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

[Mark Knecht <markknecht@gmail.com>]

On Sun, Nov 7, 2021 at 2:04 PM Wol <antlists@youngman.org.uk> wrote:
>
> On 07/11/2021 20:39, Mark Knecht wrote:
> > Hi,
> >     I've been playing with a Raspberry Pi 4 as a utility divice for a
> > couple of purposes - a backup server for here at home as well as an
> > astrophotography manager to run my camera and mount. So far everything
> > is fine when I have a monitor attached. I can ssh in and run X apps,
> > and I can run the VNC client and control the desktop.
> >
> >     What I find, however, is that when I boot the RP4 without the
> > monitor attached, which I would be doing most all the time, I lose the
> > desktop functionality through VNC. I can still ssh X apps, and both
> > xdpyinfo and xrandr still say the X resolution is 1920 x 1280, but
> > there doesn't appear to be a real desktop for VNC to latch onto.
> >
> >     I get that this must be possible as essentially VirtualBox is able
> > to do this. I wonder if there's a way for mere mortals to do something
> > similar?
> >
> I'm guessing the reason there isn't a virtual desktop is because
> nobody's logged in AT THE PI and started one!
>
> Just start Xorg over ssh, or plasma-wayland, or whatever. Sorry I don't
> (yet) know how to do it, I need to find out because I want to do exactly
> the same :-)
>
> Cheers,
> Wol
>

Wol,
   Yeah, you may be right, although it wasn't what I was thinking. If
I start Xorg over ssh then it's running there but visible here. Then I
need to do some sort of disconnect, leaving it running so X apps can
go on working.

   If it was like a true 'virtual monitor' then in my mind it's
running there, not getting displayed on a physical screen, and I
connect to it like it was a real monitor but it would just be a VNC
connection and not some sort of way of leaving X11 hanging, or so I
thought.

   I did find this which is more or less what you're suggesting:

https://unix.stackexchange.com/questions/327532/how-to-remotely-log-in-with-full-graphical-desktop-over-x11

   Turns out the RP4 OS is doing something different than Ubuntu
running on the RP4. In the case of the RP OS VNC connects but tells me
it cannot display the desktop at this time. In the case of Ubuntu
running on the RP4 VNC just doesn't connect.

   If I find a solution I'll check back in. Possibly someone else has
some ideas and we'll  get a response in the next few days.

Mark