The MM (Memory Module) displays memory usage, including the size of the system memory, disk cache memory, and memory disk. If the MEMORYCEILING (Set Memory Ceiling) command is set, MM also reports the amount of memory not in use. If the system supports firmware memory locking, MM also reports the memory locking status.
Syntax

Example
MM
MEMORY USAGE: SYSTEM 6192 MWords MEMORY DISK 1000 MWords DISK CACHE 1000 MWords NOT IN USE 8192 MWords (MEMORYCEILING 8192 MWords) TOTAL ONLINE 16 GWords Firmware memory locking is disabled