How to start ncpa (Nagios) service - Linux

How to start ncpa (Nagios) service:

The Nagios server will communicate with the host when the Nagios agent/service running on the client server.

If the service is not running then the Nagios server will not be able to communicate with the host, in that case we may need to restart the Nagios service. How to do that?

Here are the steps:

1. nagios_listener service will be responsible for communication.

   Check whether that service is running or not by using systemctl or ps -ef command.

or 

[root@cloud home]# ps -ef |grep -i ncpa

2. If the service is not running then restart it.

[root@cloud home]# systemctl restart ncpa_listener

3. Verify the status of the service by below commands:

or

4. To make this service to be started automatically after server reboot:

4.1 check the chkconfig output:

the ncpa_listener is showing "off" for all run levels.

4.2 Make status of ncpa_listener as "on" so it can start after run level 3

[root@cloud home]# chkconfig ncpa_listener on

4.3 Verify the status:

The ncpa_listener is having "on" value for run level 3, 4 and 5.

Note : Please read more about run levels.

So by following above steps we can restart the ncpa_listener service and make it start automatically after server reboot.

Regards,
Kiran Babu Jadhav