{The thread will be what it is, but I envision a place to share stories, frustrations, and maybe even get a bit of tech support.}
I recently tried to upgrade the OS on a website I manage, and it was an utter nightmare.
Actually what I did was more sensible - spin up a new VM which would have the OS and programs like apache and php and such already on it, and then make tweaks and move my site there. I was encouraged to add virtualmin, which would make it easy to manage.
Noooooooooooooooooooooooooooooooo!
These things are a curse. I spent days trying to move away from the default document root of /home/some_username/public_html and put it under /srv/website_name where it belongs. Not chirpin' possible. Virtualmin has its fingers everywhere. In the end, php was running under the some_username username and I couldn't get it to start under something else (like the one apache2 uses, or my own username), and therefore php files could not be run unless I chowned them all, or chmod o+r for them all, neither of which makes life easy for me or safe for the site.
If anybody knows how to beat virtualmin into submission, I'm all ears. Otherwise I'm ripping the thing out and starting from scratch, with the console. Sure, site management tools can be useful, but if you need them, you're better off without them, and if you don't need them, you're better off without them.
Jose