Linux FC6 with 8GB RAM

wagz · 08-21-2007, 06:15 PM

Hi guys,
I recently installed FC6 on my new Dell 2650, with Dual Xeon 2.4's, 8GB DDR ECC RAM, 5x36.4GB SCSI Hard drives. Now FC6 is only registering 3.6GB of that RAM, in BIOS setup, it say's there is 8192mb which is correct, anyone got any idea's why FC6 isn't registering the 8GB RAM?

Regards,
Wagz

bongo22 · 08-21-2007, 06:28 PM

The stock kernel shipped with FC6 is compiled with support for 4GB RAM, recompile it with support for 64GB RAM.

Electro · 08-21-2007, 06:31 PM

It is the cause of PAE (http://en.wikipedia.org/wiki/Physical_Address_Extension) when a 32-bit OS is trying to use 4 GB or more of memory. With out PAE, 4 GB can be allocated by a 32-bit OS and processor with out virtual memory getting in the way. If you use a 64-bit OS, all 8 GB of RAM will be used. Though Linux is a virtual memory OS, so it will use some memory for system (kernel) related tasks. In the kernel, you have choice of 3GB/1GB, 2GB/2GB, or 1GB/3GB. The kernel documentation has more on this topic.

wagz · 08-21-2007, 08:04 PM

Hi again,

What kernel is it, and how do I recompile it?

Anyone able to do this with me step-by-step?

Regards,

Wagz

syg00 · 08-21-2007, 08:20 PM

Looks like there should be a kernel-pae included; try that.

wagz · 08-21-2007, 08:25 PM

Where do I find the kernel-pae?

wagz · 08-21-2007, 08:51 PM

Ok I got a kernel-pae ( kernel-PAE-devel-2.6.22.2-42...> )

Now where do I put it and will it work?

Regards,

Wagz

syg00 · 08-21-2007, 10:26 PM

No idea, I'm not a Fedora user - however, I would expect an rpm to put it where it was needed. Ask on the Fedora forum.