This is the full pathname to a script that will be run by smbd 8 when a machine is added to Samba's domain and a Unix account matching the machine's name appended with a "$" does not already exist. This option is very similar to the , and likewise uses the %u substitution for the account name. Do not use the %m substitution. /usr/sbin/adduser -n -g machines -c Machine -d /var/lib/nobody -s /bin/false %u