#!/bin/bash
# check memory script
# sunny 2008.2.15

# 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

 

#将上面的内容复制到/usr/local/nagios/libexec/check_mem.sh
#并用chmod a+x check_mem.sh 为这个插件添加执行功能
#在command.cfg中添加一项check_mem的内容如下

# 'check_mem' command definition
define command{
        command_name    check_mem
        command_line    $USER1$/check_mem.sh -H $HOSTADDRESS$
        }

#接下来可以在services.cfg文件中添加了一项内存的监控如下
define service{
        host_name               nagios-server
        service_description     check_mem
        check_command           check_mem
        max_check_attempts      5
        normal_check_interval   3
        retry_check_interval    2
        check_period            24x7
        notification_interval   10
        notification_period     24x7
        notification_options    w,u,c,r
        contact_groups          sagroup
        }

记得最后测试一下配置文件

/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg