You have a need to preseed the replica VM so that the replication job will only replicate the changes when the replication job runs.
For more current information on this topic, please refer to Knowledge Base Article 83953
For the replication job to replicate only the changes the vzmap needs to present in the VM directory on the target host (or in the VAs for ESXi host). The vzmap file is created during the first replication run and is updated as the replication job is ran. If no vzmap is present a full replication is going to be run. Backing the VM up and restoring the VM on the target host is not going to allow you to preseed the VM. Please see the resolution section for the proper way to preseed a replica VM.
Please follow the steps below to properly preseed the replica VM. A couple different options exist.