iotop – simple top-like I/O monitor for Linux
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.