After install ntp-utils , in utils.pm not write this strings: $PATH_TO_NTPQ = "/usr/sbin/ntpq"; $PATH_TO_NTPDATE = "/usr/sbin/ntpdate"; It is need to do by self hand ps > uname -a Linux myhost 2.6.18-ovz-smp-alt14 #1 SMP Wed May 2 15:41:34 MSD 2007 i686 GNU/Linux Steps to Reproduce: 1. apt-get install [ntp_packages] 2. apt-get install ntp-utils 3. look to file utils.pm
To proper package and component
Cite from nagios/plugins/check_ntp.c: ... * This file contains the check_ntp plugin * * This plugin to check ntp servers independant of any commandline * programs or external libraries. * ...