64 bit - How do I know if I am running 32 or 64-bit Linux? - Server Fault
Just to confuse things, you can run a 64bit kernel with a 32bit userland, which is what I'm doing. In this case, uname -m returns x86_64 but I don't have any 64bit libraries installed so most 64bit programs won't run. So once you check uname, you need to ...