I have a request for Ubuntu: I need the team to update the Ubuntu iso on the download page with an updated installer, so that Ubuntu can successfully be installed on my USB drive.

I don’t like dualboot systems on my PC’s hard drive, so I decided I'd install the system on a flash drive; a safer way to install and use systems.

I did so, but the bootloader (GRUB) is installed on my PC instead of my destined USB drive, with the rest of the Ubuntu system, no matter what, so I can’t use Ubuntu on any other PC, like other systems like Chromium OS systems.

I can bootload Pop! OS an any PC because it does not depend on a bootloader/GRUB to access the system. But I don’t like Pop!_OS like I do Ubuntu.

Ubuntu team, please fix this in your isos so that GRUB won’t be installed on the PC and I can use my USB drive to use Ubuntu on any PC.

marked as duplicate by Panther, user535733, sudodus, karel, WinEunuuchs2Unix Jul 9 '18 at 1:58

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.


Just install to the USB in legacy mode. Trying a UEFI install to a USB risks leaving your system unbootable (without the USB) -- see bugs 1173457, #1396379, 1229488,... and add yourself to the "Does this affect me?" list.

The default install will create two partitions, a root and a swap. If you want something else (FAT for data exchange with Windows, no swap, separate /home, etc. select the "something else" for the install choice.

Doing a full install without any proprietary drivers should work in a good number of other machines, but will probably not be as portable as the install-media. Maybe an install-media created with mkusb with persistence would be the maximal portability solution, but you will forgo the regular security updates you would get with a full install.

  • If you do a BIOS/legacy install, you must, on partitioning screen, choose to install the grub2 boot loader into the Ubuntu drive. I prefer to use gpt and have both an ESP - efi system partition for UEFI boot and a bios_grub partition for BIOS boot. I have created UEFI boot flash drives, but process is a bit complicated. You have to manually copy /EFI/ubuntu from ESP on sda to ESP on flash drive twice. Second time into /EFI/Boot and rename shimx64.efi to bootx64.efi. UEFI only boots /EFI/Boot/bootx64.askubuntu.com/questions/786986/boot-ubuntu-from-external-drive – oldfred Jul 8 '18 at 21:15
  • @Scholeggo, If you can unplug the internal drive(a), you can install to USB also in UEFI mode as described in my comment at your question. Another alternative is described here: Installation/UEFI-and-BIOS – sudodus Jul 8 '18 at 21:24
  • Ubfan1, I did what you said and it worked (I don't know about sudodus' solution, but I did it anyway, but I'm sure your way worked)! You know, it's funny; I searched for a whole week trying to install Ubuntu and GRUB to my drive, getting complicated code and back and forth instructions that was guaranteed to put GRUB in its place, but got me nothing but stuck every time. This one small mistake: booting the installer from UEFI, no article or video stated that at all! Thanks really ubfan1. I really owe you one! – Scholeggo Jul 9 '18 at 5:27
  • @Scholeggo, Thanks for sharing your solution :-) and +1 for ubfan1. – sudodus Jul 9 '18 at 7:12

Full Install to USB - BIOS/UEFI

If you would like your USB drive to be able to boot from multiple computers, both BIOS and UEFI:

Use mkusb to make a Live system on the Installer USB (2GB or larger).

Use mkusb to make a Persistent system on the Target USB, 16GB or larger, using default settings with ~12GB persistence, (remaining NTFS partition is used as Windows accessible data partition).

enter image description here

Open GParted and delete sdx4, the ISO9660 partition and expand sdx5 into the recovered space, sdx being the device name of the Target drive.

enter image description here

Unplug or remove HDD before proceeding further, (optional but recommended, highly recommended in UEFI mode).

Boot Installer drive, select Try.

Insert Target drive

Start Install Ubuntu...

Select Something else.

Select sdx5, (on the target drive), and click Change.

enter image description here

Select Use as: ext4, Format and Mount point: /.

Don't touch any other partitions (unless adding a /home partition).

Select sdx5 as Device for boot loader installation.

Complete installation.

Cut grub.cfg from sdx5/boot/grub and paste to sdx3/boot/grub, overwriting the existing grub.cfg file.

Boot the target drive and run sudo update-grub to add all drives to boot menu.

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