Comment # 95 on bug 1094762 from Carlos Robinson

I forgot about this:

(In reply to Franck Bui from comment #44)
> (In reply to andreas bittner from comment #43)

...

> > What comes to my mind maybe is, is it possible that non-rebooted machines
> > that e.g. had updates on 42.3 level (systemd and other stuff lately, not yet
> > replaced and activated all files in use, e.g. non rebooted yet) and then
> > going for a zypper dup with repositories swapped over to 15.0 URL addresses
> > 
> 
> Hmm is this scenario supported ?
> 
> I mean should such upgrade are supposed to be done offline ?

Yes, IMHO, it is better to do them offline, but yes, that scenario is
supported, and I think that it is more popular in fact.