Re: mpt Serious performance issues

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

On Fri, Jan 28, 2011 at 03:13:10PM +0100, Stephan wrote:
> I found another hint regarding slow mpt performance which was
> discussed for FreeBSD:
> 
> ===================
> Would you be able to take a scsi bus trace to
> see what the negotiated speed over the bus?
> Also would you able to see when the driver
> loads if the PPR(Parallel Protocal Request)
> and WDTR(Wide data tranfer request) were issued
> by the driver to both disk drives. If not, then
> its possible your running at asyn narrow speeds
> on one of the disk, which would be about 5-15 MB/sec.
> 
> Eric Moore
> LSI Logic
> ===================
> 
> I think the idea is what settings the RAID controller has negotiated
> with the disks. Should this be considered also?

I don't think this is under the driver's control. AFAIK the driver only sees
the logical drive, not the physical drives. But it's hard to tell without
detailed documentation ...

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