# Replication

This section provides a step-by-step description of a VMware virtual machine replication process implemented in Veeam Backup & Replication.

In many aspects, the replication initialization phase is similar to the initialization phase of the backup process. Veeam Backup & Replication starts the necessary processes, builds the list of VMs to replicate, assigns backup infrastructure resources for the job and starts Veeam Data Movers on two backup proxies (source and target) and the backup repository that is used for storing replica metadata.

Next, Veeam Backup & Replication performs in-guest processing tasks, triggers VM snapshot creation, registers a replica VM on the target host and performs data transfer from the source host and datastore to the target host and datastore. The source and target proxies can use one of 3 available data transport modes for reading data from source and writing data to target.

This diagram illustrates the replication process with the NBD transport mode used for reading and writing VM data. For examples of the Direct SAN/NFS Access and HotAdd transport modes, see the “Backup Anatomy” section above in this Appendix.

![](/files/-MA6eMdb1ErVd-7kJyoO)

Note that Veeam uses backup repository to store replica metadata.

The following diagram illustrates a possible placement of the Veeam Backup & Replication components in a distributed environment, with a WAN link between the production and DR sites.

![](/files/-MA6eMdcVJ8_exz4k_3o)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://old.veeambp.com/anatomy/replication.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.