I have a UEFI netbook with an installed Lubuntu 20.04 where I can't install grub on the hard disk (strange problem with the UEFI/BIOS system). But I can launch it with supergrub2. It finds the hd partition and launches it. Now I would like to create a bootable usb stick (the netbook looks for a usb stick by default) which contains the EFI partition and grub which then starts the ubuntu on the hard disk. How can I do that? Thanks!

  • 2
    You need the ESP on flash drive and if you can boot Ubuntu, you just install the UEFI version of grub to flash drive with removable parameter. You will probably have to add your own grub boot stanza, but may be able to configfile boot into grub in your install. It could be just 'sudo grub-install --removable /dev/sdX. Where sdX is your flash drive. But before I had to create & mount ESP & /boot and use those in command. Post label of flash drive. lsblk -f Also: askubuntu.com/questions/344125/…
    – oldfred
    Aug 20, 2020 at 15:10

2 Answers 2


thanks for your ideas. I think starting from usb doesn't work as well because of UEFI/BIOS bugs. But I found a solution:

  1. get Ubuntu 20.04 mini.iso (see post 'Installing GRUB onto a USB stick (Server 20.04)'
  2. burn iso to a usb stick
  3. append the menu entry found in /boot/grub/grub.cfg on my hdd to the one on the usb stick (I had to change hdb2 to hda2 and hd1 to hd0 for some reason).
  • +1; Thanks for sharing your solution :-) It would be nice if you also provide a link to download the current 20.04 mini.iso,
    – sudodus
    Aug 22, 2020 at 13:20

You can try the following method:

  • Put an installed Ubuntu system into a USB drive (size >= 16 GB) by extracting/cloning from a compressed image file. Use the method described in the following link,

    If you need not encrypt the drive, there is an easy alternative

  • Boot into the Ubuntu system in a USB drive.

  • Run the following command line (in a terminal window)

    sudo update-grub
  • Reboot

If there is a good Ubuntu system in the internal drive, it should be recognized by update-grub, and a grub menuentry should be created, so that you can boot into the Ubuntu system in the internal drive.

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