It would be nice to have a newbe-friendly configuration (GUI) for a multihead configuration over network.


Old computers or laptops with a network card are nearly free compared to expensive multihead graphic cards and big screens. With a multihead over network gui it's possible to extend ones screen without buying expensive hardware and without much knowlege about X-Servers. The reaction delay of 200-500 ms is acceptable for a second monitor (with a 100Mbit/s wired network).

Use cases

  • Joe Video wants to edit his holiday videos confortably on his laptop pc. As it only has one small screen and no graphical output he has not enought place for the preview screen, the library and the time-bar of his video-editor-software. With multihead-over-network he connects his girlfriends laptop to the network and now has a dedicated preview screen.
  • Ralph Developer has got used to programm with two screens from his job. As he doesn't earn so much he can't afford a new second monitor and a dualhead graphic card. As he additionally has a laptop for on the go, he can use it as a desktop-enlargement while developing.



Both alternatives would use xdmx with xinerama to get one big virtual screen. An option to provide the possiblity to configure different screens can be implemented later.

First implementation will focus on Gnome support. The port on kdm/kde shouldn't be a problem afterwards.

The best solution would be to create a GDM-tool that creates a new Button in GDM. If you start that function it starts a xdmx-server with a previously selected ip-address and a new gdm on top of it. The tool also could configure the xhost-permissions on the xdmx-server. xhost-permissions on the remote screen could be set up with a similar script.


  • None yet. Script for manual start after killing X exists and works. (soon goes into a PPA)

Outstanding issues

  • Before the session is started we normally don't have any active network connection (nm-applet isn't running yet)
    • --> get TCP/IP up by adding "auto eth0\n iface eth0 inet auto" to /etc/network/interfaces works. But the interfaces aren't manageable by nm-applet any longer if we do so.

  • Unsure if we still have root privileges in GDM 2 to restart X on top of XdmX
    • --> needs testing


  • GDM 2's GUI seems to be defined by /usr/share/gdm/ so adding a button isn't really difficult (thx to glade)
  • Didn't succeed to set the button's action, can somebody give me a hint where to do that?


multihead-over-network-gui (last edited 2010-03-22 20:27:44 by 178-82-214-45)