# install PAE kernel. # $ sudo yum install kernel-PAE kernel-PAE-devel
Once I did this, rebooted and you can see the memory is recognised:
# memory shown for 8GB after PAE kernel installed. # $ free total used free Mem: 8154348 5368672 2785676 $ grep MemTotal /proc/meminfo MemTotal: 8154348 kB
Now my Java efforts are rocket fast on this machine!