9.1-stable: ATI IXP600 AHCI: CAM timeout

[Adam McDougall]

On 05/29/13 10:21, Oliver Fromme wrote:
> Steven Hartland wrote:
>  > Have you checked your sata cables and psu outputs?
>  > 
>  > Both of these could be the underlying cause of poor signalling.
> 
> I can't easily check that because it is a cheap rented
> server in a remote location.
> 
> But I don't believe it is bad cabling or PSU anyway, or
> otherwise the problem would occur intermittently all the
> time if the load on the disks is sufficiently high.
> But it only occurs at tags=3 and above.  At tags=2 it does
> not occur at all, no matter how hard I hammer on the disks.
> 
> At the moment I'm inclined to believe that it is either
> a bug in the HDD firmware or in the controller.  The disks
> aren't exactly new, they're 400 GB Samsung ones that are
> several years old.  I think it's not uncommon to have bugs
> in the NCQ implementation in such disks.
> 
> The only thing that puzzles me is the fact that the problem
> also disappears completely when I reduce the SATA rev from
> II to I, even at tags=32.
> 
> Best regards
>    Oliver
> 
> 

Jeremy Chadwick knows of some hardware faults with IXP600/700,
there may be more information on the freebsd-fs mailing list archives or
if you can discuss with him:

http://docs.freebsd.org/cgi/mid.cgi?20130414194440.GB38338

That email mentions port multipliers but the problems may extend beyond.