Command explanations --enable-dns: This switch allows realms to be resolved using the DNS server. mv /bin/login /bin/login.shadow cp /usr/sbin/login.krb5 /bin/login mv /usr/bin/ksu /bin Preserves Shadow's login command, moves ksu and login to the /bin directory. mv /usr/lib/* /lib mv /usr/lib/* /lib mv /usr/lib/* /lib mv /usr/lib/* /lib mv /usr/lib/* /lib ln -sf ../../lib/ /usr/lib ln -sf ../../lib/ /usr/lib ln -sf ../../lib/ /usr/lib ln -sf ../../lib/ /usr/lib ln -sf ../../lib/ /usr/lib The login and ksu programs are linked against these libraries. We move these libraries to /lib to allow logins without mounting /usr.