An apparatus and method to replicate one or more files between non-symmetric storage systems are disclosed. The method supplies a first storage system comprising a first configuration, a first volume, a first file system, and a first replication appliance comprising first replication appliance memory. The method further supplies a second storage system comprising a second configuration, a second volume, a second file system, and a second replication appliance comprising second replication appliance memory, where the first configuration differs from the second configuration. The first storage system receives a dataset, writes that dataset to the first volume as a first file. Applicants' method then replicates the first file to the second volume as a second file, and maintains in the second replication appliance memory a second replication appliance mapping associating the first file with the second file.