Scale-out Backup Repository
Scale-out Backup Repository is, as the name implies, a scale-out architecture based on multiple Veeam backup repositories. Repository datamovers, regardless of whether they are integrated or are in an external gateway, are used in a SOBR as master and slave repository datamovers.
During backups, the master datamover is always started where the write is happening. During restore, the master is always started where the VBK is located, as blocks are most likely retrieved from this location due to Data Locality policy being the recommended setting for most deployments.
A master datamover is the only repository datamover receiving data from a source datamover (a proxy or agent in a backup job, or a source repository in a backup copy job). A master datamover is able to communicate if needed with other slave datamovers to retrieve their data.
Network considerations
As in any scale-out solution, careful design should be applied to the network. Communications between the different data movers may increase network consumption, regardless the policy in use or the specific design of the scale-out architecture. When using Scale-out Backup Repository, 10Gb networks are the recommended minimum.