I've got several VMs (Windows Server 2003-2008 R2, application servers, Exchange, SQL, small file servers) residing on ESXi 4.1 hosts. We recently purchased a Data Domain system allowing us to backup our data and have it deduplicated, compressed, and stored at two physical locations. The NetWorker server is connected to the vCenter server allowing for auto-detection of the VMs and backing them up via VADP.
Reading the various manuals for NetWorker (v7.6.3) implementation in a VMWare environment, they reference setting up VADP on the Storage Node in order to maximize minimize the network hops involved in a backup process by running at system bus speed between the VADP appliance and the Storage Node.
In the backup configuration in the NetWorker Admin console, there are options to use a Storage Node or to backup directly to the DataDomain system via the NetWorker server. What are the benefits to backing up using a Storage Node versus directly through the NetWorker server?