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

[Stian Jordet]

ti., 25.11.2008 kl. 15.22 -0600, skrev Eric Sandeen:
> Depending on the old system, perhaps its storage did not allow the
> barriers to be honored, so after xfs saw a test barrier write fail at
> mount time, it disabled them ... you'd see a message if that were the
> case, FWIW.

I know those messages, I get them on my old server. But my old
workstation did not disable the barrier...

But I still don't understand this. On my laptop (HP EliteBook 8530w,
very very powerful, but still a laptop, not an eight core, hardware raid
workstation...), I get this (xfs partition):

barrier:

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

real	1m30.855s
user	0m23.265s
sys	0m4.096s

nobarrier:

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

real	0m37.602s
user	0m15.281s
sys	0m4.184s

With no barriers, it's 22s faster than my workstation. That can't be the
way it's supposed to be?

-Stian