Linux, External SSD & Sierra

[mw360]

I've been dabbling with Linux to try to find a distro I can use. Doing the following on my Yosemite iMac..

1. Flash the ISO to a USB stick using Etcher
2. Hold down the Option key to boot from the USB stick
3. Use the installer in the Live ISO to install Linux to an external SSD
4. Hold down the Option key to boot from the external SSD

This worked for CentOS, Elemetary, Mint, and a couple of others. I've recently upgraded to Sierra, and I've tried again with Ubuntu and Ubuntu Studio, but the above steps no longer seem to work.

In Ubuntu Studio, the installer fails to install Grub and that's the end of it. In Ubuntu the installer works, but the SSD is not available in the boot drive selector. Has something changed? Do I need to do some extra steps? (I'm not installing Linux to my system drive, nor do I want to make any changes to it.)

 

[lowendlinux]

it won't be available without refind because the Mac cant read and ext4 formatted drive. You can install grub manually but its a bit of a PITA and which version of Ubuntu are you using Apple Thunderbolt support wasn't added until 3.17 and even if it's there Canonical might not have set it to load..

 

[supermariofan25]

I've been dabbling with Linux to try to find a distro I can use. Doing the following on my Yosemite iMac..

1. Flash the ISO to a USB stick using Etcher
2. Hold down the Option key to boot from the USB stick
3. Use the installer in the Live ISO to install Linux to an external SSD
4. Hold down the Option key to boot from the external SSD

This worked for CentOS, Elemetary, Mint, and a couple of others. I've recently upgraded to Sierra, and I've tried again with Ubuntu and Ubuntu Studio, but the above steps no longer seem to work.

In Ubuntu Studio, the installer fails to install Grub and that's the end of it. In Ubuntu the installer works, but the SSD is not available in the boot drive selector. Has something changed? Do I need to do some extra steps? (I'm not installing Linux to my system drive, nor do I want to make any changes to it.)

From my knowledge, Ubuntu puts grub on the internal drive despite being told to install to the external drive (At least when preforming an install under EFI mode). In either Ubuntu or Sierra, mount the respected EFI partition for both the internal and external drive. Once they are both mounted, the internal drive should have a folder called 'ubuntu' in the '/EFI/' folder on the root of the EFI partition. Move the 'ubuntu' folder to the '/EFI/' folder on the root of the EFI partition for the external drive (Create a folder called 'EFI' on the root of the partition if one does not exist). Now to make the drive visible in the boot drive selector, create a folder called 'boot' in the 'EFI' folder of the external drive's EFI partition. Move the file 'ubuntux64.efi' from the 'ubuntu' folder to the newly created 'boot' folder and rename it 'bootx64.efi'. If the file 'ubuntux64.efi' does not exist than it may be named 'grubx64.efi'.