http://www.cromwell-intl.com/unix/linux-break-in-howto.html On RHEL 6.2-based systems (like Scientific Linux 6.2): edit /etc/sysconfig/init # Set to '/sbin/sulogin' to prompt for password on single-user mode # Set to '/sbin/sushell' otherwise Like this: SINGLE=/sbin/sulogin Then if you add an 's' to the …