Is an internal HDD with Ubuntu automatically bootable from an external USB case?

Solution 1:

Because of the internal USB to SATA bridge adapter used inside of external disk drive cases, transplanted disk drives may require reformatting before they can be used... so the answer is "maybe".

Some of the older/cheaper cases have limitations on how large a drive it will support. Usually if you're under 1TB you should be fine.

"Standard" Windows won't boot from an external USB drive. On the Ubuntu side, if you've edited /etc/fstab, and used device names (ie:/dev/sda2) in your mount statements, instead of UUID's, then there may be a booting problem as device names can change depending on your current hardware configuration, UUID's don't change.

If you cloned from HDD to SDD, you'll probably have to disconnect the HDD or you'll have booting problems because the UUID's are duplicated on both drives. You can change the UUID's on one of the drives using sudo blkid and (sudo tune2fs or gparted) such that there are no duplicated UUID's.

On a hardware note, I've had really bad luck with Orico external cases. I just sent back two to Newegg because they didn't work. Another case, using the same disk drive, worked fine.

Solution 2:

Yes - Linux works from USB - and I am learning now, that Windows can work too

I have done it many times, with HDDs and SSDs. It should definitely work in the same computer, and will work in many other computers too, particularly if you have not installed any proprietary drivers. (It works in my Toshiba Satellite Pro bought 2013, but another model than yours.)

If it does not work, I would suspect

1. either the casing (some electronic component or some programming in the casing) or the combination of the computer's USB system and the casing,

2. or the UEFI/BIOS system in the computer. If the drive is installed in UEFI mode, there might be problems, particularly if the UEFI system does not follow the standard specifications.

3. [Edit] There are general tips and detailed instructions in the following link and links from it to help you make a portable installed Ubuntu system in an external drive,

   Boot Ubuntu from external drive.

Solution 3:

Installing a system in a specific machine on a specific drive does not guarantee it will be bootable on other machines:

1. The launcher may be on another drive
2. If your launcher is an .efi file, it won't work on legacy systems booting exclusively from MBR launchers.
3. If using secure boot, you may not always have correct signature to boot.
4. Boot partition is not guaranteed to be on the same drive when applicable

Excluding all above:

1. Motherboard can prevent booting from USB due to configuration or legacy nature
2. Booting may fail due to missing driver for a particular system
3. USB bridge may be too slow to initialize and prevent detection on time by motherboard as bootable.

To make it short, no, it won't be automatically bootable, you must ensure your storage and target system has everything required.