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I would like to know how to create a portable installed Ubuntu system that is bootable in UEFI, as opposed to a persistent live system. I think I am encountering problems with non-volitile RAM.

I basically followed the procedure outlined in Portable installed system that boots in UEFI as well as BIOS mode, with several modifications. My laptop only boots in UEFI and does not have a BIOS (legacy, or UEFI disabled) mode, so I skipped the BIOS portion. The steps I used are as follows:

  1. On the target USB drive, create a gpt partition table, an EFI partition, root partition, and swap partition.
  2. Remove the internal hard drive on the laptop to make sure it is not altered or its EFI partition is not used.
  3. Power on the laptop with a LiveUSB stick and install Ubuntu 14.04 desktop 64-bit using 'Something else'.
  4. Power on the laptop with the target USB drive. The system boots successfully.
  5. Power on the laptop without any attached media. This causes a no bootable media error.
  6. Power on the laptop with the target USB drive. The system no longer boots.
  7. Power on the laptop with a LiveUSB stick, install boot-repair, attach the target USB drive, and run boot-repair.
  8. Power on the laptop with the target USB drive. The system boots successfully.
  9. Power on the laptop without any attached media. This causes a no bootable media error.
  10. Power on the laptop with the target USB drive. The system no longer boots.

My understanding is that UEFI stores the boot loaders in the EFI partition but keeps references to them in non-volatile RAM. When I powered up the laptop without the target USB drive in steps 5 and 9, the references were deleted and the target drive became un-bootable in steps 6 and 10. boot-repair is a symptomatic fix but not a permanent solution. Although I am able to install Ubuntu on a USB drive, it is not portable and relies on NVRAM.

My questions are:

a) What am I doing wrong?
b) Why are LiveUSB sticks portable, but not my target USB drive?
c) When I reattached my internal hard drive, the laptop is able to find Windows. How is this different from my USB drive?
d) Is there a fix for this?

share|improve this question
    
Plug everything in and run the BootInfo report and post link. Then we can see differences. It may be secure boot setting? Your UEFI should show USB drive and give you option to boot even if not in saved efi settings. But if secure boot is on and install is not secure boot it will not be shown. –  oldfred May 5 at 18:40

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