The mini.iso is output of the debian-installer build and continues to be available at http://archive.ubuntu.com/ubuntu/dists/focal/main/installer-amd64/current/legacy-images/netboot/mini.iso. It has not been dropped, but neither is it an image that we recommend users use for installation. The mini.iso has in fact never been a “supported” install method for Ubuntu, and is not part of the test matrix for Ubuntu releases. And there will not be an equivalent mini.iso image for use with subiquity.
1 Like