Library additional hard drive in ubuntu 14.04

Hi, I'm new using Plex, install it on a PC with Ubuntu 14.04, then add an additional disk 500gb gave Ext4 format, this album I want to save all my files and then add the libraries, but when selecting the folder Current transition not me any from disk to install again, but if I believe in / home / videos if you show me the folders, I have to make an extra configuration to hard disk? plex or server so I can recognize what a route ...

 

thank you very much