I guess it is probably a little early for this as do-release-upgrade does not find the new 26.04 LTS version - but do you have a timeframe to make Ubuntu 26.04 LTS an “A” rated OS for Virtualmin and then will i be able to upgrade without issues.
While setting a timeframe has not been a Virtualmin thing since the start, as it also sets unreasonable expectation that could easily break if testing and preparing takes longer or another priority takes center stage preventing the deadline to be met.
I can tell you this about the industry as a whole.
When new OS’ drop, I would recommend waiting 3-6 months at least before assuming it is going to be fully supported across the board, especially when an existing LTS (long term support) version is still available within the ecosystem.
The 3-6 month and sometimes even 12 month window is so that sufficient bug testing, major architecture changes (as major version 24 to 26) bring breaking changes and significant changes which need to be addressed, tested and implemented before they can be officially considered supported by the software.
Remember, 26.04 was only release last month. Remain patient and keep your eyes on the forums for updates.
A big issue here is beta testers. At most the staff can check all of the ‘main stuff’ to make sure it installs correctly. This isn’t a product that lends itself to beta testing as most users need it to work as close to flawless as possible from the start.
I was an Ubuntu fanboy but the arrival of snaps has moved me firmly to Debian - it is almost as though snaps are an attempt to make Ubuntu a better endpoint distro rather than a server.
snaps by Ubuntu is their attempt or flavor at similar systems like flatpak and appimages whereby they pack the app with it’s dependencies in a way that ensure no conflicts with other apps or system installed dependencies. IMO, it’s a work in progress, some issues still exist within their implementation but their intentions are pure. I personally like Debian for it’s slightly lighter, and more rock hard design.
Though Ubuntu is known for stability while also packing in a bit more “bleeding edge” newer packages by default. So it really comes down to what you’re familiar with, and what your objective is.
I believe Ubuntu offers paid support. Some companies require/feel safer with that option. Imagine just going to the freelance market whenever you have a problem. Decades ago when I used cPanel I found that if I ran into a problem I couldn’t solve, cPanel wasn’t gonna be much better though.
Both @stefan1959 and @ID10T have given two equally good answers on this point.
If you’re proficient with your Linux skills, it’s often as simple as “personal preference” - @stefan1959
If you’re less proficient or need more hands on assistance with things, while NOT part of the OS itself (as you can install and run it for FREE), “Ubuntu offers paid support” - @ID10T
The irony is, their both based on the same upstream source code. Debian. However Ubuntu has taken the Debian’s work, added some additional layers, and improvements that may or may not be relevant to your needs. Ubuntu also does more frequent “feature based” updates throughout their life cycle while Debian has built a rock solid OS at its core and focuses on keep every distro distraction free.
Both have their place in the overall ecosystem, so the choice is yours.