Re: Extreme slowness with xfs [WAS: Re: Slowness with new pc]

Martin Steigerwald
2008-11-26T12:31:02Z

Am Dienstag 25 November 2008 schrieb Stian Jordet:
> ma., 24.11.2008 kl. 19.36 -0600, skrev Eric Sandeen:
> > I don't know if the storage you're on passes barriers or not, but xfs
> > has barriers on by default, while ext3 does not. ext3 will still
> > likely
> > win the "untar a kernel" race, but for a fairer test, make the
> > barrier settings consistent between the two.
>
> As I wrote earlier, the point wasn't to find the fastest fs. That's not
> what I'm looking for. I just want xfs to perform at least as good on my
> new workstation as it did on my six years old other workstation.
>
> Which disabling barriers helped (notice the rm -rf with barriers...
> nobarrier is almost 200 times faster, 10 times faster on the
> unpacking):

[...]

> ### Ext3
>
> time bash -c 'tar xjf linux-2.6.27.7.tar.bz2 ; sync'
>
> real 0m18.663s
> user 0m14.693s
> sys 0m2.828s
>
>
> time bash -c 'rm -r linux-2.6.27.7 ; sync'
> real 0m0.635s
> user 0m0.028s
> sys 0m0.564s

It would be interesting to know the value on Ext3 with barriers.

I wonder whether XFS performance with barriers enabled can be improved?
And whether XFS with disabled write cache (via hdparm) but without
barriers might even be *faster* than XFS with barriers... One thing to
test eventually.

--
Martin 'Helios' Steigerwald - http://www.Lichtvoll.de
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