Hi, Like we have only P4 server which supporting up to 20 thin clients
I did a lot of tricks to get Edubuntu working including sound! So I had the issues that a user gnome session doesn't get cleaned up after a user logged out ... For that I wrote the program gnome-watchdog which is working up to now with Feisty ( with deacticated ldm encryption LDM_DIRECTX = True) You can download this package from here: www.morokeni.ch/edubuntu/gnome-watchdog_0.9.2_i386.deb I hope it's useful. For more information about the package see below ... Philipp ---------------------------------------------------------------------------------------------------- gnome-watchdog - cleans up gnome user session of Edubuntu and checks if a user is logged in already. ---------------------------------------------------------------------------------------------------- It happens with Edubuntu that user processes continue to live even though the user is not logged in anymore. This is not a really nice thing because these zombie processes running in the background consume memory and cpu from the server. Now the question is, how can we get rid of this processes? Let us have a look at the current situation: There are different use cases which cause these user zombie processes: (1) Users are lazy. Instead of logging out properly, they just press the power button (hard reset) (2) The user is using CTRL-ALT-BACKSPACE (killing the X11 session) to log out. (3) User is logged out normally but some faulty program does not get terminated. (4) A program is freezing the thin client completely which forces the user to reboot the thin client. (5) In some cases it can even be that these remaining processes prevent a user login with the same user. These scripts ensure that a faulty gnome user session gets cleaned up when a user isn't logged in anymore ... How does it work: During a gnome login process a watchdog script (called gnome-watchdog) starts. The special thing about this script is that it starts with the command nohup. In this way the gnome-watchdog script ignores any hangup signals. This means this script survives even if the user is logging out in the normal way (3) or unexpectedly (1,2,4+5). Basically the script is waiting in a loop until the process gnome-panel gets terminated. In case this happens, he waits a certain period to be sure that the process doesn't get restarted by his parent process. If this does not happen the script assumes that the user is not logged in anymore. Now the cleaning process takes place. The scripts checks if any user processes under this user id are still running. If yes, he kills all these user processes. Based of some testing with these methods you should get 99% of the cases 2 and 3 solved. Unfortunately, if the user is doing a hard reset (1) it will happen that almost all processes including the gnome-panel process will run as zombie processes. Sometimes it happens that after a while, the gnome-panel gets terminated. This will cause the remaining processes to get killed by the watchdog script. When the process gnome-panel of this user survives, it can happen that the same user will not be able to login anymore (5). Now these scripts will also have a solution but it must be manually activated. For this just create the file like this: touch /etc/check_previous_login When this feature is activated, the script gnome-watchdog-start will check during a user login if a gnome-panel is already running. If yes, the user will be notified by a message box that a previous session is still running. The user has now the option to kill this previous session before he logs in. These facts may also be important to know: - All actions from the scripts get logged to the syslog daemon (/var/log/messages). - The script does not get executed for user root, schoolnet and teacher (see script). - The script will only get started when you choose gnome as a session and when you are doing a thin client login. Please note that these scripts have only been tested for a few weeks. Until now we have had good experiences with them. However be warned that they may still have some faults. If you use them and your system and your server start to kill users without notice perhaps it is better to remove them before doing further troubleshooting. -- SchoolNet NA - Youth Empowerment through Information and Communication Technology SchoolNet Namibia provides sustainable, low cost technology solutions and internet access, as well as technical support, training services and rich educational content to schools, community-based educational organisations, and educational practitioners throughout Namibia. www.schoolnet.na toll free number: 0800 005793 -- edubuntu-users mailing list edubuntu-users@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/edubuntu-users
