4GB on M2A-VM HDMI

I upgraded from 2GB to 4GB of DDR2-5300 and the SATA drives
disappeared! It's totally weird
since the the POST memory check finds no errors and the RHEL4 boot
image is loaded into
memory and begins to run. IOW, the drives are found, the GRUB
bootloader loads the data
from the drive partition but the O/S can't see the drive it was loaded
from?!
If I remove the extra 2x1GB sticks it has no problem. I thought it was
a problem with the memory
mapping and upgraded to the latest BIOS version but it didn't work.
Am I missing something obvious?

Thanks in advance!

Sudsy

Sudsy wrote:
> I upgraded from 2GB to 4GB of DDR2-5300 and the SATA drives
> disappeared! It's totally weird
> since the the POST memory check finds no errors and the RHEL4 boot
> image is loaded into
> memory and begins to run. IOW, the drives are found, the GRUB
> bootloader loads the data
> from the drive partition but the O/S can't see the drive it was loaded
> from?!
> If I remove the extra 2x1GB sticks it has no problem. I thought it was
> a problem with the memory
> mapping and upgraded to the latest BIOS version but it didn't work.
> Am I missing something obvious?
>
> Thanks in advance!
>
> Sudsy
>

The Linux kernel has several memory models. 1GB, 1GB-4GB, then up to 64GB.
Would the problem be related to the memory model being used ?

It is called "High memory support" on this page:
http://www.gentoo.org/doc/en/kernel-config.xml

Here, you can see some kernel build options:

http://kerneltrap.org/node/4030

"CONFIG_NOHIGHMEM=y
# CONFIG_HIGHMEM4G is not set
# CONFIG_HIGHMEM64G is not set"

"Got more than a gig of RAM and 32-bit Linux? Here's how to use it"
http://www.linux.com/feature/119287

I don't know if that stuff is applicable to your problem, but you
might want to read up on kernel building, and exactly when changing
those options is needed. Also, an alternative to removing the sticks
of RAM, would be to investigate whether there are any boot time options
to "ignore" part of the physically present RAM. There was a trick
in Win98 to do that, and maybe Linux has some way of doing that too.

Paul

On Oct 27, 1:09 am, Paul <nos...@needed.com> wrote:
<snip>
> I don't know if that stuff is applicable to your problem, but you
> might want to read up on kernel building, and exactly when changing
> those options is needed. Also, an alternative to removing the sticks
> of RAM, would be to investigate whether there are any boot time options
> to "ignore" part of the physically present RAM. There was a trick
> in Win98 to do that, and maybe Linux has some way of doing that too.

Many thanks. It was actually the x86_64 version of RHEL4 which I
installed but your
reply fired off some neurons which might permit me to better focus my
search
efforts. The CPU is an AMD64X2 5400+ which installs the SMP kernel.
Sweet!

BTW, I love the irony of the link to www.linux.com. The page doesn't
display on
Netscape Navigator; it's designed for Internet Exploder!

Sudsy.