Problem unmounting NAS

Hey everyone,

thank you all for the great work. Volumio is a great solution to my initial problem: listening to my mp3 collection (on an external hdd) without a pc. It is great that volumio supports my DAC (V90-HPA). The sound is just as good as it gets!

Now to my problem:
I was not able to mount network storage to volumio. (The network storage was either an external drive mounted to my router TP-Link WDR 3500). So I mounted the drive directly to my raspberry. Now the problem is, I cannot remove the drive I mounted. whenever I try to remove it, the interface seizes to work and I have to log in through SSH and reboot. Can you advise on the command code to unmount the NAS share, so that it disappears from the volumio interface?

Thank you and regards,