We have total 6 Nodes and 3 failover cluster (Each with two node).

  • Cluster1.TestAD.com(Node1,Node2) - SQL Failover Instance (SQL1) - 1 TB Shared storage
  • Cluster2.TestAD.com(Node3,Node4) - SQL Failover Instance (SQL2)- 1 TB Shared storage
  • Cluster3.TestAD.com(Node5,Node6) - SQL Failover Instance (SQL3)- 1 TB Shared storage

Now we want to create availability group setup between above three SQL instance.

We plan to create new cluster (cluster4.TestAD.com ) with all six node and create Availability groups with all three instance.

SQL Edition : SQL Server 2012 R2 Enterprise

Is it possible? Any other recommendations ?


One of the requirements for AGs is that all instances are participating nodes in the same WSFC. I believe, based on what youa re telling us, is that the 3 instances are, in fact, in 3 separate clusters.

I don't believe that what you are trying to accomplish is possible.

  • We are trying to use three server in AG. All three server has separate role as per my application. So to achieve high availability, we need backup for all the server. – adkalavadia Aug 28 '16 at 17:19
  • So you have 3 servers, all which already participate in their own AGs and have redundancy. I'm not sure what the end-game is here. The only other option would be to put them all in one cluster. – Kris Gruttemeyer Aug 29 '16 at 13:03

As long as you migrate all 3 instances (6 nodes) to the same WSFC (cluster4.TestAD.com) it's completly possible.
Does your application requires MSDTC? Just be aware that it's not supported on SQL2012 and 2014. See more details here.

  • Yes I am aware. We don't need MSDTC. – adkalavadia Aug 28 '16 at 17:21

Yes that is possible, provided you are setting up a new cluster. For 6 nodes, you would have 6 SQL instances. The 6 SQL instances could be primary/secondary, primary/secondary and primary/secondary, so that you still have a failover instance for each of the 3 SQL instances.

Be aware that you will need double the storage, so 6TB. Each SQL instance needs its own storage.

  • In that case i need 6 node licence...!! I started doing it with my approach on my production. I will keep updates here within next week. – adkalavadia Aug 28 '16 at 17:24
  • @adkalavadia, that's not true if you have software assurance. You would only need to license all 6 if you were reading from the secondary replicas. If they are just failover replicas and you have software assurance, the replicas would not need licenses. – Tara Kizer Aug 29 '16 at 0:01

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