Moved to debian after using Ubuntu for a decade and I am not looking back. But I think Ubuntu was necessary for me to see beauty of Debian.
Would it be possible to switch from Ubuntu to Debian without having to reinstall the whole system?
I hope something like updating sources to debian unstable and doing apt-get upgrade should just work, but am afraid to try it on the running system.
Looking at the way Canonical is operating, as a Linux Mint Cinnamon user, I sure am glad they're building for a "if Ubuntu was ever to disappear" world.
"Its goal is to ensure Linux Mint can continue to deliver the same user experience if Ubuntu was ever to disappear. It allows us to assess how much we depend on Ubuntu and how much work would be involved in such an event. LMDE is also one of our development targets, as such it guarantees the software we develop is compatible outside of Ubuntu."
I think in theory at least if your username is anthropodie, you should be able to copy /home/anthropodie to an external hard disk just for backup, install your new distro, set up your new user and copy your user home directory back. Anyone tried this?
It would be slightly more work involving parted (or whatever partition manager you prefer) to create a new partition, resize existing partitions, etc., but quite doable (if tedious and time consuming).
Instead I backup my home dir with borg backup to drives/cloud.
I have a script to borg mount my most recent borg backup, so when I set up a new OS install, I just run the script and copy my files over from my backup to my computer's SSD.
I love this method because I can easily install a different SSD, switch to a new computer, or just do a clean OS installation very easily.
/home is kept intact. After installation of apps on new setup I don't even have to configure them most of times because they can find their config directories in /home/myuser/
It worked quite well for me, although there were a few issues (for instance, I didn't get kernel updates anymore, and when I fixed that, the Wifi driver was missing). There are probably still a few issues that went undetected and might cause problems later.
It's certainly possible, but I wouldn't recommend it unless you're willing to spend quite some time on it. And don't count on it working at all. (And backup your data. I didn't, and got lucky, but in retrospect, that was irresponsible.)
A good idea? No. If you need to ask, you will have regrets.
A fresh install would be faster, easier, safer, and more secure.