This is for Novice Linux Admins who is looking for a way to access > 4gb ram on Linux 32 bit Machines. By default 32bit architecture has limitation of 4gb memory access, by either switching to 64bit os or using PAE kernel you can access > 4gb physical memory.
PAE (Physical Address Extension) kernel is available on almost every distro.
On Fedora / RHEL / CentOS
yum install kernel-PAE
On Ubuntu
apt-get install linux-generic-pae
Once you have kernel-pae installed, you can access memory upto 64gb.