That's also the least interesting part of comparing a ZFS backup to rsync/rclone: The rsync way is to crawl the entire tree being backed up to diff over the ne

That's also the least interesting part of comparing a ZFS backup to rsync/rclone: The rsync way is to crawl the entire tree being backed up to diff over the network then copy the differences. Because of snapshots, ZFS already knows all the changes that occurred between snapshot A and snapshot B, and (provided state up to A has already been backed up) can update the backup by pushing all changes between A and B as one big binary blob without having to scan or diff anything.