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Re: Why Debian3.1 is slower so much than FreeBSD6.1 in our test?

On Friday, 30.06.2006 at 12:11 +0800, Leo Huang wrote:

> >ext3 flushes to disk every 5 seconds by default (see 'commit'
> >interval in 'man mount') which is a safe, conservative setting but
> >might hit performance.
> The data is critical to us, so we must ensure every transaction is not
> lost.

I don't doubt that to be the case, however I was merely suggesting that
the above ext3 setting might be responsible for the difference you see
between Debian/ext3 and FreeBSD/ufs: I can't comment further since I
have no experience of using FreeBSD/ufs.  Since you're interested in
finding out where the performance bottleneck is, you could at least
benchmark the difference (using non-critical data): if, for example,
FreeBSD/ufs flushing data to disk every *20* seconds (I have no idea
what the real value is), that would be part of the explanation of your
problem.  It's certainly worth investigating, if you have the

For what it's worth, it is usually safe to raise the ext3 commit interval on
a system, at least up to the period of time which is covered by UPS
power support.

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