am2 MBs - 4g + SCSI wipes out root partition

Jeremy Chadwick koitsu at
Mon Oct 13 06:57:09 PDT 2008

On Mon, Oct 13, 2008 at 07:39:44AM -0600, Scott Long wrote:
> JoaoBR wrote:
>> On Sunday 12 October 2008 14:10:36 Scott Long wrote:
>>>>> I am using some LSI (mpt driver) ultra4 (U320 scsi) and LSI SAS
>>>>> controllers in FreeBSD 7.x amd64 with 20G of ram, and Adaptec (aac
>>>>> driver) with a 5th generation RAID card with 8G of ram, both have no
>>>>> such corruption problems.  Providing this as a counter-example just to
>>>>> document some evidence of which products seem to work fine.
>>>> Is your LSI SAS controller driven by mpt(4) or mfi(4)?
>>> I can personal vouch for MPT and MFI drivers working just fine with >4GB.
>> let narrow this a little bit, are you talking about AM2 sockets? 
>> because on AM2 the MPT drv is faulty as AHC, AHD and AACD with => 4Gigs
> Sounds to me like this is a problem either with AM2 systems, or an  
> infrastructure problem in the OS that is triggered by these AM2 systems.
> Either way, it's not a SCSI driver problem.

Fully acknowledged.  I'll add an entry to my Wiki describing this
compatibility problem, but it *will not* fall under the SCSI subsection.

It sounds as if there's an implementation/design problem either in
FreeBSD's hardware compatibility support for AM2 (probably something
very low-level) systems, or there is a bug with these Gigabyte boards;
it could be either, or possibly both.  It might work in Linux because,
for all we know, Linux may have workarounds in place for whatever the
problem may be.  We simply do not know at this point.

| Jeremy Chadwick                                jdc at |
| Parodius Networking              |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |

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