The Network mode can be used with any infrastructure configuration. In this mode, data is retrieved via the ESX(i) host over LAN using the Network Block Device protocol (NBD).
The Network mode is not a recommended data transport mode because of low data transfer speed over LAN. To take the load off the LAN, Veeam Backup & Replication provides two alternative modes: Direct Storage Access and Virtual Appliance. The Network mode is the only applicable mode when the backup proxy role is assigned to a physical machine and the host uses local storage.
The process of data retrieval in Network mode includes the following steps:
- The backup proxy sends a request to the ESX(i) host on which the processed VM is registered to locate the VM on the datastore.
- The ESX(i) host locates the processed VM on the datastore.
- Veeam Backup & Replication instructs VMware vSphere to create a VMware vSphere VM snapshot, copies VM data blocks from the snapshot and sends them to the backup proxy over LAN.
- The backup proxy sends the data to target.
Veeam Backup & Replication processes VM disks one by one or in parallel, depending on selected data processing settings. If VM disks are located on different storages (for example, on the SAN and local storage), Veeam Backup & Replication uses different transport modes to process VM disks. In such scenario, it is strongly recommended that you select the Failover to network mode if primary transport modes fail or are unavailable option when configuring the mode settings for the backup proxy.