Re: raidframe and ffs block size interaction

[Stephen Borrill <netbsd%precedence.co.uk@localhost>]

On Fri, 7 Oct 2011, Matthias Scheler wrote:
> On Tue, Sep 27, 2011 at 02:19:56PM -0500, Jonathan A. Kollasch wrote:
> > How do you get maximum performance out of a RAID-1 raid(1) and still use
> > 2KiB or 4KiB FFS frag sizes?
>
> I've benchmark this a while back. You can find my results here:
>
> http://zhadum.org.uk/2008/07/25/raid-and-file-system-performance-tuning/
>
> In short:
> I got the best performance with 128 sectors per stripe unit, a frag-size
> of 2KB and a blocksize of 166KB I'm using these settings to this day
> and the RAID performane of my NetBSD server is good.

For comparison, here are the results using bonnie for a 3, 4 and 5 disk 
RAID 5 with disks that have 4096 byte sectors:

http://www.netbsd.org/~sborrill/RAIDspeed.pdf

--
Stephen