How do I open a second X simultaneously?

How do I open a second X simultaneously with different resolutions? Is it possible? I use primarily 1280 X 1024 16bit color, but I' d like to have a new X running at 800 X 600, to watch my nvidia tv output.
Thank you!

How do I open a second X simultaneously with different resolutions? Is it possible? I use primarily 1280 X 1024 16bit color, but I' d like to have a new X running at 800 X 600, to watch my nvidia tv output.

The first thing that comes to mind is to try the Nested X Server. There was an article about it in the March issue of Linux Journal. The article is online at

http://www.linuxjournal.com/article.php?sid=7298

Hope that helps a bit...

edit /etc/X11/Xservers
There is a line in there for X displa :0, you need a new line for :1 or whatever X display number you desire. Then you need to pass a parameter to make it use a different config to your original server. One tricky way to do it might be to define 24bit colour to run at a highres, and 16 bit colour as 800x600 in the normal config, then pass in a colour depth of 16 to get 800x600....


Old post:
X is simply a running program, but it is initialised from your startup scripts.

All you need to do is copy your X config, make the appropriate changes, and run an additional X server or login manager using that config file. I used to run 4 X servers so that other people could login seperately, but then KDE added an option to do that when the desktop is locked....

Also, depending on which login manager you use you can convince it to start a second session on a new virtual console. kdm lets you pass in a "config" parameter to specify an alternate configuration file.

You can start a new X session by running "startx -- :1". You go back to the old one by pressing ctrl-alt-F7 and switch to the new with ctrl-alt-F8. You can change the resolution by pressing ctrl-alt- +/-

I take it there is no reason why the 2 sessions need to be using the same Desktop Environment ?

how could i get the second X to use for example icewm, and keep my first X using KDE (without having to constantly change the contents of .xinitrc ?)

$ startx /path/to/wm -- :1

That'll do the trick. For example, if you are using IceWM (like me because I'm cool) but you want to try and futz around with GNOME that was installed because you didn't want broken libraries for you GTK apps, you would type (in tty2)

$ startx /usr/bin/gnome-session -- :1

And GNOME will load in the CTRL+ALT+8.

If I am already in x it is as :1 I have to use startx -- :2 in a console to open a new one

Running X on multiple virtual consoles may not work (or not work well) with certain video drivers. When I use NVidia's closed-source binary, it gives me nothing but trouble. The open-source nv driver lets me start X on multiple consoles with no difficulty.

If you have problems doing it the simple way that should work, it might have to do with drivers.

I manage two start two xservers on two seperate vt's, but how do I get two xserver running on two desktops without having to switch them with ctrl-f8???

The idea is to to run a touchscreen on a seperate x, with no keybord an only the touch as device, while the main application runs on a seperate x with keyboard and mouse.

Thanxs

I have no firsthand knowledge of this but using startx with specifying a different xf86config file or making a different screen(or it may be another section, it's where it tells what the xserver is supposed to use.)
I am a little confused though, are you wanting to run a x server on one monitor and another x server on another monitor? I have never heard of success with that but maybe I'm just wrong .

That is xinema, it allows 1 desktop to span 2 monitors.

BBut you need to do minor changes with a dual-headed vid card.
With two seperate video cards I do not know if its possible.

It's for a special application. I want a kind of menu on the touchscreen (Elotouch) and a main application on another monitor.
The problem is, I don't want have mouse support on the tochscreen but only the Elo Touch as input device. So both screens have to be completely seperated.
If I use multihead I can move the mouse to the touch and back.
Can I tell the mouse not to go to the second screen in mutliscreen layout?

Taken from the man page of X (7)

Display Names From the user's perspective, every X server has a display name of the form: hostname:displaynumber.screennumber This information is used by the application to determine how it should connect to the server and which screen it should use by default (on displays with multiple monitors): hostname The hostname specifies the name of the machine to which the display is physically connected. If the hostname is not given, the most efficient way of communicating to a server on the same machine will be used. displaynumber The phrase "display" is usually used to refer to collection of monitors that share a common keyboard and pointer (mouse, tablet, etc.). Most workstations tend to only have one keyboard, and therefore, only one display. Larger, multi-user systems, however, frequently have several displays so that more than one person can be doing graphics work at once. To avoid confusion, each display on a machine is assigned a display number (beginning at 0) when the X server for that display is started. The display number must always be given in a display name. screennumber Some displays share a single keyboard and pointer among two or more monitors. Since each monitor has its own set of windows, each screen is assigned a screen number (beginning at 0) when the X server for that display is started. If the screen number is not given, screen 0 will be used.

As I understand it you are trying to set up two displays, not two screens.
I don't know if it works to set up two display when you have the same graphics card for both of them.