I recently upgraded the RAM in a Dell T610 Server from 32GB to 96GB and when I run a freemem or /cat/meminfo is still shows the original RAM amount. I already:
1. installed all Redhat system and kernel updates.
2. Updated the Grub.conf file to reflect the new memory size.
3. Applied all firmware and bios updates.
4. The BIOS does recognize and passes the memory test.
5. The memory type is Dell original RAM and compatible.
6. Redhat 5.6 supposed to recognize upto 1TB.