Ubuntu: tool for displaying disk activity in general and by process

Question

My Ubuntu system is occasionally becoming very sluggish. I'm running many things simultaneously and it's very difficult to tell which program is the culprit.

I suspect that the sluggishness is due to disk activity since the CPU usage is consistently under 50% on each of the 4 cores of the CPU, and over 30% of the 6GB of RAM are free.

Is there a tool that can show me in real time the number of disk IO operations per second and the amount of data read/written per second? Can all this info be broken down and displayed per process?

Answer 1

Try atop. Start it and press d to show disk-related output.

Answer 2

I can recommend iotop, which shows you exactly disk-read and disk-write in bytes per seconds, per process. You can install it with sudo apt-get install iotop in Ubuntu.