Proposed F19 Feature: Fedora Upgrade - using yum

[Kay Sievers]

On Wed, Jan 23, 2013 at 7:50 PM, Lennart Poettering
<mzerqung at 0pointer.de> wrote:
> On Wed, 23.01.13 18:04, Jaroslav Reznik (jreznik at redhat.com) wrote:
>
>> FedUp is in fact yum-upgrade as well, but in dracut environment (aka off-line
>> upgrade). Some devels say that offline upgrade is only way. But on-line upgrade
>> is possible. E.g in Debian world it is even prefered method. In Fedora exist
>> upgrade using yum as unofficial method for long time.
>>
>> A lot of people are using upgrade using yum for long time and the "problem
>> ratio" was at least on pair with Anaconda upgrade. In fact most problems comes
>> from improper packaging. E.g. maintainer forgot to obsolete, so during upgrade
>> user get file conflict. Once these problems are reported and fixed the upgrade is
>> without problem.
>
> I'd strongly say "NO" to this. Not because I would have a problem with
> people doing non-fedup upgrades (I tend to upgrade my machines with yum
> myself, too). However, making this officially supported, and advertising
> this as a feature appears to be the wrong move to me.
>
> The thing is that doing on-line updates only works for stuff you can
> restart, and that doesn't mind that things are not atomically
> updated. However, much (most?) of our code isn't like that. Anybody who
> tried to update the Firefox RPM while it is running knows that this
> doesn't end well, and you frequently have to manually kill firefox to
> get it back into a usual state.
>
> Doing manual on-line upgrades with "yum distro-sync" is a fine
> thing to do, but this requires people to understand that things might go
> wrong, and requires a certain skill set from people so that they know
> what to do if things go wrong (like for example knowing how to kill
> firefox from the command line). But by making this an officially
> supported feature fedora would suggest this as something that would work
> for anybody, without any additional knowledge, and Fedora would have to
> deal with the additional support work/bug burden this creates.
>
> It's OK if an RPM for this enters the archive, it's OK if people who
> know how to fix their machines use this, it's OK if people suggest this
> as hidden functionality. But I think it would be a big mistake for
> Fedora to advertise this as official feature, and to accept the support
> burden this creates.
>
> Fedora doesn't have unlimited resources, we have more than enough bugs
> to fix anyway, making online updates an officially supported feature
> would amplify this disparity.

I, speaking for the stuff I'm involved and maintain, will certainly
not work on things to make online upgrades work correctly, if they
don't for whatever reason.

It's a huge lie to pretend we can reliably do this, and just a
I-hope-it-will-work-out thing not based on the technical reality.
Anybody who claims this can and will always work flawlessly as a
general model, seems not to understand the problems well enough.

We all do these kind of updates ourselves, sure, and we surely don't
want to make that impossible in the future; but it's nothing I
personally would *ever* want to *support* on other people's systems.

There is a reason we partly switched to offline updates now, it can at
least work in the theory behind it, unlike the online updates. Please
never try to *support* that officially, it cannot and will not work
out.

Thanks,
Kay