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

Sat Oct 9 05:45:16 CEST 2010

Frank Griffin a écrit :
+> Marc Paré wrote:
+>    
+>> Thanks. So this thread is to see if there were a possibility to
+>> programme a more efficient roll-back option so that it would be more
+>> "aware" of the previous "dependencies" needs for the previous version.
+>> Having "double dependencies" is not so much of a problem, it is the
+>> rollback to a previous version where the dependency confusion may
+>> occur, and, ONLY, if an upgraded type of "dependency" thread had been
+>> installed. (Sorry I may have used the wrong terms in the last sentence).
+>>      
+> Well, sort of.  It's not an issue of efficiency, but of convenience and
+> just making it possible to do without resorting to manual use of the rpm
+> command.
+>
+> The rpm command "knows" that a new version replacing the old version
+> supplies the same things that the old one did, so it will quietly allow
+> the upgrade.  It will also do what we need, i.e. go the other way and
+> replace a newer version with an older one if you use the --oldpackage
+> keyword.  We just need urpmi to support its use
+
+One thing that could facilitate this process, if the computer has a lot 
+of free disk space, is to rename the files being removed (copying the 
+configuration files), instead of erasing them.  Although they will 
+probably have to be erased eventually, since no computer has unlimited 
+disk space.  Keeping them long enough that a roll-back is no longer 
+probable could be workable.
+Then a roll-back could be done very quickly, since the files are already 
+on disk, and presumably reliably.  Of course, if new data has been 
+entered, and the format has been changed, this could be problematic.
+Note that configuration files that have been changed from the 
+installation default are often already saved.  (Generally ".old" is 
+appended to the configuration file name, sometimes ".new" to the new 
+configuration file.)
+This of course adds the maintenance task of removing the old files at 
+some point - it could be done automatically according to some criteria, 
+or the user could have to do it manually, perhaps after being prompted 
+about it.
+
+(This rollback capability occurs with Microsoft products.  The saved 
+files are only removed manually, on user initiative, which partly 
+explains the bloated size of a Microsoft installation over time.)
+
+If renaming-instead-of-deleting is implemented, perhaps a "do not keep 
+old program files (useful if limited disk space)" checkbox option would 
+be useful for computers with less free disk space.
+Of course how much disk space is usable to save old programs on a 
+computer depends on the disk space usage for other purposes over time.
+
+my 2 cents :)
+
+- André (andre999)
+
+