REQUIREMENTS PRE-INSTALL POST-INSTALL Create the necessary user 'ntp' and its group 'ntp'. groupadd ntp useradd -g ntp -d /var/empty -s /bin/false ntp passwd -l ntp MISCELLANEOUS Have a look at the start/stop script if you don't like ntpd setting the time immediately at startup. That allows for a large time correction. Disable that feature by removing the '-s' option.