I have a Intel NUC with Ubuntu 16.04. There are two external USB disks, one with external power, one powered by USB port. Both are mounted via UUID in fstab. Now I bought a new disk the same model of the USB powered I already have, the disk is this: https://www.amazon.it/gp/aw/d/B00KWHJY7Q/ref=ya_aw_od_pi?ie=UTF8&psc=1 I plugged it and it's automatically mounted on /media/usb0. I unmounted it, launched parted and deleted the existing partition. Then I created a new primary partition on the full space and created a ext2 file system on it. Discovered the UUID with blkid and added the line in fstab. The mount point exist and it is owned by the user just like the two mount points for the existing disks. If I reboot the computer it won't start, it stops with a blinking cursor, bigger than the normal cursor of the shell, like X is trying to run, but somehow couldn't. I tried to unplug the disk and Ubuntu starts. Then if I plug the disk and run mount -a as root the disk mounts correctly. It just won't let Ubuntu to boot. Any idea of what I am doing wrong?
The mount-point in your fstab-line must be an existing folder.
When you plug-in the device to the running system, this folder will be created, in your case it is the folder
/media/usb0. This folder will disappear after unplugging the device. If you mount with
fstab using this folder, you have to create that folder first.
sudo mkdir /media/usb0
will create the folder. You could use any location and any name for the folder which you use as mount-point, this is up to you, the mount-point in your fstab-line must point to this folder and the folder must exist, otherwise the mount-attempt will fail.
Are you plugging this drive into a USB 3.0 port?
There's a good chance that your USB port is not supplying enough power for the drive. Try using a different USB port for the 'failing' drive and see if that works. If not, then get a
POWERED USB hub (1), plug the hub into the computer, and the drive into the hub. See if that solves your problem.
POWERED USB hub has an AC adapter to supply power to the USB ports.
Let us know. Cheers, Al