Proposed F19 Feature: Fedora Upgrade - using yum

[Adam Williamson]

On Mon, 2013-01-28 at 14:01 +0100, Gerd Hoffmann wrote:
>   Hi,
> 
> > If a fedup upgrade can go offline for a lengthy, but uncertain, amount
> > of time, then the lack of feedback is worrying.  You can't hold your
> > breath for 25 minutes, you don't know when to conclude that you have a
> > serious problem that will require help from the data center staff, and
> > you don't have any idea where the process went off-track.
> 
> I actually like fedup, and I guess I'll go stop using yum for upgrades
> if I can use fedup instead.
> 
> I've seen anaconda upgrades (be it dvd-based or via preupgrade) blow up
> multiple times and settled on using yum instead.
> 
> But fedup is different.  Even though it is still quite young I actually
> trust it to get things right.  It fetches all packages, then does a
> transaction check and if that fails it says so and allows you to fixup
> stuff before actually kicking the upgrade.  Remove orphaned packages
> causing dep issues, cleanup disk so filesystems have enough free space
> to run the transaction, whatever is needed.
> 
> That is very simliar to how you handle issues when upgrading using yum.
> 
> Once everything is settled and fedup says "reboot to upgrade" you can be
> pretty sure that it will work fine.

Well, the other thing fedup does - and the other reason it's necessary
compared to a simple online yum upgrade - is provide a mechanism for
pretty much any package to hook in pretty much any action to be
performed as part of the upgrade. To be sure of what's going to happen
during a given fedup transaction, you should also check what scripts are
going to get fired as part of the upgrade. In F18 I'm not sure there are
any, but this is the kind of mechanism we would use, fr'instance, to
switch the default bootloader as part of an upgrade in future, if we
decided we wanted to do that again. The kind of stuff that can't be done
in %pre/%post etc.
-- 
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | identi.ca: adamwfedora
http://www.happyassassin.net