If a set of files (several GBs big each) and each changes slightly every day (at random places, not only information appended at the end), how can it be copied efficiently? I mean, in the sense that only changed parts are updated, and not the whole files. That would mean the difference between copying some Kb here and there or some GBs.
Backup – How to Back Up One Big File with Small Changes
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Best Answer
The rsync program does exactly that. From the man page: