On Tue, 2017-03-21 at 16:28 +0100, Michael Matz wrote:
That question implies to never dare testing a different approach
than what is currently in use - as you will not be able to guarantee that a new idea as such works better than the old way of doing things without testing it.
Well, but it must at least be sound if it causes work for others, right? So, proving might be a bit too harsh indeed, but the transactional updates (at least as I understand them right now) seem a bit dubious in that they replace a certain set of problem with other (IMHO worse) problems.
Don't get me wrong: I like the fact that people DISCUSS about the solution and potential issues they see. And I'm sure Thorsten agrees on that too. Just don't always phrase everything in a way stating that all the new stuff just is more broken than all the old broken stuff.
How many of the problems solved by transactional updates are actually solved by the required reboot (or could be solved by that alone), and not by the installing-into-snapshot aspect?
Updating a system is a tricky thing. We have been using zypper dup from within a running session for a long time now, with the chance to rollback when it fails. Every so often users complain the session crashed halfway leaving them in a bad place. GNOME upstream tries to eliminate this by downloading all the updates to the local cache, reboot the machine to a minimal running system, update all the packages and reboot the system into a working system (unlike Windows, though, it does NOT tell you when you have to do it: you actively click on 'reboot and update' from within GNOME Software or select the checkbox 'perform updates on next boot' when you reboot/shutdown your system) - of course everybody complains that booting to apply updates is not what we are used to do on Unix/Linux, and if you understand the setup well enough, you can actually judge on it - most 'users' I tend to talk to would not know how to get started. Transactional Updates does a similar thing, from the other angle: update a snapshot that you will boot to once the update is complete. Of course, just like GNOME's approach, it also requires you to reboot the system. And in plus it requires a very strict separation of program files managed by the package manager from the data part (as would be the case with rollback). I'm not yet sure if any of the methods being implemented / tested at this moment will give us ALL solutions to all problems... but exploring the options is certainly the way to go. No shame in admitting at one point 'oh well, that did not work out as expected - but we learned this and that about the problem' Cheers, Dominique