First create the ibay music and enable web access from local network or from the internet.
It’s all standard features of server-manager and manual explains it.
The second step is to add the second hard drive and mount it to the folder /home/e-smith/files/ibays/music/html
Where is how-to add second drive that explains the same scenario in details.
It will be much easier and more consistent to do it this way then mount drive to nonstandard /mnt/driveb/music folder and adjust configuration of server to accomodate it.