A mini-ISO is a minimal image that needs an active internet connection to download all the required packages to install a distro.
Ubuntu used to have an unofficial one in the past, but it was discontinued a few years back.
But now, it might be making an official comeback.
Mini ISO With Ubuntu 23.04 Lunar Lobster Release
In a recent Ubuntu developer mailing list discussion, plans were shared by a few devs about the imminent launch of mini-ISOs for Ubuntu.
What is happening?: It all began when Ubuntu member, Aaron Rainbolt, proposed a project that would provide similar functionality as the mini-ISO of the past.
He was ready to either use a customized version of the existing Debian installer, or create a new one, with the potential to make it into an official Ubuntu flavor.
That is when, Lukasz Zemczak, developer at Canonical, shared what they were planning for Ubuntu.
He mentioned that Dan Bungert, the maintainer of Ubuntu's Subiquity installer, was working on a project called 'ubuntu-mini-iso.'
They already have a prototype ready and are trying to build it using the official infrastructure.
Furthermore, he shares some details on how the mini ISO works.
It is a small bootable ISO that can be used with small storage devices like CD/USB drives, or even via UEFI HTTP.
For the latter, a dynamic TUI (terminal user interface) menu of the Ubuntu images will be shown, allowing you to download and install the image of your choice on the target system.
The Ubuntu mini-ISO uses simplestreams to select the images, allowing for various customizable image selections.
As for the installation, it downloads the selected ISO into the memory and chain-boots into it, allowing the installation of any image the usual way.
It does have some limitations because it requires sufficient RAM.
Furthermore, Dan expects the size of the mini-ISO to be somewhere in the ballpark of 140 MiB.
He also mentions that there is potential for the ISO selection menu to support the various flavors of Ubuntu.
When to expect?: If everything goes as planned, then the mini-ISO will be introduced with Ubuntu 23.04 'Lunar Lobster.'
Steve Langasek, the Ubuntu developer says:
Unlike the previous mini.iso, we fully intend that this be asupported and tested image!
And crucially, unlike the mini.iso which bypassed all of the installer logic in favor of raw package selection and therefore gave a different - unsupported - install result vs the installer on our full flavor images
This new mini iso will boot the actual flavor installer and so any divergences in the installed system would simply be a bug.
If curious, go through the mailing list thread to dive deep into this.
💬 What do you think about a new Ubuntu mini ISO? Would you want it for your use-case? Share your thoughts!