Hi @ppaes
In the past, to solve this problem, I have installed a drive (as you did) and I proceeded as follows
I mounted the disk in the directory /mnt/newdisk (not in /var/lib/nethserver/ibay):
I copied folder ibay to the new disk
cp -Rf /var/lib/nethserver/ibay /mnt/newdisk/
I renamed the original ibay
mv /var/lib/nethserver/ibay /var/lib/nethserver/ibay.ori
I created a symbolic link
ln -s /mnt/newdisk/ibay /var/lib/nethserver/ibay
The directory /mnt/newdisk/ibay must be added manually to the backup
Once everything is working I deleted the old Ibay
rm -Rf /var/lib/nethserver/ibay.ori