server diagnostics program for suse 9.1

Hi, I need to get some statistics data/graphs for a LTSP server. For ethernet I will use ethereal, since it provides very good statistics. I would like to know if there is a program that could monitor server cpu/proc/disk load over time (simultaneously with ethereal) and provide statistics (numerical data, graphs). I already have gkrellm, but it just shows current data. Ksysguard offers no statistics data. Thanks