I think this should be the sequence
1. Take snapshot, this should return a VirtualMachineSnapshot object
2. Open the base disk, not the one with the suffix.
3. Use the snapshot objects config info to create a VM in the replication server
4. Read/write data from the base disk.
But since you say it is a replication, you got to figure out how to transfer the data that gets written in to disk after the snapshot.
./Siva.