# xorg.conf (X.Org X Window System server configuration file)
#
# This file was generated by dexconf, the Debian X Configuration tool, using
# values from the debconf database.
#
# Edit this file with caution, and see the xorg.conf manual page.
# (Type "man xorg.conf" at the shell prompt.)
#
# This file is automatically updated on xserver-xorg package upgrades *only*
# if it has not been modified since the last upgrade of the xserver-xorg
# package.
#
# If you have edited this file but would like it to be automatically updated
# again, run the following command:
# sudo dpkg-reconfigure -phigh xserver-xorg
Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "XkbRules" "xorg"
Option "XkbModel" "pc104"
Option "XkbLayout" "us"
EndSection
Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
EndSection
Section "Device"
Identifier "Configured Video Device"
EndSection
Section "Monitor"
Identifier "Configured Monitor"
EndSection
Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Subsection "Display"
Virtual 2560 1024
EndSubsection
EndSection
--------------------------------
xrandr output:
Screen 0: minimum 320 x 200, current 2560 x 1024, maximum 2560 x 1024
VGA_1 connected 1280x1024+1280+0 338mm x 270mm
1280x1024 60.0*+ 75.0 59.9 60.0*
1440x900 60.2
1280x960 60.0
1280x800 60.0
1152x864 75.0 74.9
1280x768 60.0
1152x768 54.8
1024x768 84.9 85.0 75.1 75.0 70.1 60.0
832x624 74.6
800x600 84.7 72.2 75.0 60.3 56.2
640x480 84.4 75.0 72.8 72.8 75.0 66.7 60.0 59.9
720x400 70.1
TV_7PIN_DIN disconnected
DVI-I_1/digital disconnected
DVI-I_1/analog connected 1280x1024+1280+0 338mm x 270mm
1280x1024 60.0*+ 75.0 59.9 60.0*
1440x900 60.2
1280x960 60.0
1280x800 60.0
1152x864 75.0 74.9
1280x768 60.0
1024x768 75.1 70.1 60.0
832x624 74.6
800x600 72.2 75.0 60.3 56.2
640x480 75.0 72.8 75.0 60.0 59.9
720x400 70.1
-----------------------------
I run
$ xrandr --output DVI-I_1/analog --left-of VGA_1
shows me the same half of the virtual desktop on both monitors
$ xrandr --output VGA_1 --right-of DVI-I_1/analog
shows me the same half of the virtual desktop on both monitors
I'm stumped.