在Nagios的默认配置文件下是没有Linux的配置文件所以如果是用于监控Linux主机，需要自行定义写配置文件，在此就用简单的写了一个Linux下使用的模板：
[root@linuxidc nagios]# vim objects/linux.cfg
define host{
use linux-server
host_name linuxhost
alias My linux Server
address 192.168.218.129 ;这里填被监控主机的IP
}
define service{
use generic-service
host_name linuxhost
service_description CHECK_USERS
check_command check_nrpe!check_users
}
define service{
use generic-service
host_name linuxhost
service_description CHECK_LOAD
check_command check_nrpe!check_load
}
define service{
use generic-service
host_name linuxhost
service_description CHECK_SDA1
check_command check_nrpe!check_sda1
}
define service{
use generic-service
host_name linuxhost
service_description CHECK_ZOMBIE_PROCS
check_command check_nrpe!check_zombie_procs
}
define service{
use generic-service
host_name linuxhost
service_description CHECK_TOTAL_PROCS
check_command check_nrpe!check_total_procs
}
[root@linuxidc nagios]# chown nagios:nagios linux.cfg#修改下配置文件的属组
在linux.cfg配置文件修改好后还需要 在nagios.cfg添加环境变量：
[root@linuxidc nagios]# vim nagios.cfg
…略…
cfg_file=/etc/nagios/objects/linux.cfg
…略…
正在修改后可以用Nagios的配置文件验证检查
[root@linuxidc nagios]# /usr/local/nagios/bin/nagios -v /etc/nagios/nagios.cfg
Nagios Core 4.3.1
Copyright (c) 2009-present Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
Last Modified: 02-23-2017
License: GPL
Website: https://www.nagios.org
Reading configuration data...
Read main config file okay...
Read object config files okay...
Running pre-flight check on configuration data...
Checking objects...
Checked 13 services.
Checked 2 hosts.
Checked 1 host groups.
Checked 0 service groups.
Checked 1 contacts.
Checked 1 contact groups.
Checked 25 commands.
Checked 5 time periods.
Checked 0 host escalations.
Checked 0 service escalations.
Checking for circular paths...
Checked 2 hosts
Checked 0 service dependencies
Checked 0 host dependencies
Checked 5 timeperiods
Checking global event handlers...
Checking obsessive compulsive processor commands...
Checking misc settings...
Total Warnings: 0
Total Errors: 0
Things look okay - No serious problems were detected during the pre-flight check
[root@linuxidc nagios]# /etc/init.d/nagios restart