When will Fedora work again?

[Patrick O'Callaghan]

On Tue, 2009-03-10 at 20:12 +0000, "Jóhann B. Guðmundsson" wrote:
> On 03/10/2009 03:38 PM, Patrick O'Callaghan wrote: 
> > On Tue, 2009-03-10 at 11:01 +0000, Frank Murphy (Frankly3D) wrote:
> >   
> > > Antonio M wrote:
> > > 
> > >     
> > > > I confirm that rawhide is working here with intel integrated card on
> > > > my laptop after this morning updates (mobile GM965/GM960 integrated
> > > > graphic controller)...be careful during updates and have at hand a
> > > > bunch of working packages so you may revert in case of  failures.
> > > >       
> > > Then would it be time for some sort of "rollback" utility,
> > > so if "yum update something" breaks, maybe  : yum --rollback something
> > >     
> > 
> > That's been discussed before. It's fantastically hard to do, short of
> > snapshotting the whole system.
> > 
> > poc
> > 
> >   
> Why dont you just enable keepcache in yum.conf and do rpm -Uhv foo.rpm
> --oldpackage
> if you need to go back a version ?

For a single package yes, but "rolling back" a full yum update can be
more complicated than that. For one thing, you have to remember which
specific version of each updated package was installed before the update
(which may work if keepcache was enabled a long enough time ago,
otherwise not). Plus some packages may not even roll back correctly
without manual intervention, e.g. evolution recently changed its index
database format to SQL. The new version can read the old files from
previous versions, but not vice versa, so you'd need specific rollback
code in every package with this kind of problem. Snapshots may be the
best way to go, but of course they'd need a COW filesystem at minimum.

poc