On Tue, Oct 1, 2019 at 1:32 PM Elliot <elliot.li.tech at gmail.com> wrote: > In my career, I've managed many Debian, Ubuntu, Fedora, and CentOS > systems, and I found that in-situ upgrading of Debian, Ubuntu, and > Fedora are usually easy and convenient. I'll concur in my experience. I've upgraded a number of Ubuntu servers through major version updates. The longest jump I have is on Fedora Server. One particularly central and critical server was built before I arrived, with Fedora 18. I have personally upgraded that on every release starting from 21 on up to the current 30. It's certainly possible to have major version upgrades be reliable. The big trick is to read release notes for any software you are using and note any issues they mention.