Dual Opteron 248s w/ 8GB RAM on Tyan K8W (S2885)

[Bryan Stillwell <bryans@aspsys.com>]

I am having a problem with getting 8GB of RAM to work with the 2.6.5
kernel that Red Hat uses in their new Fedora Core 2 test3 release.  Yes,
not vanilla, but hopefully close enough (otherwise I can try it with a
custom kernel).  The systems (I'm testing on two mostly identical
systems) that are experiencing the problem have these specs:

Motherboard: Tyan K8W (S2885)
Processors: 2 x Opteron 248
Memory: 8 x 1GB
BIOS version: 1.02 (2-3-2004 - latest available)
SCSI card: Adaptec 29320

About 80% of the time I get this error when booting:

...
RAMDISK: Compressed image found at block 0
crc error
VFS: Cannot open root device "<NULL>" or unknown-block(3,2)
Please append a correct "root=" boot option
Kernel panic: VFS: Unable to mount root fs on unknown-block(3,2)


The other 20% of the time it boots up fine, but that's not enough
consistency for these computers final task (beowulf compute nodes).
Also I haven't really stressed the kernel on these boots.

The systems seem to work fine if I pull out half the memory so that they
only has 4GB of RAM.  I've also tested a similar setup using a Rioworks
Arima HDAMA board with 8GB of RAM and it worked.  So I'm led to believe
that this is some kind of driver issue or possibly a bios problem...

Any help/ideas are of course appreciated.

Thanks,
Bryan

-- 
Aspen Systems, Inc.    | http://www.aspsys.com/
Production Engineer    | Phone: (303)431-4606
bryans@aspsys.com      | Fax:   (303)431-7196