On Jan 2, 2013, at 19:27, "James B. Byrne" <byrnejb at harte-lyne.ca> wrote: > I do that as well. However, I run one on each host just to serve its > own guests and configure the host to run off our central ntp server. Unfortunately, before our upstream vendor's OS release 6, ntp.conf listed several loopback addresses by default. These allowed a confused ntpd to basically marry its siblings and eventually crossbreed itself to a fairly stange state. But it will report ntpd as active, which is why the Nagios check "chek_ntp_)time" actually compares the time to a known good upstream NTP service. >>> 4. On each guest have a cron job that checks for ntpd at regular >>> intervals which reports failures and restarts the time service as >>> necessary. We use: >>> JOBNAME="Check ntpd status and restart if required" ; \ >>> ntpstat > /dev/null && \ >>> if [[ $? -gt 0 ]]; then /sbin/service ntpd start; fi >> Why not configure the ntpd daemon and stick with that? >> It does update on its own [1]. And ntpstat prints out the interval, >> which matches the one mentioned at [1]. >> I don't believe the ntpstat script/job is necessary (I've never had to >> do more than set ntpd to run after configuring the servers it should >> poll). See above. The 'check_ntp_time' tool is much more flexible and complete. itten does work. It's part of the "nagios-plugions-ntp" package, available from EPEL and RPMforge.