Disclosed is a method and apparatus for replicating a data volume using a network appliance. In one embodiment, a first node transmits a first write-data transaction to a first data storage system and to the network appliance. A second node transmits a second write-data transaction to the first data storage device and to the network appliance. The network appliance transmits the first and second write-data transactions to a third node via a communication link for updating a replica of a data volume. The data volume is stored in the first data storage system and is updated with first and second data contained in the first and second write-data transactions, respectively. The replica of the data volume is stored in a second data storage system and is updated with the first and second data.