On Monday 15 December 2003 09:13, Ragnar Wisloff wrote: > An LTSP installation (Skolelinux, Debian woody based) at a school is > showing som strange problems which I wonder if anyone can help me out > with. From time to time there seems to be a bottleneck in the system > somewhere, my guess is the network. The symptoms are that users get a > black X on a grey background, a sure sign that KDM is not happy. > However, the machines on which this happens work at other times. In the > log I see that kdm logs messages like these:
I have seen this symptom on my network. The black X on a grey background seems to be caused by the server being swamped by runaway processes or by too many requests for processor or disk read/writes, this causes a lock up and the client connection to the server gets broken and because the server is swamped KDM can't restart . Usually, if it is just too many users, when those users log off KDM will restart and present a log on screen. If there are runaway processes however, they stay runaway and KDM will refuse to start even when there are very few users. You need to be looking at 'top' when these things happen to diagnose the cause but I would hazard a guess that runaway processes are the main cause of these symptoms. Although your server spec. may be a little low for 50 concurrent heavy users (java and flash games, mozilla, openoffice etc.). I run about 90 terminals from three servers, each is a dual Athlon 2000+ with 1 gb ram. Most times this copes but at busy times swapping to disk gets too heavy and things clog up so i am just up-grading to 2 gb ram per server. As a rule of thumb, in a school environment I would recommend the following for your servers to have a comfortable time: One 2ghz+ processor per 15 potential concurrent users 1gb ram per processor hard disk should be scsi with 64 bit access spinning at least 10k rpm At least this is what i would be comfortable with at my school. So for your situation another server of dual processor and 2gb ram would make me comfortable, but then you would need a further /home server to prevent the need for syncing etc. hope this has helped regards garry p.s. more detailed description of my setup can be seen at: www.scholarpack.org ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click _____________________________________________________________________ Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: https://lists.sourceforge.net/lists/listinfo/ltsp-discuss For additional LTSP help, try #ltsp channel on irc.freenode.net
