Multi X-session setup

[Tomas Carnecky]

tech at tnet.no wrote:
> I don't have this equipment yet, but I will get it later today hopefully.
> 
> Motherboard: MSI K9AG NEO2-Digital, AMD 690G+SB600, Socket-AM2, ATX,DDR2, DVI+HDMI, PCI-Ex16 with integrated ATI Radeon X1250 GPU.
> PCI-Expreses video-card: Sapphire Radeon HD 2400 PRO 256MB DDR2, DVI-I/Tv-out/HDMI
> 
> What I want is two have two seperate X sessions, with two displays, one with tv or projector, the other my LCD monitor. Also, only one set of keyboard and mouse.
> 
> The tv/projector one will be mainly be used to view high-quality video (1280p or 720i in xvid or x264) through mplayer, the other monitor will just be for general stuff.

( Just a little correction: 1280p doesn't exist, it's either 1080p/i or
720p/i )

> I want the video/picture at the X-sessions to be active at the same time, but with ability to switch between what X-session mouse and keyboard will be active/controlling to.

To have two separate X sessions, you'd have to start two instances of
the xserver, each with its own "ServerLayout" in xorg.conf. Each
instance would run on its own VT and you'd have to switch between those
with ctrl+alt+Fx. But in this setup I don't think it's possible that the
two xservers have both monitors enabled at all times, meaning that the
inactive xserver will disable its monitor. I have never tried that setup
so don't take my word for it.

> I know there's an option for dual screen set-up, but this is not something I quite feel comfortable with.

Why not?

> What driver that will be used for whatever card is not something I worry about either, I don't mind if there's two different drivers or if any of them is closed source.
> 
> Is this possible and if so could someone hint me to how to do it, either in an explanation or a reference to documentation? 
> If it is not, could someone please list similiar options I could try?


I suggest you start only one xserver and configure two independent
screens in xorg.conf. That allows you to move the mouse from one screen
to the other (which is very quick compared to a VT switch), yet the
screens remain independent in the meaning that you can't drag windows
between the two screens. If you also use xrandr you'd be able to disable
one screen if it's not in use!
I'm currently running that setup with one nvidia card, two monitors,
using the nvidia blob. I could help you with the basic setup but I have
no idea about which ati driver you'd need. There's plenty of
documentation about multi-screen setups on the internet.

tom