I never put F28 onto my wife's machine, because I had too
much trouble with it on mine. I didn't mean to now, except
temporarily. I ran dnf upgrade, then did the dnf system upgrade, giving
the version to upgrade to as 28.
Then I did the special system-upgrade reboot -- and it hung. I
tried rebooting several times, but succeeded only in getting it to hang
on a different error message, one that it now gets every time.
That message is long, complex, and ambiguous in several places,
at least to the uninitiated. It begins by saying something like "You are
now in emergency mode." Then it talks about logging in a/o giving
commands, some as root. Finally it says you can try to continue by
hitting ^D; I've done that, and it tries to reboot but hangs with what
seems the same message.
I tried using UCBD, which did boot; but it was way over my head.
So I tried a few options like boot and install; no joy. All the things I
thought might help (essentially the ones not meant for exploring
hardware) did me no good. I did try its supergrub2disk, which I've used
before on its own, but got nowhere with that, either.
That PC is now running a live medium of F29. I could tell it to
install to hard drive; or I could burn a medium for netinstall. (She does
say she has not done significant work on her important data since the
backups I made before upgrading her to F27.)
Beartooth Staffwright, Not Quite Clueless Power User
Remember I know little (precious little!) of where up is.