Ok I've added a new HDD. The strange thing is that for this disk "Volume_2 Used", it does show the number of MB's used. I guess I'll see what will happen now that I've enabled it (still 0MB for volume_1 right now).
[EDIT]Unfortunately I don't see an option to send a notification if the quotas are exceeded, so that makes this feature not very useful for me.[/EDIT]
Also the recycle bin is not enabled while it hanged, still I had to unplug the NAS since It wouldn't shutdown.