These server notes.ini parameters deal with the allocation of memory for the Lotus Domino server. As mentioned previously, a system running 64-bit Linux can allocate 4 GB of memory to a 32-bit application. The notes.ini parameter MEM_AddressableMemSizeMB=3500 tells Lotus Domino that it has 3.5 GB of memory to use. This statement sounds like a contradiction because we just said that a 32-bit application can get 4 GB of memory. The operating system needs some of this 4 GB for mapping and other memory pools for all the Lotus Domino tasks that are running. Usually 500 MB is ample for this task.