Feature request: Store diffed files separately.

[Ben Wilber]

Hello all,

I'm going to feel dumb if rsync can already do this, but I honestly
haven't found anything to indicate that.  I would like to be able to
store diffed files in a separate directory on the receiver so it makes
doing an incremental backup easy and efficient.  Let me explain:

Day 1: take a full backup of a directory: rsync -r ./source/ ./dest/
Day 2: Diff the contents of ./source/ and ./dest/ and store only the
new/modified files in ./incremental_day1
Day 3: Diff the contents of ./source/ and ./dest/ and store only the
new/modified files in ./incremental_day2
etc.

This way to restore a backup of Day 2 just do: rsync -Pvr
./incremental_day2 ./dest/ # But make the updates to ./source/ instead
so you can preserve existing backups.  Does this make sense?  I
thought something like this might be useful since your on-going
incremental backups aren't storing unchanged files again which will
save space.

Ben Wilber