Debian of course.
Thatās exactly how I installed it. Yesterday.
I really donāt get what @1cloud is after.
Using these: https://cloud-images.ubuntu.com
While there is a minimal image available, itās not in the correct format for all clouds to initialise.
For example:
The virtual disks are about 500MB, how minimal does that sound?
Iāve been playing around with AlmaLinux recently, with the occasional quirk, but overall optimistic results. This is my current state of experimentation as of about an hour ago.
I never change nor major-version update OSās without extensive testing (probably more than is needed) unless itās an emergency sort of thing. Iām updating the results of this particular round of tests because I assume that some people may be interested, and the rest can look at the title and skip those threads.
You can read more about AlmaLinux here if youāre interested. Itās a project that Igor Seletskiy and his CloudLinux company are sponsoring. Itās in RC right now and is expected to be ready for production use in a few weeks.
Richard
Since the ISO download from Ubuntu is 1.1 GB, sounds pretty minimal.
Or not.
Or maybe.
Or who knows?
Iāll go and ask a few questions on a forum somewhere, perhaps someone might know. 
Would be helpful if I could find a thread related to OSās to use for Virtualmin too, any ideas on that?
Why you are being so completely, intentionally, and frustratingly obtuse is anybodyās guess. If I had to venture a guess myself, Iād say youāre just trying to sound smart when you really have no idea what youāre talking about.
There is only one Ubuntu Server 20.04 LTS installer. I donāt care where you get it, how big the file size/disk image/whatever you want to call it is.
There is only one.
Run it.
DO NOT add any additional software options during the installation which is on the screen shot I posted before.
Then you will be running the base, bare bones Ubuntu Server 20.04 LTS software.
I canāt explain it any more simply than that.
Good luck in your search for whatever it is youāre looking for that Iām sure doesnāt exist.
Iām guessing this isnāt the right place to start asking about cloud-init then?
Probably not.
You need to start with a minimal installation. How it got on the machine is irrelevant. But in the time youāve spent on this thread, you could have installed from ISO several times over.
Unless your host doesnāt allow that, of course, in which case I personally would find a new host. But to each their own, I guess.
Richard
Iāve already found a solution, will leave you boyz to it, hopefully you donāt get your ISOās stuck together.
For anyone thatās interested the default Canonical cloud images appear to be minimal server installs.
Made an ESXi > Debian. 