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I'm new here and new to the world of Linux.

I followed instructions on how to create a bootable linux drive on my external SSD (240gb SSD with 1x 20gb partition and 1x 220gb partition).

I installed Linux on the 20gb partition to these instructions: How to install Ubuntu on portable external Hard Drive? (except I didn't "try linux" from the bootable USB device, I installed it), and I put the bootloader on the ext4 that I created on the 20gb partition.

It's all installed now and works, however when I boot up, my machine now goes to Ubuntu to ask if I want to boot up Windows 10 or if I want to boot Ubuntu. This is annoying and I want to change it back to normal (auto boot to windows 10 unless I say otherwise).

Next thing that is very problematic is that if I unplug the external SSD, my original Windows 10 can't boot at all, with an error message saying "Reboot and Select proper Boot device", which means now to boot Windows 10 from my primary drive, I NEED the external SSD plugged in.

I would like Windows to boot as normal (from my primary drive, automatically), unless I specifically press F12 and select to boot from Ubuntu. Can anyone help?

snodge182
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1 Answers1

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Ubuntu's Ubiquity does not correctly install to external devices. See this bug, but you do not need to reinstall:

https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/1396379

Both Windows & Ubuntu are installed in UEFI boot mode. Not sure why you do not have an UEFI boot entry for Windows. This should add a Windows UEFI boot entry or you need to run Windows repairs from your Windows repair/recovery flash drive (you did make one?)

sudo efibootmgr -c -L "Windows Boot Manager" -l "\EFI\Microsoft\Boot\bootmgfw.efi"  /dev/sda -p 2

That will allow you to boot Windows or Ubuntu if external plugged in from f12 UEFI boot menu.

But if you ever want to boot external on another PC, you need to have grub boot loader on the SSD. UEFI only directly boots external drives from /EFI/Boot/bootx64.efi as a USB drive boot entry (same type as installer was).

Since you use Windows to make SSD as gpt, you have the Microsoft Reserved partition as first partition. That is required by Windows before first NTFS bootable partition on a drive. But since you cannot boot Windows from external, it is not required. And then can be converted to an ESP - efi system partition with gparted as FAT32 with boot/esp flag. Then you can use Boot-Repair and its advanced options to install grub to external drive. Afterwards double check that /etc/fstab is updated with new UUID from ESP on external, not existing sda2's UUID. Otherwise major grub update may update internal but not external drive's ESP.

After creating ESP on sdb, use advanced options to choose install on sdb2, and install grub to sdb drive.

https://sourceforge.net/p/boot-repair/home/Home/

oldfred
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