Hi

Might sound hard to believe but my org has really never looked at using DAG. We're in the middle of a VMWare to HyperV migration, and I was thinking of using a DAG to get the mailboxes over to a new HyperV VM, instead of migrating the entire VM (which will take a very long time).

So, can I create a DAG and pick the databases I want in it ? Or is a DAG based on a per server base meaning all DB's on a server are in a DAG if you add the server to a DAG ?

And can I at all put existing DB's in a DAG or can I only add them when I create a DB ?

Also, can DAG's work across different Exchange versions ? Meaning one DAG member is E2010 and the other E2013 ? Probably not, but this would be nice too.

Greetings
Richard

• Edited by Richard Willkomm 15 hours 2 minutes ago

Hi,

So, can I create a DAG and pick the databases I want in it ? Or is a DAG based on a per server base meaning all DB's on a server are in a DAG if you add the server to a DAG ?

You simply need to add the server to the DAN. then create additional copies of the DBs.

Also, can DAG's work across different Exchange versions ? Meaning one DAG member is E2010 and the other E2013 ? Probably not, but this would be nice too.

You cannot have DAG across different versions. Even in same version it is highly recommended that DAG nodes run the same ServicePack/RollupUpdate.

Hope that help.

• Proposed as answer by Amine.G 10 hours 12 minutes ago

Adding selective databases to the DAG isn't a problem. Although the event viewer will have errors about the databases outside of the DAG being outside of the high availability scope.

Personally though, I would build a new Exchange server then move the mailboxes, rather than the method you have proposed. This will give you a clean database, clean server. It will allow you to change versions or Exchange builds, or even the host OS (in a DAG everything has to be identical).

Simon.

Hi Richard,

If you want create DAG to move mailbox, I recommend use database portability to move mailbox database between Mailbox server within same version and same organization. For your reference: https://technet.microsoft.com/en-us/library/dd876926(v=exchg.150).aspx

If you want to upgrade Exchange version, please try Simon's suggestion to install new Exchangeand deploy batch move mailbox.