Most of this blog entry material is taken from “Checking /proc/mounts on remote server” from Nagioswiki . The Nagios version is 3.x and the OS Platform CentOS 5.x

We will basically require 2 Nagios Plugins “check_disk” and “check_nrpe” plugins to use this excellent nrpe plugins

On the Remote Server, install the

# yum install nagios-nrpe nagios-plugins-disk

On the Remote Server, go to nagios configuration file and the command inside nrpe.cfg

# vim /etc/nagios/nrpe.cfg

command[check_disks_proc_mounts]=/usr/lib/nagios/plugins/check_disk -w 15% -c 10% $(for x in $(cat /proc/mounts |awk '{print $2}')\; do echo -n " -p $x "\; done)

On the Nagios Server,

Ensure you have the check_nrpe plugins inside. and test the plugins

# yum install nagios-nrpe
# cd /usr/lib64/nagios/plugins
# ./check_nrpe -H monitored-server -c check_disks_proc_mounts

DISK OK - free space: / 28106 MB (53% inode=98%); /boot 81 MB (86% inode=99%);
/dev/shm 1887 MB (100% inode=99%);| /=24543MB;47188;49964;0;55516
/boot=12MB;83;88;0;98 /dev/shm=0MB;1603;1698;0;1887

Add the following definition in your commands.cfg file

define  command {
        command_name    check_nrpe_disk_procs
        command_line    $USER1$/check_nrpe -H $HOSTNAME$ -c check_disks_proc_mounts -t 20
        }

Add the following sort of host check (assuming, of course, that your host is already in your config)

define service{
        use                    local-service
        host_name              monitored_server
        service_description    check_disk on proc mounts
        check_command          check_nrpe_disk_procs
}

Horray it is done.