Re: changing raid level?

[Greg Oster <oster%cs.usask.ca@localhost>]

Matthew Mondor writes:
> On Wed, 28 Jan 2009 11:17:22 +0100
> Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
> 
> > On a slow CPU the read+read+compare+write is killing the whole system
> > (mostly the "compare" I think) with 90% of the cpu working on this.
> > A simple read+write is much, much better on such a setup (the system
> > is still useable while doing a raid1 reconstruct). It matters
> > even on a fast CPU, when both disks are able to provide data at 180MB/s.
> > The system is still useable but comptationnal tasks (esp. network
> > encryption) is much, much slower.
> 
> If the problem is CPU usage more than I/O, could a thread running at a
> lower (higher) priority help for this?

Yes... Andrew Doran and I have been chatting about this.. "stay 
tuned" :)

Later...

Greg Oster