Re: XFS filessystem for Datawarehousing

makulev(at)gmx(dot)net ("Milen Kulev") writes:
> I am pretty exited whether XFS will clearly outpertform ETX3 (no
> default setups for both are planned !). I am not sure whether is it
> worth to include JFS in comparison too ...

I did some benchmarking about 2 years ago, and found that JFS was a
few percent faster than XFS which was a few percent faster than ext3,
on a "huge amounts of writes" workload.

That the difference was only a few percent made us draw the conclusion
that FS performance was fairly much irrelevant. It is of *vastly*
more importance whether the filesystem will survive power outages and
the like, and, actually, Linux hasn't fared as well with that as I'd
like. :-(

The differences are small enough that what you should *actually* test
for is NOT PERFORMANCE.

You should instead test for reliability.

- Turn off the power when the DB is under load, and see how well it
survives.

- Pull the fibrechannel cable, and see if the filesystem (and
database) survives when under load.

If you find that XFS is 4% faster, that's likely a *terrible*
trade-off if it only survives power outage half as often as (say)
ext3.
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