>прибить демона(ов) и
>rm /usr/local/nagios/var/nagios.lock

/usr/local/nagios/var$ ps -A | grep nag
2757 ?        00:00:00 NetworkManager
2780 ?        00:00:00 NetworkManagerD
3178 ?        00:00:00 x-session-manag

Демона прибил... Лок удалил. Далее

/usr/local/nagios/var$ /etc/init.d/nagios start
Starting nagios:CONFIG ERROR!  Start aborted.  Check your Nagios configuration.

Опять тоже самое :(

nagios.log
[1183938278] Nagios 3.0a5 starting... (PID=2492)
[1183938278] LOG VERSION: 2.0
[1183938278] Finished daemonizing... (New PID=2493)
[1183938572] Caught SIGTERM, shutting down...
[1183938572] Successfully shutdown... (PID=2493)