[Mageia-dev] Proposal: Updating released versions (long post)

Fri Oct 8 21:58:45 CEST 2010

Marc Paré wrote:
+> So, as to your proposal, I am in agreement with it. Maybe a suggestion
+> (more of a question), seeing as the issues have to deal more with the
+> dependencies of a "roll-back", what if, "Backports" would install,
+> somehow the software updates in a self compartment kind of way (sorry
+> my language terms may not be descriptive enough).
+
+Michael hinted at that, either taking a copy-on-write (brtfs) copy of
+the user's system for later restore, or having users install the update
+on a VM copy of their system, but the image thing is good for only one
+update at a time, and I don't think most users are going to re-install
+in a VM to test a new package.  There really isn't a good way to install
+in a "sandbox".
+
+>
+> Users know that repositories are activated and some are not at the
+> time of install. I think that most users have a faint idea of this.
+> But if Backports were to be used more at the user level, what is
+> clear, is that, there should be a roll-back feature. If the roll-back
+> feature, as a normal course of rolling-back will or could remove other
+> softs due to dependencies, then maybe possible option would be to have
+> the "Backport" software installations install all dependencies in such
+> a way as to isolate them from the larger distro packages. This would
+> in effect could make a secondary related-dependency file on the
+> system. Then if a roll-back were done a Backported software package
+> only the associated dependencies would be deleted.
+>
+> Could this be done?
+
+Wherever this can be done, it usually is.  Multiple versions of
+libraries can coexist in Linux, so if the new version requires new
+libraries, there's no conflict.
+
+The dependencies that cause problems are, for example,  the situation
+where you can only have one of a certain service provider and its users
+are bound to it by an API which changes between the release version and
+the new version you want to install.  For example, if A, B, C, D, E all
+use F, and the new version of C has been changed to use the
+(incompatible) API of the new version of F, you'd have to install all 6.
+
+
+