Ok, here's the deal. We just put in two 2gb DIMMS (4gb total) in our dual opteron server. It is on the list of compatible ram types.

We have been trying to install Fedora Core 2 on the machine, it worked before we put in the new RAM. (we used to have 2 1gb chips to give us 2gb total).

It is very important we get at least 4GB of ram to work in the system since it is used to create files as large as or larger then 4GB (fortran programs for physics department at a university).

I'm just wondering if anyone has a clue as to why we cannot install Fedora Core 2 (or Mandrake 64) on the machine. I've passed the option to the Kernel before installing to tell it how much ram we have in the system too!

I'm just very confused and any help would be greatly appreciated.

Did it work with 2GB? What error messages did you encounter? Is the kernel built with high memory support (4GB or 64GB)?


Håkan

Well, it works fine with the 2 GB of memory, no problems.

WHen I try to install fedora. The first time, when it was going into grub, all it did was display 9's for a while then froze. All the times afterward it just shows a single underscore (_) blinking...

When I tried to install mandrake, it just freezes at various points...

I'm not sure how to check if the kernel is built with high enough memory support. The only thing I've done is pass "linux mem=3967M" (which is the exact amount of memory in the system). When I do that, I get an error that says "size and base must be multiples of 4kb" but it goes into setup anyway.

The strangest thing about it, is that the apaptec raid card we have (ASC-2200S) is not detected when we have the 4GB of memory installed.

I thought it might be that one of the chips of ram was bad, so I booted each individually with the system, and they had no errors. I only get errors when they are used together.

I have a couple more things to try: first, installing windows xp, because it should detect the 4GB of ram. Then, trying 4GB of ram across 4 1GB chips.

If anyone can think of anything else I would greatly appreciate it.

Thanks,
Justin.

This is a stupid question (disclaimer) Have you tried just 1 of the 2 gig sticks? Also, have you tried 1 - 2 gig stick and then tried with the other 2 gig stick without them both in? I've had ram bad from the factory, that's why I ask. Hope that helps!

Travis

What motherboard model and brand are you using. If its a Tyan motherboard, someone had problems with dual Opteron motherboards when they are upgrading to 4 GB of memory. After they flashed the BIOS, everything worked perfectly.

I thought 4096 megabytes equals 4 GB.

I figured it out, there is a problem with the AACRAID driver for 64-bit processors when you hit the 2GB mark for ram. It is mentioned somewhere in bugzilla on redhat's website, and it took me hours of digging to find it out. Basically, it is a strange bug that no one can figure out, and it only effects some Raid cards. To solve this I set the mem=3900M during install and then during boot in grub, after that the system works fine. I hope the fedora community, adaptec, and redhat gets this figured out soon, they should since this is still "bleeding edge" stuff I am working with.

exampe for any one else with the problem:

put this before you boot for installation: linux mem=3900M

and edit your /boot/grub/grub.conf and add the mem=3900M statement, like this:

title Fedora Core (2.4.22-1.2115.nptl)
root (hd0,1)
kernel /vmlinuz-2.4.22-1.2115.nptl ro root=LABEL=/ hdc=ide-scsi mem=3900M rhgb
initrd /initrd-2.4.22-1.2115.nptl.img

Thanks for all your suggestions. And to tbeehler, thanks for the input, I already tried it, but I know that sometimes people just don't think of the simplist stuff to try to test stuff out.