Hardware environment: RH2285
Only 46G is displayed when excuting 'free' command on Linux system, but actually there are 88G memory intalled on this server.
1) Login the bmc web interface, check the memory status. It shows the total memory capacity is 84G.
2) Check the memory capacity by command: dmidecode –t memory，it is as the same as the capacity showed in BMC.
3) Check the menu.lst file, and find there is a parameter: mem=46080M.
4) This parameter was modified by someone manually, the memory capacity become normal after delete it.
Grub parameter was modified manually, and this parameter limited the memory capacity of the system.
Delete the grub parameter 'mem=46080M'.