Does anyone have any experience with backing up servers that have been failed over to DR hardware in a DR scenario?

For example, one of our production Oracle servers has a DR "twin" with a different system name. In a disaster scenario, the storage is failed over to the DR hardware and the twin is reconfigured to "become" the production server, with the original production IP and system name etc.

The problem I see with this is that in order to back up the twin after failover, I'm going to have to re-register the server, which in turn will create a new instance of the client in Avamar. So I'll end up with two versions of the production server name in Avamar.

I suppose the question to ask is "what does Avamar use to identify an individual client"? For example, I've modified IPs before and the client has been able to re-register without duplication. However if I change the system name Avamar can no longer "see" the client, and when it's re-registered it creates a new client instance.

Thanks.