Let me warn you: You likely don’t want to do this but in case you do, for example because you can only boot a Debian live CD but want to install Ubuntu, be my guest (no guarantees, no warranty, no liability yada yada):
- boot into debian live CD image, install gparted, shrink and move ubuntu partition to the end
- follow debian guide to prepare the live cd environment:
- Before you got to 2, disk partitioning, jump to the ubuntu guide
- now first change the package sources:
- nano /etc/apt/sources.list
- replace sources with
deb http://archive.ubuntu.com/ubuntu focal main restricted universe multiversedeb http://archive.ubuntu.com/ubuntu focal-updates main restricted universe multiversedeb http://archive.ubuntu.com/ubuntu focal-backports main restricted universe multiversedeb http://security.ubuntu.com/ubuntu focal-security main restricted universe multiverse
-
- we have to add the public key, so run apt-update first
- in the current case, missing public key is 871920D1991BC93C
- run
gpg --keyserver keyserver.ubuntu.com --recv-key 871920D1991BC93C && gpg --export --armor 871920D1991BC93C | sudo apt-key add -
apt update
-
- then install from ubuntu guide:
apt install --yes debootstrap gdisk zfs-initramfs
- now follow ubuntu guide with partitioning
- Beware:
when creating rpool, include -o feature@log_spacemap=disabled – otherwise boot might fail
* in step 8, create /boot/efi manually