I am trying to install Elementary OS Loki onto a Seagate Backup Plus Slim 2TB portable USB HD, I don't think my problem is specific to the OS. The install completes successfully (using the option to erase the entire drive and letting Elementary do what it prefers), however:
- I am unable to see the drive when set to UEFI, only Legacy
- When I select the drive from the boot menu I greeted with "No bootable device -- insert boot disk and press any key"
What I have tried:
- Trying the install again but following this guide: http://linuxbsdos.com/2013/10/23/how-to-install-ubuntu-13-10-on-an-external-hard-drive/, since the installers for Ubuntu and Elementary are nearly identical. To summarize, it calls for using the partition manager from the installer to create a partition for root (10GB for me), a paritions for swap (2GB for me), and a partition for /home (502GB). I tried this multiple times, no difference other than one attempt where I couldn't start the install because creating the root partition somehow left 33MB of freespace before it despite my best efforts and multiple attempts at that.
- Running GParted from my Elementary OS live USB and setting up GPT instead of MSDOS as my partition table. Creating a 10GB partition for root, a 2GB partition for swap, and a 502GB partition for /home. Ran the install again (this time manually selecting my partitions that I created with GParted). No difference.
- (Update 1) I tried to follow another guide: https://help.ubuntu.com/community/UEFI. So, I created a new Elementary OS installation USB ensuring that it was UEFI only. I use GParted from that to then create an ESP EFI System Partition using FAT32 and set the boot flag. I also created a swap partition, ext4 partition for root, and an ext4 partition for /home. Installation seemed to go smoothly, but again there was no difference in my outcome.
- (Update 2) Using the partitions from my previous attempt (3), I ran the install again ensuring that the EFI partition (/dev/sdb1 in my case) was selected for the boot install (even though the guide from attempt 1 says that you should select the drive for boot install, not the partition).
This is mostly all new territory for me, so I am sure there is some obvious issue that I am just not knowledgeable enough to find in my search.
- (Update 1) Added my latest attempt to the What I've tried: section. I think my future attempts will use Ubuntu itself rather than Elementary OS, just to be more confident in the guides I find (there are next to none for Elementary itself).
- (Update 2) Added my latest attempt (and it worked!), going to put the full solution as an answer and accept it.