On Fri, Aug 31, 2007 at 02:05:12PM +0200, Stuart Brooks wrote:
> I initially reproduced it using the non-buffered interfaces (rwd1g):
> 
> dd if=/dev/zero of=/dev/rwd1g seek=105600 bs=1024k count=1000
> 
> 
> I then tried to reproduce by using rwd1d which initially did't cause the 
> problem:
> 
> dd if=/dev/zero of=/dev/rwd1d seek=131000 bs=1024k count=1000
> 
> 
> But then modified the block size (in case it was a boundary condition) and 
> the problem occurred again:
> 
> dd if=/dev/zero of=/dev/rwd1d seek=134200 bs=1000k count=1000

It probably has a boundary condition. With this, I can see the kind
of firmware bug that could lead to the data corruption you've seen
(an internal counter wrapping).

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