On Tue, May 26, 2020 at 3:54 PM Troy Dawson <[log in to unmask]> wrote:
>
> Although in the past the official policy of Red Hat was that you needed to do a fresh install going from EL N to N+1, that is starting to change.
> There is an internal team called "LEAP" whose job it is to make sure you can do that.
> I believe RHEL 7.8 to RHEL 8.1 was the first that you could officially do that.
> I don't know all the details.  all I know is "we're working on it."
> I'm pretty sure that at the current time we aren't as smooth as Debian, they've been doing it much longer.
> But we're getting better, and for RHEL9, LEAP is being involved from the start.
> So maybe in a few releases / years people will be able to say our updates are as good, or even easier than debians.

Been there, done that. It works great until it doesn't. While updating
the RPM's may be feasible, there have been subtle changes in
filesystems which man starting with an old filesystem is prone to
errors, and upgrading in place is.... not a reliable process. *All*
operating systems are prone to such issues, unless you can basically
mount the old file system as an image and apply the updates from
outside. I've done upgrades with approximately 20,000 Red Hat based
systems, over my career, and others. If you were foolish enough to use
ReiserFS, for example, you'll *really* need to rebuld your filesystems
in between OS upgrades..