I have a large number of stateful servers that use Yum for package management. I am interested in a general automatic process for rolling them back to a historical state.
Usually, enabling the correct repo and using distro-sync would be sufficient, but packages which are marked with Obsoletes: can break this; Yum will refuse to automatically downgrade to the obsoleted packages, and a user must manually say that they want to remove the obsoleting package and install the original.
Is there a general way to avoid this issue, other than simply banning Obsoletes:? I could try to maintain a list of packages which should be installed for every historical version, but that seems heavyweight, and also has complexity with autoremoving unneeded dependencies (I'd have to implement logic for removing everything that I don't pin).