You get incremental backups (snapshots) by using
--link-dest=DIR hardlink to files in DIR when unchanged
To use this you pass in the previous snapshot location as DIR and use a new destination directory for the current snapshot. This creates hard links in the new snapshot to the files which were unchanged from the previous snapshot, so only the new files are transferred, and there is no duplication of data on disk (for whole-file matches).
This does of course require that all of the snapshots exist in the same filesystem, since you cannot hard-link across filesystems.
koala@programming.dev 5 hours ago
Ah, I didn’t know of this. This should be in the linked article! Because it’s one of the ways to turn rsync into a real backup! (I didn’t know this flag- I thought this was the main point of rdiff-backup.)