Nagios Support Forum

OH, so you have core 4 from source, and core 3.5 from rpm. I would highly suggest removing the core 3.5 rpm, then reinstalling (not upgrading) from scratch, short of plugins and configurations, you want to keep those and put them back in /usr/local/nagios/...

Thankyou, but i dont have any idea how to reinstall the core without upgrading it . i am a very new user of terminal and linux so please be kind in writing instructions.
i followed this step by step procedure to install nagios http://www.tecmint.com/install-nagios-in-linux/ and for upgrading it http://nagios.sourceforge.net/docs/3_0/upgrading.html
i will be very thankful to you
have a nice day and weekend

First of all, back up your /usr/local/nagios/etc/ directory with the following:
run as the root user.

Then you should be able to run something like "yum remove nagios*" to uninstall the one that you installed via rpm. The actual name of the program might change depending on how it was installed initially so we include the * character to handle variations. Note that this will also remove the plugins.

Then you can safely remove the nagios directory with the following:
again run as the root user.

From here you should have a mostly clean system and you can follow the install directions here:

http://assets.nagios.com/downloads/nagi ... Source.pdf

If you can afford to do so, a clean CentOS 6.5 install might not be a bad idea to make sure we have a known good base to install onto.

Thanks a lot .
i followed the procedure but i see that files and folders from old nagios are still there, and for me (begginer) its a a very complicated situation to diagnose and act .
my final option would be to uninstall everything including the OS, and reinstalling everything, but htis would be the final option because otherwise i will have to go through all the pain again :p
if there is any diagnosing procedure share please.

Please do not bump your questions, it creates needless clutter, and it also puts you lower on our "to be replied to list..."

i followed the procedure but i see that files and folders from old nagios are still there

What files and folders? If you ran 'rm -rf' against the nagios directory, they would be removed. Your nagios directory is /usr/local/nagios is it not?

sorry my misconfusion, you are right i have only single nagios instance , but the problem is i cant access the webpage.

error:404 not found

anyway i note that httpd service is not starting

furqan wrote:anyway i note that httpd service is not starting

That will definitely be part of the problems. What is the full output when you try to restart the httpd process?