git-annex keeps track of what file is where, including any duplicate copies you wish to keep on other storage mediums. If I want some file I archived, git-annex

git-annex keeps track of what file is where, including any duplicate copies you wish to keep on other storage mediums. If I want some file I archived, git-annex will tell me which external disk it's on (and it can do S3 and some other online storage mediums too). rsync keeps track of nothing between runs. I find it really useful for archiving large files - an entirely different use case than git.