Make sure you have nrpe installed on remote host. Add the new service in /usr/local/nagios/etc/services/my_checks.cfg

1. Example adding of inodes check:

define service{
    use                             generic-service
    hostgroup_name                  monitored-hosts
    service_description             Check system inodes
    check_command                   check_nrpe!check_disk_inodes
    servicegroups                   sysservices
}

2. On server add the script to /usr/local/nagios/libexec/ directory.

3. Add command to nrpe config /usr/local/nagios/etc/nrpe.cfg

...
command[check_disk_inodes]=/usr/local/nagios/libexec/check_disk_inodes
...

4. Reload nagios server and nrpe on remote server.

• Debian 11
• Nagios 4.4.7
• nrpe 3.3.0

• Add new check on localhost (nagios itself)