I have a laptop with two 500 GB internal SSDs that uses a dual boot setup, with Windows 10 installed on the first internal SSD and Ubuntu 18.04 installed on the second internal SSD, which has been working great so far.
I also have a 1 TB external SSD, and have been trying to install Ubuntu 16.04 on that. However, if I do install Ubuntu 16.04 on the external 1 TB SSD, it breaks the Ubuntu 18.04 installation on my 500 GB internal SSD (that is, I have to use the boot repair tool to fix GRUB). Furthermore, I’m also unable to actually boot into Ubuntu 16.04 on the 1 TB external SSD I just installed it on, which has left me scratching my head. This is the installation process I followed to try and install Ubuntu 16.04 on my 1 TB external SSD:
1) Using a bootable USB, I choose the Try Ubuntu without installing option.
2) Once Ubuntu has booted from the USB, I start the installer called Install Ubuntu 16.04.6 LTS
3) After getting to the 4th menu, I choose the Something else installation type option
4) I see that the 1 TB external SSD is under /dev/sdb, so I create a swap area as the first partition (/dev/sdb1) and an Ext4 journaling file system as the second partition (/dev/sdb2) with Mount point set to /
5) In the Device for boot loader installation dropdown box, I choose the 1 TB external SSD
6) With his done, I click on Install Now, which completes successfully
However, when I then restart my computer, I’m unable to choose the 1 TB external SSD as a bootable drive, and if I try and boot back into Ubuntu 18.04 that was installed on one of my internal 500 GB SSDs, I get a GRUB error which requires me to use boot repair to fix it (thankfully Windows 10 didn’t explode like the 2 Ubuntu versions did).
Right now I’m at a loss for what to do next, as I’ve spent the entire day trying to figure out what’s going on. Any help would be much appreciated.
