Virtual Terminal switching with a multiseat setup and lightdm

Rereading the wiki entry under https://help.ubuntu.com/community/MultiseatX, I guess you should have a look at how X is invoked; e.g. the -sharevts and -novtswitch command line options should be somehow passed to X in your lightdm.conf.

If you have a working state, please consider updating the wiki entry to 11.10.

Thanks for the hint. The -sharevts switch was the key. It is not added by default by Lightdm. I looked at /var/log/lightdm/lightdm.log and added a custom xserver-command option and now it finally works! Thanks for your help.

My final lightdm.conf:

[SeatDefaults]
greeter-session=unity-greeter
user-session=ubuntu

[Seat:0]
xserver-layout=default
xserver-command=/usr/bin/X :0 -layout default -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch -sharevts

[Seat:1]
xserver-layout=displaylink
xserver-command=/usr/bin/X :1 -layout displaylink -auth /var/run/lightdm/root/:1 -nolisten tcp vt8 -novtswitch -sharevts