Removing Install Screen when booting from Live USB with persistence on 20.04 Ubuntu Server

mkusb can clone most Linux iso files but can make persistent live drives only for Ubuntu Desktop, the community flavours (Kubuntu, Lubuntu ... Xubuntu), Debian live and some respins (distros based on Ubuntu and Debian, where the boot structure is not changed too much).

mkusb cannot make persistent live drives from Ubuntu Server iso files. But you can use the following command line for Ubuntu Live Server 20.04.3 LTS,

sed -e 's# append   initrd=/casper/initrd quiet  ---#append initrd=/casper/initrd persistent --#' -e 's#\tlinux\t/casper/vmlinuz   quiet  ---#linux\t/casper/vmlinuz persistent --#' ubuntu-20.04.3-live-server-amd64.iso > persistent-ubuntu-20.04.3-live-server-amd64.iso

Copy and paste it into a terminal window. It is very important that you get it exactly correct. Otherwise it will fail. Explanation: Editing the iso file can be done within very strict limits. The total size must be preserved and only text strings should be modified. So I replace quietand some whitespace and one hyphen with persistent both for booting via syslinux in BIOS mode and via grub in UEFI mode.

Now you can clone the modified iso file with a cloning tool, for example mkusb-dus or mkusb-plug, for example

dus persistent-ubuntu-20.04.3-live-server-amd64.iso

The result will be a persistent live drive, that works both in BIOS mode and UEFI mode.

I have no method to make it start with a command line. You still have to switch to a virtual text screen with ctrl+alt+F3 (or ctrl+alt+F4 ... and back to the menu with ctrl+alt+F1).