传输模式

A transport mode is a method that is used by the Veeam Data Mover to retrieve VM data from the source and write VM data to the target. Job efficiency and time required for job completion greatly depend on the transport mode.

For data retrieval, Veeam Backup & Replication offers the following modes (starting from the most efficient):

• Direct storage access
• Virtual Appliance (HotAdd)
• Network

The Veeam Data Mover responsible for data retrieval runs on a backup proxy. Correspondingly, the transport mode can be defined in the settings of the backup proxy that performs the job.

When you configure backup proxy settings, you can manually select a transport mode, or let Veeam Backup & Replication select the most appropriate mode automatically. If you use automatic mode selection, Veeam Backup & Replication will scan backup proxy configuration and its connection to the VMware vSphere infrastructure to choose the optimal transport mode. If several transport modes are available for the same backup proxy, Veeam Backup & Replication will choose the mode in the following order: Direct storage access > Virtual appliance > Network.

The selected transport mode is used for data retrieval. For writing data to the target, Veeam Backup & Replication picks the transport mode automatically, based on the configuration of the backup proxy and transport mode limitations.

Veeam Backup & Replication leverages VMware vStorage APIs for Data Protection (VADP) for all transport modes except for backup from storage snapshots, the direct NFS transport mode and the virtual appliance transport mode. VADP can be used for VMware vSphere starting from version 4.

Applicability and efficiency of each transport mode primarily depends on the type of datastore used by the source host — local or shared, and on the backup proxy type — physical or virtual. The table below shows recommendations for installing the backup proxy, depending on the storage type and desired transport mode.