Re: poor raidframe performance while setting it up

[Matthew Mondor <mm_lists%pulsar-zone.net@localhost>]

On Sun, 7 Jun 2009 21:12:18 +0200
Bernd Ernesti <netbsd%lists.veego.de@localhost> 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.
> The slow down happens after a few seonds till 2-3 minutes.

Sorry if this is too obvious, but it's worth making sure of; smart
statistics for both drives show no reallocated sectors?  I've seen
performance drop a lot in those cases, even though the drives continued
to work temporarily (but need fast replacement), and I'd assume raid
would have to slow down at the speed of the slowest drive in most
cases.  Of course, performance would also drop somewhere when using
the disk without raidframe.

Also, no interesting messages in dmesg like autocorrected software
errors or the like?

The name of the controller might also help if a known problem exists
with a particular device or driver...  Some controllers also have
performance problems when operating on more than one device (although
this performance drop appears dramatic).

Thanks,
-- 
Matt