[Yum] history, tagged installations, and downgrade

[David Farning]

> Obviously I think that this would be a great boon to development sites
> e.g. the Mozilla site.  One reason everybody is fairly cautious about
> upgrading is the likelihood of something breaking and the PITA of
> backing off if it does.  Yum could utterly and forever remove this as a
> PITA and indeed make it easy.  (The ability to lock clients to tagged
> full revision sets would incidentally be of great benefit to e.g. banks
> and hospitals as well, as they often have to undergo a federally
> mandated process of testing and approval to change ANYTHING in their
> underlying systems).
> 
>    rgb

I've also been pondering the ability to do rollbacks.  The hurdle that I
keep stumbling against is packages that don't play well with other. 
Config files are nasty.  Rpm -U will often(sigh)  make a backup of
configs.  The rollback mechanism needs to deal with the possibly changed
configs.  

hmmm This is getting well beyond yum, but if you also committed /etc/**
at the rollback points.... 


Thanks
Dave Farning