[Linux] linux doesn't seem to see added memory

[Gregory Maxwell]

On Sun, Oct 22, 2000 at 12:30:28PM -0700, Warren Pollans wrote:
> Hello,
> 
> I have just added 128MB of memory (Best Buy special) to my linux box

You would do yourself well to run memtest overnight on your system while
returning your memory is easy. Just prudience.

> (400 MHx Celeron) - 196MB total: 64 MB in 1st slot, 128 MB in 2nd - both
> are marked PC100.  The BIOS sees it, but it seems that linux doesn't -
> Gnome:Utilities:SymtemInfo shows about 64 MB Total Memory that is about
> 90-98% used.
> Question:  Do I need to tell linux (RH 6.1) about the memory? Is there
> another tool that will tell me how much memory linux thinks I have?

You might need to add mem=196m to your boot params. 
Try adding mem=196m to your kernel named at the lilo prompt i.e.

lilo: linux mem=196m

if it doesn't boot after that, try a smaller number lime mem=190m

This occures because many BIOSes have problems correctly reporting the
amount of memory >64mb. Newer kernels have more workarounds for such bioses,
if you have not applied the kernel updates for your RH6.1 this could likely
be the issue.

The percent used is a useless number because it includes disk cache which
can be deallocated the instant an application needs the memory. It's better
to open a shell and type free

Look at the +cache entry and that is your free memory.