Ram not recognized

So GEEKS. After bringing smiles on your face. Its the time to use some brain.

Geeks, believe me I am facing a strange problem in our lab. We have a dedicated lab for RHCSS / RHCVA training, as these training requires very high end machines. So we have AMD 6 core CPU, with 16 GB of RAM and 1 gig NIC for each student machine.

But this is not the problem.

The problem is when I install RHEL 5x on these machines and run “meminfo” or “cat /proc/cpuinfo” is shows me 16 GB of physical RAM. But …. when I install RHEL 6x on the same machines and run the same command it shows me only 3 GB of physical RAM.

Strange, but true!!

Please tell me what to do, to make kernel recognize the full 16 GB of physical RAM?

PS: Check for students response on Network NUTS Facebook Page.