WARNNG: DO NOT BLINDLY COPY ALL! Do it line by line.
First use install_UBUNTU_zfs.sh, then configure_UBUNTU_zfs.sh.
This installation works on BIOS system. Installed from Debian live CD, because VPS do not allow to add custom ISO and limited to 3 images. Eaasy to adopt to the EFI system. Consult OpenZFS How-to
Last steps like user creation, etc., please look OpenZFS docs (link is in Source list)
Sources
OpenZFS docs
cryptsetup error patch from launcpad bugs
Remote unlocking native encrypted ZFS
Later....