Why is my RAM not being recognized on my x86, Itanium or AMD64 system?

Sometimes, the kernel does not recognize all of your memory (RAM). You can check this with the cat /proc/meminfo command.

Find out if the displayed quantity is the same as the known amount of RAM in your system. If they are not equal, add the following line to the /boot/grub/grub.conf:

mem=xxM

Replace xx with the amount o...