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Delta Compression for Linux Security Patches?
cperciva asks: "For people without fast internet connections, it is often impractical to download large security patches. In order to avoid to reduce patch sizes, some operating systems -- starting with FreeBSD over a year ago, and recently followed by Mac OS X and Windows XP SP2 -- have started to use delta compression (also known as binary diffs, which constitutes a portion of my doctoral thesis), and can often reduce patch sizes by over a factor of 50. In light of the obvious benefits, I have to ask: When will Linux vendors follow suit?"
Certainly for your primary commercial auto-updated Linux distributions it does, but for anything else it usually doesn't. What makes more sense (because it's easier) is breaking up media and programs, and distributing them separately so you don't have to update one when you update the other. Some projects do this already, and even package their sources this way.
Personally I'd prefer to see binary distributions move to a model of using something like cvs, so you can just do a cvs up (or equivalent) and update everything. Some files would have to be marked to always be overwritten, while config files would be merged. This solves both your differential update problem (if the right system is used - I'm thinking that's pretty much not CVS but I don't know if there's a way to make it do all of that - CVS doesn't handle binaries amazingly intelligently from what I understand) and your updates in general. Plus, you can use it both for source and binary updates.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"