We are also facing this problem. Simple test: su -s /bin/sh -c 'echo "Hello"' nobody Hello su: User not known to the underlying authentication module -- Oriol Mula Valls Institut Català de Ciències del Clima (IC3) Doctor Trueta 203 - 08005 Barcelona Tel: +34 93 567 99 77 http://www.ic3.cat http://ic3.cat/wikicfu