Re: Linux filesystem speed comparison

Steven Wilton wrote:
> The interesting thing is that this test shows that in a 2.6.10 kernel, XFS
> is the clear winner for I/O wait, followed by ext3 writeback. I was not
> surprised to see reiser come off worse than ext3, as I have previously tried
> to use reiser on our proxies (on a 2.2 kernel), and noticed that initially
> the proxy was a lot quicker, but as the disk filled up, the cache
> performance dropped.
>
> I thought I'd post this to squid-dev for comments first, as I have read
> other posts that say that squid+reiser is the recommended combination, and
> was wondering if there are other tests that I should perform.

The only test I know of that accurately predicts how a proxy will
perform when given real load is Polygraph. And depending on the
hardware configuration, either ext2/ext3 or reiserfs will easily
outperform xfs. In my experience, ReiserFS is a better performer
assuming CPU is not a bottleneck. But it is a much heavier user of CPU,
and so some test results (like Duane's extensive benchmarks from a year
or more ago) show ext2/3 performing measurably better than ReiserFS. A
Polymix-4 test will fill the cache twice and then begin the test...so it
takes into account the decline in performance that hits all filesystems.

It depends on the balance of hardware, but I'd be extremely surprised if
XFS performs better than either reiser or ext2/3 for Squid workloads on
/any/ system. So I have to assume your methodology is slightly flawed.
;-)

While I have found that ext3 (when configured correctly) has improved
performance for Squid quite a bit over ext2, it is still no match for
ReiserFS on our hardware, which always has more than enough CPU for the
disk bandwidth available. But, I can certainly imagine a hardware
configuration that would lead to ext3 performing better than ReiserFS
(especially since Duane has proven that it is possible by putting 6
10,000 RPM disks on a relatively wimpy CPU and testing the configuration
extensively with polygraph).

I'm always interested in conflicting reports, however. If you've got a
case that makes XFS faster for Squid against polygraph, I'd love to see
the results and configuration.
Received on Mon Apr 11 2005 - 15:38:26 MDT