Keep in mind that this post is three years old. A lot can change in three years.
There was some confusion in terminology and acronyms early on. What was eventually decided is that “EBR” would refer to the vSphere plug-in and “VBA” would refer both to the solution as a whole and to the virtual appliance. VBA is similar to VDP but there are some significant architectural differences.
The question of internal storage was addressed earlier in the thread, where I mentioned that it’s possible to write backups directly to internal storage but the original question specifically asked about writing the backups to Data Domain.
While it is possible to use VBA’s internal storage, this is against the best practices published in the NetWorker VMware guide (at the time the original post was written, these best practices had not yet been established). The “checkpoint backup” action can be used to back up data stored on a VBA. However, the checkpoint backups are in a format that NetWorker can’t understand on its own so you would have to do a DR recovery from the checkpoint backup in order to run restores of the actual VM data. The VBA DR procedure is fiddly and error-prone. You’re far better off writing to Data Domain using DDBoost and taking advantage of cloning, automated resurrection, etc..
Of course at this point, you’re probably better off moving to vProxy if you can. Fewer moving parts means less that can go wrong.