Replication Process

All replication infrastructure components engaged in replication make up a data pipe. VM data is moved over this data pipe block by block, with multiple processing cycles.

The replication process is performed in the following way:

1. The source-side Data Mover Service communicates with the target‑side Data Mover Service to begin data collection.
2. The source-side Data Mover Service accesses the VM image and copies VM data using one of VMware transport modes, as prescribed by the backup proxy server settings. During incremental job runs, the Veeam Data Mover Service retrieves only those data blocks that have changed since the previous job run.
   While copying data, the source-side Data Mover Service performs additional processing — it consolidates the content of virtual disks by filtering out zero data blocks and blocks of swap files.
3. In cases when VMware CBT is not available, the source-side Veeam Data Mover Service interacts with the Veeam Data Mover Service hosted on the backup repository to obtain replica metadata. The source-side Veeam Data Mover Service uses this metadata to detect blocks that have changed since the previous job run.
4. Copied blocks of data are compressed and moved from the source-side Data Mover Service to the target-side Data Mover Service.
5. The target-side Data Mover Service decompresses replica data and writes the result to the destination datastore.