Re: poor raidframe performance while setting it up

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sun, Jun 07, 2009 at 10:22:27PM +0200, Bernd Ernesti wrote:
> 
> I checked that first and the counter is still zero.
> A short smart self test doesn't produce any errors either.
> And I also tried to dd to and from both drives at the same time after I
> encountered the performance problem. There were no problem.
> 
> I also swapped both drives, so the faster one is now wd2, but the
> same problem occurs with wd3.

I wonder if this could be some cache effect. To achieve this level of
write performance the drive has to use a write-back cache. I wonder
if it's becomming write-though at some point in the process (this could
be a firmware issue, which tries to "optimise" things)

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--