Every time I run rsync to backup a blockchain, it starts from the beginning and tries to sync the whole thing, every time, even though there may only be a few blocks worth of data that is new. The rsync man page says, "It is famous for its delta-transfer algorithm, which reduces the amount of data sent over the network by sending only the differences between the source files and the existing files in the destination," but I cannot figure out how to get it to only update the new info that has been added to the blockchain. As the chain is very large, it is ridiculous to keep copying the whole thing every day. Can rsync backup only new data, and if so, how can I tell it to do so?

This what I am using:

> rsync -avz --exclude-from=/exclude/file -e ssh /from/file [email protected]:/backup/file