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.

  • 1
    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
  • serverfault.com/questions/25032/… – qwr Jul 5 '19 at 21:44

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.

| improve this answer | |
  • 1
    Works on Mac OS X, too. Not sure that it is going to help with the problem at hand, though. – dmckee --- ex-moderator kitten Mar 2 '10 at 16:27
  • 3
    wow. That's fantastic. 15+ years of admin work and I've never run into that. Thanks! – skarface Mar 2 '10 at 17:06
  • 2
    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.

| improve this answer | |
  • 1
    Seems to be better than iotop because it also shows IO busy percent. – sorin Mar 18 '14 at 13:36
  • 1
    Also no root or suid needed. – Rolf Feb 25 '18 at 21:08

iostat is still the king of detailed I/O information.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.