Ubuntu – Make Full Install to USB Able to Install Ubuntu


Have Live USBs for installing Ubuntu.

Have Full install USBs for regular use.

Would like to be able to use the Full install USBs as installers to eliminate the need for the Live USBs.

Installed Ubiquity to Full install USB per: How to install ubiquity to Full install bootable USB

The installer seems to run fine up to the point of adding names and password, then it crashes.

Maybe Ubiquity can not find a package to install?

How can I make a Full install USB that can be used to install Ubuntu?

Can it be made to install various flavors of Buntu also?

Best Answer

Install Ubuntu using Full install USB*

Nowadays USB drives are becoming large enough that having an extra ISO file is no big deal.

Place your Ubuntu ISO at the root of the USB.

Modify the USB's grub.cfg by adding this menuentry to /etc/grub.d/40_custom and running sudo update-grub:

menuentry "Ubuntu-18.04 64-bit ISO" {
    set root=(hd0,1)
    set isofile="/ubuntu-18.04-desktop-amd64.iso"
        loopback loop $isofile
        linux (loop)/casper/vmlinuz boot=casper iso-scan/filename=$isofile splash --
        initrd (loop)/casper/initrd.lz

(hd0,1) assumes root is sda1.

You will then have the option to boot the USB drive to a Live installer system.

*Ubuntu 19.10 and later use grub 2.04 which does not boot ISO files. To create a Full install that uses grub 2.02 see How to Create a Full Install of Ubuntu 20.04 to USB Device Step by Step NOTE 1 Re: mkusb usb-pack-efi option.