[nemothekid]

I don't believe you can have a mixed Scylla/Cassandra cluster. In our case we cloned our drives and started a whole new cluster with Scylla. When we were happy with Scylla and done the appropriate testing, we shutdown the Cassandra cluster.

[duarten]

[Scylla employee] Indeed a mixed cluster isn’t supported, since the inter-node protocols are incompatible.