Nagios Support Forum

When I attempt apply config, getting:

There was an error while attempting to apply configuration. Error code: 255.
Error: Cannot open main configuration file '/usr/local/nagios/etc/nagios.cfg' for reading!

Checked permissions on the file:

-rw-rw-r-- 1 apache nagios 7816 Feb 13 08:34 /usr/local/nagios/etc/nagios.cfg

This is the same permissions on all of the other files in /usr/local/nagios/etc/

Hi Greg. Those permissions look correct. Out of curiosity what are the permissions on /usr/local/nagios/etc (I'd expect 775 with apache:nagios as the owner and group). Also, which distro are you running?

Hi Jmichaelson,

/usr/local/nagios/etc :

drwxrwxr-x. 8 apache nagios 4096 Feb 13 08:34 etc

We're running RHEL 9.4, and NagiosXI 2024R1.3

Did you change or do something that caused this to start happening (e.g. an upgrade)? Or does it appear to have begun happening out of the blue?

Hmmm. That looks correct as well. It looks like opening the file as a memory mapped file is failing. Alas https://github.com/NagiosEnterprises/na ... red.c#L214 shows that there are plenty of reasons why it could be failing in your case. If you're comfortable doing it, you may want to use the logit call shown in https://github.com/NagiosEnterprises/na ... fig.c#L108, sprinkled liberally in the shared.c function definition of mmap_fopen to log which spot is failing, to better triage what's going on with it. Compile it, install it, check the logs, etc.

This is a dev-nagios box, isn't much used except to test changes before doing on prod. Attempted to rollback a configuration snapshot, and apply config, and this happened, so basically out of the blue. No changes other than a check to be applied, no upgrade attempted.

I will try the logit you suggest, Jason.