老师，我从网上下载的。。。真的没思路啊。。

cd /usr/local/nagios/libexec/
vim  check_vm
写入
#!/bin/bash
# check memory script
# Total memory 
TOTAL=`free -m | head -2 |tail -1 |gawk '{print $2}'`
# Free memory 
FREE=`free -m | head -2 |tail -1 |gawk '{print $4}'`
# to calculate free percent
# use the expression  free * 100 / total
FREETMP=`expr $FREE \* 100`
PERCENT=`expr $FREETMP / $TOTAL`
echo "$FREE MB ($PERCENT%) Free Memory"
exit 0

chmod +x check_vm

cd /usr/local/nagios/etc/objects
vim command
写入
define command{
        command_name    check_nrpe
        command_line    $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
        }
 

vim services.cfg
define service{
        host_name               mysql
        service_description     check_vm
        check_command           check_nrpe！check_mem！192.168.111.3
        max_check_attempts      3
        normal_check_interval   2
        retry_check_interval    1
        check_period            24x7
        notification_period     24x7
        notification_options    w,u,c,r
        }

重启服务

service nsgios restart