Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

My disk often is utilized, but top (and htop, a custom replacement) show nothing suspicious.

Is there a way to sort processes by I/O (more specific: disk) utilization?

Found out using iotop that those strange processes are flush-8:16 and jbd2/sdb3-7. Seems to have to do with usual filesystem operations.

share|improve this question
If I'm correct flush and jbd concerns the sync of the journal (FS metadata) to the disk. Which means you must have some processes either writing to the disk or reading a lot of data and you have the atime option on your mount. I don't recommend this because some software relies on it (mutt and I have heard one backup tool) but you can set your mount to relatime or even "better" noatime. The latter will completely stop updating the access time (which incures a disk write) each time a file is read. – Huygens Jul 27 '12 at 21:48
up vote 33 down vote accepted

Have you tried iotop ?

You may need to install it before. Also, it depends on a kernel feature that may or may not enabled in your specific distribution.

share|improve this answer
Great! Thank you! – Mar 2 '10 at 16:22
Works on Mac OS X, too. Not sure that it is going to help with the problem at hand, though. – dmckee Mar 2 '10 at 16:27
wow. That's fantastic. 15+ years of admin work and I've never run into that. Thanks! – skarface Mar 2 '10 at 17:06
Root access needed, FYI. – Paul Draper Jan 24 '15 at 17:27

You might want to give atop a try. It seems to do a good job of letting you know what is going on.

share|improve this answer
Seems to be better than iotop because it also shows IO busy percent. – sorin Mar 18 '14 at 13:36

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .