When backing up a Scylla cluster (or cassandra for that matter) I understand that its best practice to take a snapshot of every node.
However if I have a 6 node distributed cluster spanning 2 datacenters with RF3 in each datacenter for the keyspace I want to back up would I logically be able to back up the keyspace on just one of those nodes as there is a full copy of the data on each one?
The quick answer is yes, each replica owns 100% of the range when the replication factor and number of nodes in the DC are the same.
However, 100% ownership does not guarantee that each replica (node) is consistent given the distributed architecture of a Cassandra cluster.
So, yes you can have hypothetical discussions about whether all data should be on each node but when talking about production systems, it isn't something you should bet your career on. We recommend you backup all nodes in the cluster as per the norm. Cheers!