Archived Content

This page has been archived. The information on this page is no longer maintained by Guru Labs. It is provided purely for its historical value to the curious.


Ext3 vs Reiserfs
Or how we got distracted while installing the new mail server...

 July, 11 2002

Our existing mail server, a Cobalt Raq3 running Red Hat Linux 7.1 started having hardware problems and needed to be replaced. This prompted discussion on if we should continue to use qmail, or migrate to Postfix (now included with Red Hat Linux 7.3, our Linux distro of choice (and yes, we've used them all, including Gentoo). Another decision to make was what filesystem to use. We decided to stick with filesystems included with the stable kernel, so that meant either ext3 or reiserfs. This required some benchmarking to settle the question.

It is a little know fact that Red Hat Linux 7.2 and above can be installed using reiserfs by passing the reiserfs option at the initial installation prompt. In Disk Druid, reiserfs becomes a selectable filesystem type. This makes installing with reiserfs an easy task.

Hardware Specs:
  • Dell PowerEdge 1650
  • Intel Pentium III 1133MHz 512 KB L2 cache
  • 768MB 133MHz ECC SDRAM
  • 3 x 18GB 15K RPM Ultra160 SCSI in HW RAID5
  • PERC 3/Di RAID Controller with 128MB battery backed cache
Filesystem Layout:

In each case the filesystems were laid out in the same fashion.

Filesystem            Size  Used Avail Use% Mounted on
/dev/sda5              30G  1.2G   27G   4% /
/dev/sda1              76M  9.2M   62M  13% /boot
/dev/sda2             1.4G   59M  1.3G   5% /var
Journaling Considerations:

The ext3 filesystem has three different journaling modes. The default is ordered and is more conservative/safe then most other journaling filesystems. Supposedly the writeback mode is more akin to what other journaling filesystems such as reiserfs use. According to the man page for mount, "This is rumored to be the highest-throughput option". We plan to dispel the rumor, maybe we should submit a patch for the man page when we are done.

We tested ext3 in both ordered and writeback modes.

We've heard that the notail option of reiserfs can improve performance, especially with small files.

We tested reiserfs with and without the the notail option.

Software versions:

  • kernel - 2.4.18-5
  • PostMark 1.5c compiled with -O2
  • Graphs generated with OpenOffice 1.0 Calc
Next - PostMark

"A man is but a product of his thoughts; what he thinks, that he becomes."
- Mohandas K. Gandhi

All trademarks used are properties of their respective owner.
Copyright © 2003 by Guru Labs, L.C., All rights reserved.