Re: poor raidframe performance while setting it up

[Bernd Ernesti <netbsd%lists.veego.de@localhost>]

On Tue, Jun 09, 2009 at 01:21:35PM +0100, Matthias Scheler wrote:
> On Sun, Jun 07, 2009 at 09:12:18PM +0200, Bernd Ernesti wrote:
> > First it seems to be fast with 75MB/s i/o on both drives and then it
> > slows down very dramatically to 2.5MB/s, so the initail would take 100
> > till 200 hours for this 1TB raid set. With 75MB/s it would have taken
> > 3-4 hours.
> 
> What does "dkctl <device> getcache" report?

# dkctl wd2 getcache
/dev/rwd2d: read cache enabled
/dev/rwd2d: write-back cache enabled
/dev/rwd2d: read cache enable is not changeable
/dev/rwd2d: write cache enable is changeable
/dev/rwd2d: cache parameters are not savable
# dkctl wd3 getcache
/dev/rwd3d: read cache enabled
/dev/rwd3d: write-back cache enabled
/dev/rwd3d: read cache enable is not changeable
/dev/rwd3d: write cache enable is changeable
/dev/rwd3d: cache parameters are not savable

I tried to disable the write cache, but the slowdown effect still
happend.

Bernd

P.S. Now that I have setup the raid I can't do more tests.