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Check NTP Time

Posted: Wed May 11, 2011 5:04 am
by silentnoises
I'm now having a Nagios server in a Linux machine, LinuxMachineA. Currently using Nagios 3.0.3. LinuxMachineA monitors other Linux machines too. One of the services the nagios server in LinuxMachineA is monitoring is NTP Time Offset, and the plugin I'm using is this check_ntp_time plugin found at "http://sourceforge.net/projects/nagiosplug/files/".

When I change other Linux machines' system time, LinuxMachineA has no problem reflecting these NTP time offset changes in nagios.log such as the following:
... NTP;CRITICAL;SOFT;1;NTP CRITICAL: Offset -31.44479656 secs
... NTP;CRITICAL;SOFT;2;NTP CRITICAL: Offset -31.44479656 secs
... NTP;CRITICAL;SOFT;3;NTP CRITICAL: Offset -31.44479656 secs
... NTP;CRITICAL;HARD;4;NTP CRITICAL: Offset -31.44479656 secs

Problem occurs when I change LinuxMachineA's system time, the web interface will not be able to reflect the critical NTP time offset service status properly as CRITICAL. When I checked back the nagios.log, it shows this error: "Warning: A system time change of XXXXXXX (backwards in time) has been detected. Compensating.."

Any explanation on this issue and how can I fix this so that the web console can show up the CRITICAL status?

Thanks in advance.

Re: Check NTP Time

Posted: Wed May 11, 2011 9:24 am
by tonyyarusso
I believe this is related to issue #23, which was fixed in the 3.2.x release branch of Nagios.