If you are configuring Exchange 2013 Mailbox DAG, you must pre stage DAG Cluster Name Object (CNO) in Active Directory. CNO is an active directory computer object that simply provides an identity to DAG and cluster. In this post, I will show steps to create CNO in Active Directory.
Pre Stage DAG Cluster Name Object (CNO) in Exchange 2013
Step 1: Logon to Domain Controller and open Active Directory Users and Computers snap-in.
Step 2: Right-Click Computers OU and choose New > Computer. Make sure you’ve enabled advanced features. in Active Directory Users and Computers.
Step 3: Type the Computer name. Computer name will be same as DAG name, because that’s what we are creating. Click OK to save.
Step 4: Open properties of this new computer account. Select Security tab. Under Groups or user names, click Add.
Step 5: Click Object Types.
Step 6: Check Computers box and click OK.
Step 7: Add Mailbox server and click OK.
Step 8: Select computer account and give full permission. Click OK.
Similarly, add and provide full permission for Exchange Trusted Subsystem group to the computer object.
Step 9: Now right-click the computer account and click disable. Windows Failover Clustering will not work if the computer is not disabled.
Step 10: Click Yes on the warning.
Step 11: The account is disabled. Click OK.
Now, you can go back to EAC, and create DAG.