32-bit on 64-bit: memory usage for multiple processes I'm working on a Linux hosting solution for game server software, however the software in question is 32-bit and I'd be running 64-bit on the host. Now, I know I can run 32-bit apps on a 64-bit host in a 32-bit chroot jail (or a multilib system, but I plan to do the former to keep them segregated in the filesystem), however what happens when all 32-bit apps use over 4GB RAM combined? Say I have three 32-bit game server programs that use 2GB each - what will happen once the first two hit 4GB combined, and will the third be able to run at all? I hoped to get around this by running a 32-bit userland under a 64-bit User Mode Linux kernel, however I learned to my disdain that one cannot run a 32-bit userland under a 64-bit UML kernel. I suppose I could run a 32-bit UML kernel in a 32-bit userland but then I'd be running afoul of the same memory condition and thus might as well be using `chroot` jails anyway?

Each process runs in its own address space, and being 32-bit restricts that address space to about 3GB for each process. The sum of the memory used by 32-bit applications is completely irrelevant. There is nothing to get around.

If this was a problem, chroot jails would not have the slightest chance of helping. They only affect paths to files.