SCSI Drives / Large Memory Kernel Panic

[Steven Wagner]

I'm trying to upgrade a server from 2 GB of registered ECC RAM to 4 GB.
The extra RAM was specifically purchased from the manufacturer to be
identical to the existing modules. After installing the extra RAM the
server panic'ed so we tried installing some other kernels, even enabling
huge mem (64 bit) to no avail.

I rebuilt the server with CentOS 4.4 Server CD with all 4 GB of RAM
installed. It panics when I try to boot with the full 4 GB installed,
but boots fine when I remove 2 GB.

The panic seems to happen when the SCSI card driver, aic7xxx, tries to
enable the disc drives. The console error says:

aic7xxx_dump returns 0x2002
Device offlined

then a slew of SCSI I/O errors, the exec of init failed, then the panic.
It seems weird that the card and the drives work fine with the 2 GB of
RAM...Anybody have any thoughts?

TIA,

Steve

BTW, I installed CentOS 4.4 on this machine to a SATA drive and it sees
all 4 GBs and works fine.