Unable to start nagios

[cwang@fielding.edu]

I am new to nagios and try to restart but failed. Any idea would be appreciated.

[root@Nagios bin]# ./nagiostats

Nagios Stats 4.4.3
Copyright (c) 2003-2008 Ethan Galstad (www.nagios.org)
Last Modified: 2019-01-15
License: GPL

Error reading status file '/usr/local/nagios/var/status.dat': No such file or directory
[root@Nagios bin]# ./nagios -d /usr/local/nagios/etc/nagios.cfg
[root@Nagios bin]# ps -ef|grep nagios
nrpe 845 1 0 05:46 ? 00:00:00 /usr/sbin/nrpe -c /etc/nagios/nrpe.cfg -f
root 1471 1311 0 06:18 pts/0 00:00:00 grep --color=auto nagios

[gormank]

On redhat/centos: systemctl start nagios
Check the nagios.log and messages files.
systemctl status nagios