Installing DAG on exchange Server 2016

Before we can create the DAG we need to setup the Witness Server Machine
Add “Exchange trusted subsystem” to Administrator Group on witness machine

Now, Open Exchange Admin Center, go to Server and Open “Database Availability Group”, click on the + icon to create a new DAG.
Type the name of the DAG, and witness Server, you can keep the Witness directory empty the same will be created automatically.
NOTE: Post Exchange 2013 SP1 onward we can setup a IP Less DAG and type in IP address Field.

Now the DAG will be Setup, we can verify the same from the ECP and from the powershell.
Now lets add the Server to the DAG.
While I was trying to add the Server to the DAG, I got the error message, “The fully qualified domain name for node 'DAG01' could not be found.”
To fix this error I just had to disabled to CNO DAG01 from Active Directory.
Now after that I got the below Error.
A server-side database availability group administrative operation failed. Error The operation failed. CreateCluster
errors may result from incorrectly configured static addresses. Error: The computer account 'DAG01' could not be
validated. Access was denied. Check that the current user (NT AUTHORITY\SYSTEM) has permissions to create computer
accounts in the domain or to claim the computer account.
To fix this issue I had to give full permission to “Exchange Trusted Subsystem” on CNO DAG01

After that I was able to add the both the server to DAG.
Now Lets Create a Database Copy,
to create a database copy, from ECP select the Server, databases, and then use the more option to create the databse copy, below wizard will be open,
Click on Browse and Select the server for database copy.
Log seeding will be started.
It will take some time to finish the copying the logs.
once logs copying finished we can close the wizard.

Conclusion: in this article we setup DAG on the Exchange server 2016, and setup database copies.