On Thu, Feb 16, 2012 at 9:34 AM, Alex Schuster <wo...@wonkology.org> wrote: > Mark Knecht writes: > >> On Thu, Feb 16, 2012 at 7:29 AM, Alex Schuster <wo...@wonkology.org> >> wrote: > >> > How can I find out in such a case which processes are waiting >> > for I/O? top showed nothing. >> >> iotop is your friend. > > I had called it, but didn't spot the problem there. I don't remember > exactly what the output was, I had expected to see some process show a > large value in the IO column, but that was not the case. I THINK! Various > processes appeared, mostly Akonadi stuff. > > I should have logged this, I don't remember this s well. I have caught > some illness, and had fever, which did not help my memory. There were > some kworker processes listed on top, but I don't remember whether in > iotop or in top. > > Hmm. Now I just started Akonadi again, and get a lot I/O in iotop, and > xosview again shows much iowait CPU activity for a while. But that calmed > down after a minute. > >> I'll write more when I get some time to think > > Thanks :) > > Wonko >
Sorry. I was rushing then as now. If you start iotop and then hit the 'o' key it will show only processes actually doing io. If you're hang is truly an iowait then my experience is that it should at least identify what process is having the problem. HTH, Mark