ad0 READ_DMA TIMEOUT errors on install of 7.0-RELEASE

[Gianni]

On 25/mar/08, at 09:44, Jeremy Chadwick wrote:
>
> I re-read your mail -- sorry.  You're using SATA.
>
> I'll update my Wiki page to state that the loader.conf DMA disable  
> trick
> only works for PATA.
>
> In the interim, I recommend you contact Scott Long, especially if your
> problem is easily repeatable.  He's offered to help track this down.

Thanks I'll try contacting Scott.

In the meantime I think I have narrowed down the problem in my case to  
the on-board Promise SATA controller.
My motherboard has 2 SATA controllers, one Promise and one Via and I  
have 2 sets of disks with gmirror RAID 1 - 2xSeagate Barracuda +  
2xWD5000YS.
atapci0: <Promise PDC20378 SATA150 controller>
atapci1: <VIA 6420 SATA150 controller>

The Western Digital disks were connected to the Promise controller and  
giving the READ_DMA TIMEOUT errors, I've now swapped the disks around  
so the Seagate ones are attached to the Promise controller and now  
these are reporting the errors.
So it seems I can definitely exclude disk hardware problems.
-Gianni