Linux has always been able to show how much I/O was going on (the bi and bo columns of the vmstat 1 command).
Iotop is a Python program with a top like UI used to show of behalf of which process is the I/O going on. It requires Python ? 2.5 and a Linux kernel ? 2.6.20.
wenn man mal schnell wissen will wer der Uebeltaeter ist.
aptitude install iotop