I received some questions on Single Copy Clustering for Exchange 2007 that I wanted to share with everyone.
1. In SCC with geocluster the cluster mailbox server name is maintained by IP address is not. IP address and DNS propagation are essential in the geocluster. We recommend TTL for the host record be a value of 10 minutes.
2. Configure for missed cluster heartbeats. Set for all nodes for 10 missed heartbeats. This setting corresponds to 12 seconds. How to Configure the Cluster Networks for a Single Copy Cluster.
3. Quorum is set with Node Majority with Disk Witness. This is described in setting up Cluster with SCC. How to Configure the Node and Disk Majority Quorum.
4. Installing on Windows 2008 How to Install the Active Clustered Mailbox Role in a Single Copy Cluster on Windows Server 2008.
5. One issue with solution is on creating new mailboxes on second mailbox server with proxy generator DLL issues:
In an SCC that contains multiple clustered mailbox servers, there is a known issue where you might not be able to create new mailboxes on the second and any subsequent clustered mailbox server that was installed in the failover cluster. When this issue occurs, attempts to create a new mailbox on the second or subsequent clustered mailbox server in the cluster will fail with the following error message: "A proxy generator DLL on server FQDN.serverName could not be found or failed to initialize. Proxy addresses for the current recipient cannot be calculated. Please ensure that all proxy address generator DLLs have been installed on the target server." You can resolve this issue by creating the new mailbox on another Mailbox server, and then moving that mailbox to the second or subsequent clustered mailbox server in the cluster. You can also resolve this issue by creating a Microsoft MTA object in Active Directory for the clustered mailbox server. For detailed steps, see How to Enable Mailbox Creation on the Second or Successive Clustered Mailbox Server of an Exchange 2007 Single Copy Cluster.
Installing SCC on Windows 2008 - http://technet.microsoft.com/en-us/library/bb629581(EXCHG.80).aspx
This article is for CCR, I'll admit, but they say 300 seconds (5 minutes). Not 10 minutes. Is CCR different in this way? I would think it isn't.
Could you elaborate on why you are recommending a Witness disk quorum in a geographic cluster? I would think that you would recommend an MNS w/FSW or just plain MNS over a shared disk quorum in a geo-cluster.