I'm not sure why you need 3 Terabytes of RAM in every server. Even if you were to replace every single application on your OS with a JVM based one (including things like bash) you wouldn't meaningfully hit that limit. If you have an application that does indeed need many Terabytes in the same address space then you probably have a very small number of servers. No one runs a 1000 node cluster where each node has 3TB RAM.