Now that Exchange Server 2010 has had its first birthday, it's a good time to remind folks about the built-in features for high availability, site resilience and disaster recovery in Exchange 201...
Published Dec 16, 2010
Version 1.0
Blog Post
Hi Survey
Correct me if I am wrong, but you are considering the databases as parts of the server environment in your DAGs ? You need to consider the mailboxdatabases as your failover units, NOT the servers. When you consider it like that, it does not really matter where the "live" copy is, what matters is how many copies you have. Scott is right that you will need to set up a CAS array for true HA, and ensure you repoint your mailboxdatabases to the CAS array instead of (as now) the individual CAS server. If you make the boxes you use host both CAS and HT roles, the HT load balancing and failover will take care of itself. Remember also to create a DNS record which points to your CAS array. Lastly, take not of the earlier comments about PF database faiover (if using PFs). You will need to create replicas on alternative Public Folder databases. If you then suffer any of the condition mentioned earlier, failover should be automatic, but if you simply make the primary PF database unavailable (e.g. dismount it), you will need to manually change over the PF database configured for each mailbox database. HTH
Correct me if I am wrong, but you are considering the databases as parts of the server environment in your DAGs ? You need to consider the mailboxdatabases as your failover units, NOT the servers. When you consider it like that, it does not really matter where the "live" copy is, what matters is how many copies you have. Scott is right that you will need to set up a CAS array for true HA, and ensure you repoint your mailboxdatabases to the CAS array instead of (as now) the individual CAS server. If you make the boxes you use host both CAS and HT roles, the HT load balancing and failover will take care of itself. Remember also to create a DNS record which points to your CAS array. Lastly, take not of the earlier comments about PF database faiover (if using PFs). You will need to create replicas on alternative Public Folder databases. If you then suffer any of the condition mentioned earlier, failover should be automatic, but if you simply make the primary PF database unavailable (e.g. dismount it), you will need to manually change over the PF database configured for each mailbox database. HTH