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

[Stian Jordet <liste@jordet.net>]

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):

With barrier:

time bash -c 'tar xjf linux-2.6.27.7.tar.bz2 ; sync'

real 9m57.320s
user 0m16.253s
sys 0m2.692s

time bash -c 'rm -rf linux-2.6.27.7 ; sync'

real 4m46.130s
user 0m0.032s
sys 0m1.300s


No barrier: 

bash -c 'tar xjf linux-2.6.27.7.tar.bz2 ; sync'

real 0m57.028s
user 0m15.157s
sys 0m2.632s


time bash -c 'rm -rf linux-2.6.27.7 ; sync'

real 0m1.502s
user 0m0.032s
sys 0m1.436s

### 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


Altough I find it weird that both Michael and Justin does it faster on a
single disk than I do on my beefy hardware raid. But either way, finally
the system works ok, so I'm happy :) Ohh, wait. Justin is using just
the .tar... Well, that didn't really help that much here:

time bash -c 'tar xf linux-2.6.27.7.tar ; sync'

real	0m43.703s
user	0m0.256s
sys	0m3.312s


Thanks!

Regards,
Stian