How to find the process which is cosuming the most i/o in linux?

Question

When I use top the iowait on the host is really high.

iostat tells me which disk is utilized more but I want to find out which process is the culprit?

I am trying to find this out on a red hat linux host. Any suggestions.

EDIT: My linux flavor does not either have atop or ntop and since building kernel is not an option for me don't ask me why :) (since this is not my personal box). are there any other alternatives

Answer 1

I usually use atop. There's a really good article at Debian Package A Day about it. It does require kernel patching (although Ubuntu already has the patch applied, I'm not sure about any other distributions.)

Answer 2

Use iotop.

Or you can get it standalone, it's a simple python script which requires a recent kernel (can't remember, but at least > 2.6.20)