Unable to select member servers for an Exchange DAG client

DAG member servers are missing or appear grayed out in Exchange DAG client properties.

Symptoms

DAG member servers are not listed or unselectable when appearing in grayed out state.

If the member servers appear grayed out, you will see logging simlar to this in EvMgrS.log on the CommServe:

### [HasExDbAgentInstalled]: Get client Id failed

Causes

Exchange Database Agent is not installed or client member server hostname in CommCell Console does not match hostname contained in Active Directory.  Mis-matched hostname issue is usually due to using the member server's short name vs the Fully Qualified Domain Name (FQDN) during installation of the Exchange Database Agent.

Resolution

To resolve, first verify the Exchange Database agent is installed on the member server.

Next, verify the DAG member server hostname that appears in client properties matches the DNS hostname used in Active Directory.

Step 1:  Get the DNS Hostname contained in Active Directory

Using Powershell:

PS C:\prog\PowerShell> Import-Module ActiveDirectory PS C:\prog\PowerShell> Get-ADComputer -Filter 'ObjectClass -eq "Computer"' | Select -Expand DNSHostName

Step 2: Compare and edit Host name in CommCell Console's Client properties

1. In the CommCell Console, expand Client Computers, right-click on the DAG Member Server client, and select Properties.
2. In the Properties dialog box's General tab, compare the hostname that appears to the DNS hostname obtained in Step 1.  If the names are different, click Edit and change the Client hostname to match the Active Directory's DNS hostname.
3. Save the changes and retry adding member server to Exchange DAG client.