Exchange 2010 DAG question

Was wondering if anyone could help, I’m sure I’ve just got a simple setting wrong or maybe my DAG is just to simple at this time.

We’re migrating to O365 and our Ex2010 environment’s DAG is down to just one DB across two servers. We’ve used CommVault up to this point but maintenance is running out in May so am trying to get this simple DAG running on Avamar.

What I’ve done is created a dataset with the Exchange VSS and a group with the two servers in it, basically like the docs say to do it. Only thing I’m running into is, when a backup runs both servers are backing up the one DB, seems like one server backs it’s copy of the DB up and the other backs up it’s copy, so both the active and passive copies are both being backed up by their respective owners.

I noticed when this setting, “Set when backup occurs on clustered or DAG systems” = “Always”, is when both servers back up both copies of the DB(Active and Passive). If I change that setting to “Replica (passive) writer only”, the server with the passive copy backs up the passive copy, but the other server fails with two errors, “Could not expand targets correctly” and “Unable to complete backup”.

I figure the reason is obvious in that that server has no passive DB to backup so errors out. Is this just a case where I have to live with the errors, since being I only have one DB, thus only one passive copy, that one of the servers is always going to fail?


Leave a Reply