However, when not using one of the monitors, Gnome does not know what to do with the panel normally displayed on that monitor and places it on the default monitor, resulting in two gnome-panels on one monitor. This is not so useful!

To circumvent this default Gnome behavior use the following procedure:

• Download gnome-panel-switch.sh script and put it somewhere you like:

#!/bin/bash
#
# Auto adjust the number of pannels based on the number of
# connected monitors.
#
# Author : Amain 2010
# Website: blog.zoomeren.nl
 
# Monitor states:
#   - connected 1440x900+0+0  ( connected and used )
#   - connected               ( connected not used )
#   - disconnected            ( disconnected       )
#
NR_OF_MONITORS=$( /usr/bin/xrandr -q | /bin/grep " connected [0-9]\+x[0-9]\+" | /usr/bin/wc -l )
 
# Second panel name
#
# note: retrieve the panel name using gconf-editor
#
SECOND_PANEL_NAME="panel_0"     
 
case $NR_OF_MONITORS in
        1)
                # Disable external monitor ( setting screen to -1 )
                #
                gconftool-2 --type int --set  /apps/panel/toplevels/$SECOND_PANEL_NAME/screen -- -1
        ;;
 
        2)
                # Enable external monitor ( restart is needed after setting screen to -1 )
                #
                gconftool-2 --type int --set  /apps/panel/toplevels/$SECOND_PANEL_NAME/screen 0
                /usr/bin/killall gnome-panel
        ;;
 
        *)
                # no action
        ;;
esac

• sudo chmod +x gnome-panel-switch.sh
• sudo mv /usr/bin/gnome-display-properties /usr/bin/gnome-display-properties.bin
• sudo vi /usr/bin/gnome-display-properties and paste the following script ( don’t forget to adjust the path in line where gnome-panel-switch.sh is called! ):

#!/bin/bash
#
# Auto adjust the number of pannels based on the number of
# connected monitors.
#
# Author : Amain 2010
# Website: blog.zoomeren.nl
 
# Open gnome-display-properties dialog
#
/usr/bin/gnome-display-properties.bin
 
# Auto enable/disable gnome-panels
#
YOURPATH/gnome-panel-switch.sh

• sudo chmod +x /usr/bin/gnome-display-properties
• Start gnome-panel-switch.sh every time Gnome starts to auto disable/enable the correct number of gnome-panels per display. Use Gnome Startup in the System Settings menu and add the invocation for this script.
• Important note: when /usr/bin/gnome-display-properties is replaced during a Ubuntu upgrade one looses the changes!

post-up /usr/sbin/ethtool -s eth0 wol g
post-down /usr/sbin/ethtool -s eth0 wol g

Write down the MAC-ADDRESS. Powerdown the computer. Only when the computer is powered down to S3 or STR(Suspend to ram), the computer can be woken up. A sudden power-failure might mess with everything so the computer might not respond then to WOL requests. For STR some additional action are necessary, because STR in Linux might/will totaly power-off the ethernet device. See this link for more info on that subject.

On another computer install a wake-on-lan package:

dpkg -i wakeonlan

and wake up the sleeping computer:

wakeonlan MAC-ADDRESS

note: create a small shell script in for example ~/bin/wol_dev.sh to make life easier and to not forget the MAC-ADDRESS:

#!/bin/sh
#
# Wake on lan server: dev
#
# dev eth0 00:02:44:57:dc:33
# dev eth1 00:10:4b:0e:ce:13
 
wakeonlan 00:02:44:57:dc:33

That’s all!

Links:

• http://xlife.zuavra.net/index.php/60/
• http://linux-tipps.blogspot.com/2008/11/fixing-wake-on-lan-in-ubuntu-810.html

It seems to be that VirtualBox has a problem switching between multiple core’s on the host and therefore causing high CPU load on the host, even while the Guests are idle. This is of course not good. There are a couple of solutions / workarounds:

1. Adjust the CPU affinity for the Guest’s VirtualBox process
2. Configure multiple CPU’s in the Guest’s VM settings
3. Run another small idle/dummy Guest VM besides the one you want to use

I use the second option with success. I have an Intel(R) Core(TM)2 Duo CPU laptop and I assigned 2 CPU’s in the Guest’s settings and now the host CPU usage is back to normal, luckily. Also note that it’ has been reported, that VirtualBox is not very well handling tickless kernels ( CONFIG_NO_HZ=y ) or has higher CPU usage with high resolution timers like 1000 Hz ( CONFIG_HZ_1000 ). Ubuntu Jaunty has for example a tickless kernel and OEL 5.3 ahs a timer tick of 1000 Hz.

Links:

• http://tech.shantanugoel.com/2009/07/07/virtualbox-high-cpu-usage-problem-solved.html

1. Avalon Compiz Emerald Theme
2. Humanity Gnome Icon Theme
3. Yellow U-Flower background image

Click on the image to enlarge.

Comparing resolution (3040x1200) to maximum 3D texture size (2048): Failed.

I was wondering why. I hoped it not be a hardware limitation. And fortunately it isn’t. At least not in my case. There seems to be a problem in mesa. Before upgrading mesa using a PPA repository where a small patch was applied by the owner of the PPA, my system reported:

glxinfo -l | grep GL_MAX_TEXTURE_SIZE
 GL_MAX_TEXTURE_SIZE = 2048

After:

glxinfo -l | grep GL_MAX_TEXTURE_SIZE
 GL_MAX_TEXTURE_SIZE = 4096

To upgrade mesa, install mesa from the following PPA:

https://edge.launchpad.net/~cavedon/+archive/ppa

The patch seems to be included in Ubuntu Karmic, and is not jet corrected in Jaunty because it was considered a to great a risk at this stage. The PPA mesa packages( libgl1-mesa-dri, libgl1-mesa-glx, libglu1-mesa, mesa-utils ) are working without causing any problems on my system. I now fully enjoy Compiz working on one big desktop with a virtual screen size of 3120×1050.

Links:

• http://ubuntuforums.org/archive/index.php/t-1115208.html
• https://bugs.launchpad.net/ubuntu/+source/mesa/+bug/146298

$HOME.mozilla/firefox/<random>.vmware/extensions/VMwareVMRC@vmware.com/plugins/vmware-vmrc

But no way it would start from the VMWare server webinterface. The solution in my case was simple though: Don’t use a Firefox profile with a space in the name. My profile was called ‘Default User’ and that didn’t work. After creating a new profile ( called vmware ), without spaces, it worked!

• Press CTR-ALT-. ( The . / ALT key on the numeric keyboard )
• On a laptop without numeric keyboard: CTRL-ALT-PrintScrn
  ( note: on my laptop that is: CTRL-ALT-Fn-PrintScrn )
• CTRL-ALT-INS is reported to work but, didn’t work for me
• Using VNC
  • Add the following lines to the VMWare .vmx config file:
    

     RemoteDisplay.vnc.enabled = "TRUE"

     RemoteDisplay.vnc.port = "5900"

     RemoteDisplay.vnc.password = ""

  • Restart Guest OS and connect with vncviewer to the screen of the Guest OS
  • Press F8 and choose from the menu ‘Send CTRL-ALT-DELETE’

There are more options, but these seem to me the best working.