Handy Tips and Tricks

The following "Handy Tips and Tricks" can be found below:

  • More than 2 kernels when yum updating
  • Killall AG Script
  • Configuring Remote Desktop (Gnome)

More than 3 kernels when yum updating

By default, when doing yum updates, only 3 kernels remain after the update. Example, current kernel that you are running and the new updated kernel with any existing kernel versions being removed. Sometimes you might want more than 2 kernels, for testing or any other reasons. To enable more kernals, simply edit the following line to the /etc/yum.conf file:


to read



Where the 10 represents the number of maximum number allowed, in the case above, I set the maximum number to 10.

Therefore, the /etc/yum.conf file should look something like:


Killall AG script

There may be times when the AG software “hangs” or it doesn’t shutdown correctly. Therefore, the following script can be used to “kill” Access Grid related processes. This script may also be useful if there are “zombie” AG processes still running which prevent the Venue Client from Starting.

  • Start up "Terminal". Create a file called and edit it. To do this type "vi". You then need to type the following into the file. When you are finished, hit the "esc" key, type ":wq" then hit the enter key to save and exit:

TARGETS="VideoConsumerService VideoProducerService VideoService AudioService rat-4 vic rat VenueClient"

for target in $TARGETS


for p in `ps -ef | grep ${target} | grep -v grep | awk '{ print $2 }'`


kill -KILL $p



  • You then need to change the permissions of the file to make it executable. To do this, execute the command chmod 755
  • To execute this script, simply execute ./

Note, do not use this script to shutdown the Access Grid software normally, because if you are using a multi-node setup and you use this script to shutdown the AG software, node services such a VideoProducers will still be running on other machines that make up the Access Grid node. Additionally, it might be useful to make a shortcut to this script and place it on the desktop.

Configuring Remote Desktop (Gnome)

(Please note that there is a bug that only allows the control on a single X window if using the nvidia drivers. Using the default nouveau divers work without any issues)

Remote desktop is very useful, as it allows you to "vnc" to the desktop and remotely control the display. This is particularly useful when, as a node operator, allows you to remote control the AG. Examples for where this is useful include:

  • starting and shutting down the AG;
  • switching venue;
  • arranging video streams; and
  • many other purposes.

To enable this, simply select “System -> Preferences -> Remote Desktop” from the gnome panel.

Once you have the “Remote Desktop Preferences” windows up, it is recommend to use the following settings:


  • Allow other users to view your desktop (enabled)
  • Allow other users to control you desktop (enabled) [this will allow remote control of desktop]


  • Ask you for confirmation (disabled) [otherwise for control, intervention is required]
  • Required the user to enter a password (recommended so others cannot accidentally log in)

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