don't yet know how they do it but I purchased a copy of a product called
StellarMate OS yesterday.

https://stellarmate.com/

It's a Pi variant that is set up to control
astrophotography equipment. It's able to run headless and has a web server
that I can access from Chrome on my main Linux box.

https://drive.google.com/file/d/1I6QYXay6rTy_-CDFQpsQBaSaiyOjNFDJ/view?usp=sharing

Screen resolution drops from 1920x1080 with the monitor attached to
1600x900 headless,
but other than that it appears to work fine. Interestingly the taskbar
across the top isn't
accessible, at least yet, but I can run anything I have an icon on the desktop.

I'll be studying how they do this (although I think the headless
monitor plug is probably the
easiest solution) so if someone (Wol?) wants to work offline, get in touch.

Cheers,
Mark