Setting up a new Exchange 2013 DAG
Our existing MS Exchange setup uses a Database Availability Group (DAG) to replicate the mailbox databases to another Exchange 2010 server located in another office. Recently we installed Exchange 2013 to replace our existing Exchange 2010 implementation and needed to setup a new DAG for the 2013 servers. Under 2012 the permissions for computer objects have changed slightly. When a DAG is configured it creates a Cluster Named Object (CNO) which is basically just a computer account for the DAG. If you are running Exchange 2013 on a 2012 server though the wizard is unable to create this object correctly because of the new permissions and instead you need to pre-setup the CNO in active directory so that the DAG can add the servers you assign. Pre-stage CNO (Cluster Named Object) Open Active Directory Users and Computers. Expand the forest node. Right-click the organizational unit (OU) in which you want to create the new account, select New , and then select Computer . ...