Implementing admin configuration at server's end.

The configuration file is "gluster_vol_usage" created and maintained by
server itself.

Config file has first line containing server's ip under use from the available ones
and backup point ( path where all the volumes are located and over each volume
is used by one or many clients for backup ).

From second line onwards each line contains the configuration data which maps
each volume to its respective client_ip:FILESYSTEM.