Suppose I have a large number of processes and one (or more) is IO bound, obvious by a high
wa value in
top. How can I pinpoint which process it is? Each process shows how much cpu is being used, but how can I tell how much that process is causing the OS to wait due to IO?
sudo iotop gives you a nice, top-like overview of all disk io activty like this:
To install, use
sudo apt-get install iotop
$ pidstat -d 5
Should print processes and their disk activity every 5 seconds. Pidstat can be found in the sysstat package.
$ sudo apt-get install sysstat