Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

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

I have an IBM x3650 M4 server (64-bit) running Ubuntu 13.04 Desktop (32-bit). I realize that this is a non-standard setup by it's being driven by other requirements. I am seeing slow file writes accross the board (to HDD, to USB, to network mount). The file writes seem to peek at 1.3Mb/s. The expected speed of my RAID setup is 180Mb/s.

Here's what I tried:

  1. Boot Live Ubuntu 11.10 64-bit. The file writes are as expected, 180Mb/s.
  2. Boot Live Ubuntu 13.04 32-bit. The file writes are slow, 1.3Mb/s.
  3. Boot Live Ubuntu 12.04 LTS 32-bit. The file writes are slow, 1.3Mb/s.
  4. Boot Live Fedora 19 32-bit. The files writes are again as expected, 180Mb/s.

At this point, it looks like something in the Ubuntu 13.04 32-bit kernel is not being configured correctly to work with the IBM hardware. Fedora 32-bit seems to work just fine.

Would anyone happen to know what could be causing this?

share|improve this question
Please list the filesystem (e.g. ext3 or ext4) for each along with the options (e.g. noatime) to make sure you are comparing apples to apples. – HTTP500 Jul 29 '13 at 18:04
I'm sorry, I did not note any of that info. Live CDs were used with default options. – Konstantin Klitenik Jul 29 '13 at 18:10
I suspect that write barriers are being sent where the performance is poor. – HTTP500 Jul 29 '13 at 18:23

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Browse other questions tagged or ask your own question.