The original post that introduced this idea into general public: http://www.mikerubel.org/computers/rsync_snapshots/ http://www.mikerubel.org/computers/rsync_sn

The original post that introduced this idea into general public: http://www.mikerubel.org/computers/rsync_snapshots/ http://www.mikerubel.org/computers/rsync_snapshots/ I’m sure others will chime in that they used hard links like this before then, however as noted in that page, it’s the one that made it popular enough that rsync was updated to support the idea natively.