A few commands to see what bit you are running -bash-4.1# arch x86_64 -bash-4.1# uname -a -bash-4.1# file /sbin/init/sbin/init: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.18, stripped