Are you stuck with the error ‘Nagios service does not start – error processing object config files’? We can help with fixing it.

Here at Bobcares, we have seen several such Nagios-related errors as part of our Server Management Services for web hosts and online service providers.

Today we’ll take a look at the causes for this error and see the fix.

Steps to reproduce ‘Nagios service does not start – error processing object config files’

Here we are considering an example. For that, first, we run the below command.

service nagios start

As a result, the below message is produced.

From the above message, the following two lines explain the cause of the problem.

Error: Could not find any host matching 'winserver3' (config file '/usr/local/nagios/etc/objects/windows.cfg', starting on line 74)
Error: Failed to expand host list 'winserver1' for service 'NSClient++ Version' (/usr/local/nagios/etc/objects/windows.cfg:74)

Here Nagios is telling us that the definition for the service called NSCient++ Version has the host winserver3 defined. However, it cannot find the host object definition in any of the defined configuration files.

Moreover, it tells the exact line in the config file i.e. 74. In our example it takes to the beginning of the service definition in /usr/local/nagios/etc/objects/windows.cfg

How we resolve ‘Nagios service does not start – error processing object config files’

Our Support Engineers resolve this error by correcting the object definition error that Nagios is complaining about. In the example above, there are two possible solutions:

• Adding a host object called winserver3
• Removing winserver3 from the service definition

How to prevent this Nagios problem

Whenever any changes have been made in the config file, it is good to verify it. Nagios provides a verify command for this purpose.

/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

After running the above command, the output must end with the below contents to confirm that there is no further issue.

Checking global event handlers...
Checking obsessive compulsive processor commands...
Checking misc settings...

Total Warnings: 0
Total Errors: 0

Things look okay - No serious problems were detected during the pre-flight check

[Need any further assistance in fixing Nagios errors? – We are here to help you]

Conclusion

Today, we saw how our Support Engineers reproduce this ‘Nagios service does not start – error processing object config files’ error and provide a solution to our customers.