Summary
The SMEX installer cannot detect clusters as well as the Exchange Virtual Server (EVS) and other nodes while installing SMEX on an Exchange 2010 server where the DAG feature is enabled.
Details
Installing SMEX with DAG capabilities is similar to installing Hub Transport/Mailbox Servers/Clustered Mailbox Servers. Administrators need to specify all the nodes in the DAG where SMEX needs to be installed.
Unlike other clusters, DAG does not have Exchange resources thus the installer cannot detect it as a cluster.
The servers can be identified or added when the “Please specify the server(s) to install to” dialog box appears.