How to run 2 X sessions with different display managers?

Question

I read about the virtual terminals a little and that gave me an idea. I searched for a way to have two X sessions simultaneously.

I had a look at these sites :

1. How to run multiple user X sessions on the same computer, at the same time?
2. How to drag windows between 2 X servers?

I tried startx -- :1 but my earlier terminal (on Ctrl+Alt+F7) hung up. How do I ensure this does not happen?

My main need is to get Unity on :0 and Gnome-shell on :1 and switch between them like workspaces.

If possible, I'd like to get login screen on tty8 or get option of logging into a different account.

As per question 2, exchanging windows between sessions is not recommended as it is not easy. But if it is possible I'd like to know.

I have Ubuntu 12.04 64bit.

The above command made both sessions crashed (virtual one worked for 15 min then crashed when I switched to real).

Also, how to revert to one X session if system gets overloaded?

Update :

Tried code in answer 3 times but system never stabilizes. Either tty7 or tty8 works, but not simultaneously, for sometime before crashing.

Solution 1

Questions #1: How to run multiple X sessions at the same time

You need to run sudo startx gnome-session -- :1 vt8 - the vt8 tells X to start the session on TTY8 (which you get to with ctrlaltF8)

Question #2: Drag windows between X Sessions

I doubt that's possible, and if it is, with the software we have today it would be very unstable - it's the job of the DE to do everything from window management and toolbar rendering to workspace placement, and you can't just 'cut and paste' a window from one DE to another. In the future this could be possible, as it sounds like something the Wayland graphics server (hoped to be a replacement for X) could be better at managing. But for the moment at least, it's unlikely to work.

Solution 2

I am using 2 different sessions on Ubuntu like this:

• Create new user
• CTRL+ALT+L (switch account)
• Log into using that user

Ubuntu creates new X session in next tty when another user logins. So now you can switch between those sessions using CTRL+ALT+F7 and CTRL+ALT+F8.

I've never tried with Gnome3 but it works with XBMC session

Comments

[VedVals]

And what about 2nd query? How to do that? Will such a system be stable?

[jackweirdy]

A second X session shouldn't cause any problems as when you switch TTYs the X server that's "in focus" should get controlled by your input devices (IE mouse and keyboard). This is the system I currently use to have the chromeOS desktop environment running alongside Unity.

[VedVals]

No I meant how to exchange windows. Also the command I tried (one in question) might not be the one as now both terminals are hanged.

[jackweirdy]

You should clarify in your question that exchanging windows is a requirement; you don't mention it anywhere

[VedVals]

I edited the question to clear it. Any suggestions?

[VedVals]

What happened to the earlier answer? Keep it too. Add this as an update.

[VedVals]

Tried the code 3 times. System just crashes.

[daboross]

This does seem to work! Do you know if this works running multiple DEs?

[Kokizzu]

i've been using this for ages, but i got problem: unix.stackexchange.com/questions/600381