Forgot to add:
Unfortunately gdm is not in sid for amd64/i386 anymore. But fortunately
(probably because it is not c++), gdm from Squeeze works in Wheezy! So,
I installed gdm from Squeeze and my multiseat is working again.
Working gdm.conf is in attachment
--
Best regards, Sergey Spiridonov
# GDM Custom Configuration file.
#
# This file is the appropriate place for specifying your customizations to the
# GDM configuration. If you run gdmsetup, it will automatically edit this
# file for you and will cause the daemon and any running GDM GUI programs to
# automatically update with the new configuration. Not all configuration
# options are supported by gdmsetup, so to modify some values it may be
# necessary to modify this file directly by hand.
#
# This file overrides the default configuration settings. These settings
# are stored in the GDM System Defaults configuration file, which is found
# at the following location.
#
# /usr/share/gdm/defaults.conf.
#
# This file contains comments about the meaning of each configuration option,
# so is also a useful reference. Also refer to the documentation links at
# the end of this comment for further information. In short, to hand-edit
# this file, simply add or modify the key=value combination in the
# appropriate section in the template below this comment section.
#
# For example, if you want to specify a different value for the Enable key
# in the "[debug]" section of your GDM System Defaults configuration file,
# then add "Enable=true" in the "[debug]" section of this file. If the
# key already exists in this file, then simply modify it.
#
# Older versions of GDM used the "gdm.conf" file for configuration. If your
# system has an old gdm.conf file on the system, it will be used instead of
# this file - so changes made to this file will not take effect. Consider
# migrating your configuration to this file and removing the gdm.conf file.
#
# If you hand edit a GDM configuration file, you can run the following
# command and the GDM daemon will immediately reflect the change. Any
# running GDM GUI programs will also be notified to update with the new
# configuration.
#
# gdmflexiserver --command="UPDATE_CONFIG <configuration key>"
#
# e.g, the "Enable" key in the "[debug]" section would be "debug/Enable".
#
# You can also run gdm-restart or gdm-safe-restart to cause GDM to restart and
# re-read the new configuration settings. You can also restart GDM by sending
# a HUP or USR1 signal to the daemon. HUP behaves like gdm-restart and causes
# any user session started by GDM to exit immediately while USR1 behaves like
# gdm-safe-restart and will wait until all users log out before restarting GDM.
#
# For full reference documentation see the gnome help browser under
# GNOME|System category. You can also find the docs in HTML form on
# http://www.gnome.org/projects/gdm/
#
# NOTE: Lines that begin with "#" are considered comments.
#
# Have fun!
[daemon]
[security]
[xdmcp]
[gui]
[greeter]
[chooser]
[debug]
# Note that to disable servers defined in the GDM System Defaults
# configuration file (such as 0=Standard, you must put a line in this file
# that says 0=inactive, as described in the Configuration section of the GDM
# documentation.
#
[servers]
0=Standard0
1=Standard1
### per seat - these sections will need to be created ###
[server-Standard0]
name=Standard server
#command=/usr/bin/X -novtswitch -sharevts vt7 -isolateDevice PCI:2:0:0 -layout
seat0
command=/usr/bin/X -novtswitch -isolateDevice PCI:2:0:0 -layout seat0 vt7
flexible=false
[server-Standard1]
name=Standard server
#command=/usr/bin/X -novtswitch -sharevts -isolateDevice PCI:3:0:0 -layout
seat1
command=/usr/bin/X -novtswitch -isolateDevice PCI:3:0:0 -layout seat1 -sharevts
flexible=false
# Also note, that if you redefine a [server-foo] section, then GDM will
# use the definition in this file, not the GDM System Defaults configuration
# file. It is currently not possible to disable a [server-foo] section
# defined in the GDM System Defaults configuration file.
#
