Category: LightDM

Dual monitor on Xubuntu 11.10

I had to setup a new machine with installed an Nvidia graphic card and two monitors connected as follow:

  • 24” monitor on the left connected through DVI and a native resolution of 1920×1200
  • 19” monitor on the right connected through DSUB and a native resolution of 1280×1024

At first I tried to configure the two monitors working with the proprietary Nvidia driver, with the Xinerama option enabled, but I had some problems for which I couldn’t find any workaround by a short time. So following how I setup up my machine using Nouveau.

First of all let we know which graphic controller do we have as a reference

sudo lshw -c display

  *-display               
       description: VGA compatible controller
       product: GT218 [GeForce 210]
       vendor: nVidia Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a2
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nouveau latency=0
       resources: irq:16 memory:ed000000-edffffff memory:c0000000-cfffffff memory:de000000-dfffffff ioport:df00(size=128) memory:d0000000-d007ffff

Ok, we have a GeForce 210 and effectively nouveau is being using.

By default the issue was the wrong resolution at the login prompt of LightDM, this because the graphic card were showing the desktop in both the monitors,  a kind of “twin view”  and both the resolutions were set to 1280×1024. The 24” resolution was adapted to the 19”.

To change the layout of our monitors configuration, such as the resolution or how they are positioned, we can use xrandr or better a gui version of it like grandr or arandr.

Install them with a simple

sudo apt-get install grandr arandr

Arandr has the nice feature for which you can save the script file and use it later while grandr shows the final layout better. Anyway, start arandr

arandr

and edit your configuration, at the end I had something like this:

 

now save the configuration somewhere through the menu Layout->Save As for example lightdm_xrandr.sh in your home directory.

In my case this is the file generated

cat ~/lightdm_randr.sh

#!/bin/sh
xrandr --output VGA-1 --mode 1280x1024 --pos 1920x0 --rotate normal
       --output DVI-I-1 --mode 1920x1200 --pos 0x0 --rotate normal
       --output HDMI-1 --off

Move the script to /usr/share and edit the LightDM configuration to recall it at boot

sudo mv ~/lightdm_xrandr.sh /usr/share
sudo chmod 755 /usr/share/lighdm_xrandr.sh

open the config file and add the script path

sudo gedit /etc/lightdm/lightdm.conf

insert at the end

display-setup-script=/usr/share/lightdm_randr.sh

Reboot and see if everything goes right.

 

Autologin on Xubuntu

I recently moved to XFCE 4.8 which I find the closest desktop environments to Gnome 2.x. Until now Unity and Gnome Shell can’t give me back the productivity I used to before. Yes, XFCE is a step down than Gnome 2.x but it needs only some personalizations to be on a par with it.

For example there is no options to auto login, following how to enable it.

Edit the LightDM file configuration

sudo nano /etc/lightdm/lightdm.conf

in the section SeatDefaults, add the first two lines in order to have:

[SeatDefaults]
autologin-user=YOURUSERNAME
autologin-user-timeout=0
user-session=xubuntu
greeter-session=lightdm-gtk-greeter

I tried to set the timeout to 5 seconds but it seems it has no effect and I am not the only one to have this issue.

Save and reboot

WordPress Themes