Once you have installed and configured nagios-client in your Linux system you can easily monitor your LVM on Nagios tool. This LVM space monitoring only for low disk space.

Client configuration:

Download the files from the URL : http://www.lihas.de/anleitungen-und-service/check_vg_size

Move the file to that directory,

#  mv check_vg_size  /usr/local/nagios/libexec/.

# cd /usr/local/nagios/libexec/

To run the file give execute permission and nagios user permission,
 
#  chmod  +x  check_vg_size

#  chown  nagios:nagios   check_vg_size

Now, you can check your volume group free space,

-w specified to Warning Status
-c specified to Critical Status
 
#  ./check_vg_size  -w 500 -c 300 -v vg0
VG vg0 OK  Free Space 2230 GB gross


The above command pointing to warning and critical free disk space status.

If the script is functional, open your nagios nrpe.cfg file and add the below line into it.
 
# vim /usr/local/nagios/etc/nrpe.cfg

command[check_vg_size]=/usr/local/nagios/libexec/check_vg_size  -w 500 -c 300 -v vg0

On Nagios Server :

Open client configuration file and define the service,
 
# vim /usr/local/nagios/etc/objects/host.hostname.cfg

define service{
        use                             generic-service
        host_name                       host.hostname.com
        service_description             LVM SPACE
        check_command                   check_nrpe!check_vg_size
        }

Save and execute below command to check the configuration whether is it right?
 
#  /usr/local/nagios/bin/nagios -v  /usr/local/nagios/etc/nagios.cfg

output should be :

Total Warnings: 0
Total Errors:   0

Things look okay - No serious problems were detected during the pre-flight check

Finally, Restart the nagios server :
#  /etc/init.d/nagios restart

Running configuration check...done.
Stopping nagios: done.
Starting nagios: done.