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cjsmall
February 7th, 2016, 12:01 AM
OS: Xubuntu 15.10
GPU: Nvidia Quadro K4000 with nvidia-352-63 driver

I asked this question on the Xfce forum and got no responses, so I decided to repost the question here.

I have two independent monitors configured in a left-right setup using the Nvidia X Server Settings tool. The /etc/X11/xorg.conf file looks like this:


Section "ServerLayout" Identifier "Layout0"
Screen 0 "Screen0" 0 0
Screen 1 "Screen1" LeftOf "Screen0"
InputDevice "Keyboard0" "CoreKeyboard"
InputDevice "Mouse0" "CorePointer"
Option "Xinerama" "0"
EndSection

Section "Files"
EndSection

Section "InputDevice"

# generated from default
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/psaux"
Option "Emulate3Buttons" "no"
Option "ZAxisMapping" "4 5"
EndSection

Section "InputDevice"

# generated from default
Identifier "Keyboard0"
Driver "kbd"
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Planar Systems, Inc."
ModelName "PX212M"
HorizSync 31.0 - 92.0
VertRefresh 56.0 - 86.0
Option "DPMS"
EndSection

Section "Monitor"
Identifier "Monitor1"
VendorName "Planar Systems, Inc."
ModelName "PX212M"
HorizSync 31.0 - 92.0
VertRefresh 56.0 - 86.0
EndSection

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "Quadro K4000"
BusID "PCI:4:0:0"
Screen 0
EndSection

Section "Device"
Identifier "Device1"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "Quadro K4000"
BusID "PCI:4:0:0"
Screen 1
EndSection

Section "Screen"
Identifier "Screen0"
Device "Device0"
Monitor "Monitor0"
DefaultDepth 24
Option "Stereo" "0"
Option "nvidiaXineramaInfoOrder" "CRT-0"
Option "metamodes" "DVI-I-0: nvidia-auto-select +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection

Section "Screen"
Identifier "Screen1"
Device "Device1"
Monitor "Monitor1"
DefaultDepth 24
Option "Stereo" "0"
Option "metamodes" "DP-2: nvidia-auto-select +0+0"
Option "SLI" "Off"
Option "MultiGPU" "Off"
Option "BaseMosaic" "off"
SubSection "Display"
Depth 24
EndSubSection
EndSection

When I login I get my standard xfce4 desktop on the right screen (DISPLAY :0.0) which has the xfce4-panel.

To the left (DISPLAY :0.1), I get an empty default xfce4 background image. However, this is being managed by the same desktop manager as the right screen. There is no panel on the left screen, and if I type xfce4-panel --display :0.1 on either screen I get the message: "xfce4-panel: There is already a running instance"

Here are the relevant xfce4 and window management process that are actually running:



/usr/sbin/lightdm
/usr/bin/X -core :0 -seat seat0 -auth /var/run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch lightdm --session-child 12 19
/bin/sh /etc/xdg/xfce4/xinitrc -- /etc/X11/xinit/xserverrc
xfce4-session
/usr/lib/x86_64-linux-gnu/xfce4/xfconf/xfconfd
xfce4-panel --display :0.0 --sm-client-id [UUID]
xfsettingsd --display :0.0 --sm-client-id [UUID]
xfdesktop --display :0.0 --sm-client-id [UUID]

I can right-click on the left screen and get the desktop menu which allows me to open certain applications on that screen. For example, I can set a separate wallpaper on display :0.1 and open applications like a web browser. However, when I try to open an xfce4-terminal, one appears while some of the xfce4-terminals already opened on display :0.0 are blown away -- and vice versa. (This is likely some strange coding bug in xfce4-terminal.)

I'm not sure why xfdesktop --display :0.0 is managing display :0.1 as Xinerama is not enables.

What I want is to have two completely independent desktop/window managers with independent xfce4-panels, running on each monitor, with only the mouse being able to move between the two screens. The startx command has a display option (not well documented) but most of the other desktop commands do not.

There are a number of posts from 2011-2012 asking about this, but no clear solutions. I've been running in this two-headed mode on a Sun Solaris system with the openwin (i.e. gnome) desktop for the past 20 years or so. Yet, I have not been able to find any documentation on how to configure this for Xubuntu. Does anyone have the solution? Any pointers would be greatly appreciated.

echo59
March 29th, 2016, 10:02 PM
Hi,

I seem to be having a similar problem to you. I've no experience at all managing 2 screens. Any advice you can give me? My thread is at http://ubuntuforums.org/showthread.php?t=2318669

Any advice or suggestions you can give me would be much appreciated.