1. A method comprising: in response to a first stream of writes to a first non-volatile memory system, generating a second stream of writes for a second non-volatile memory system; and coordinating replication of data stored in the first non-volatile memory system, comprising embedding at least one command in the second stream of writes to create a synchronization point for data storage in the second non-volatile memory system in response to at least one corresponding command in the first stream to create a synchronization point for data storage in the first non-volatile memory system.