On 22 November 2011 14:42, C Anthony Risinger <anthony@xxxxxxx> wrote: > On Nov 22, 2011 1:30 PM, "Bernardo Barros" <bernardobarros2@xxxxxxxxx> > wrote: > > > > If I still may: > > > > roll-back and reproducible configuration was already proposed in the > past? > > > > The idea raised by Nix devs was the a purely functional approach was a > > way to implement it. Of course people can have similar ideas with > > other techniques. > > > > If it a very practical question because I'm sure all Arch users in > > some point or another had to do a roll-back after a complex system > > update, and then they find themselves in a difficult situation to > > figure out how to revert all those changes. > > > > Pro Audio users, for instance, might want to have their system > > configuration in a state just before the change that broke lv2 support > > on Ardour. > > > > Nix approach may be not the only one, but their ideas let people see > > the difference between same packages build with different libs, or > > know to set a exact system configuration more easily. > > The only clear way to achieve clean rollbacks is to snapshot at the FS > level ... otherwise things get real complicated, real fast. > > Some packages are one-way only, eg. Pacman 3.5 upgrade to DB, and > "rollback" means saving the original, etc ... > > As already touched in the thread, btrfs makes this trivial. > `mkinitcpio-btrfs` will provide 95% of what's needed already. The hook > could definitely use some love but it fulfills the suggested use case > nicely, and also allows for comparison between snapshots. > > C Anthony > Honestly I don't know how this topic got so off-topic so quickly! I think it is obvious that pacman will not get rewritten in Haskell, so lets just stop talking about that - arguing over languages is like arguing over window mangers, cmon people! Secondly, I agree that snapshots must be done at a system level. It does not make sense to re-implement something that is already being done better by the file system. I think the OP had some ideas about rolling changes back, I don't think he was really familiar with ARM which handles most of that he was worried about. Remember, you gotta KISS it or else you'll miss it! :-)
