0

all my ubuntu derivates are installed on external disks. I installed them without regards of the implication. Now, I want to be able to plug them onto other computers and want them still be bootable. That turned out to be a huge problem. Apparently, during installation, ubuntu installs the necessary files for booting inside the efi partition of my system. Trying to boot by selecting the disk directly from BIOS doesn't work.

What are the steps necessary to make them bootable on any PC, considering secure boot could be enabled? I would be happy if I could select the disk just directly from the BIOS boot prompt.

user2762996
  • 153
  • 1
    You've provided no OS & release details. Please provide some specifics. – guiverc Aug 05 '21 at 13:25
  • 2
    You will need ESP - efi system partition (FAT32 with boot,esp flags) on external drive. I always include that on every drive, just in case. If very large drive, ESP must be nearer beginning of drive. UEFI suggests first, but Windows makes it second or even third partition, but smaller partiitons before it. Then you need to edit fstab with new UUID for ESP & reinstall grub. https://askubuntu.com/questions/16988/how-do-i-install-ubuntu-to-a-usb-key-without-using-startup-disk-creator/1056079#1056079 & https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1396379 Old bug but still valid. – oldfred Aug 05 '21 at 14:10

0 Answers0