I recently wrote here about my experiences testing out the new Windows Server 2012 feature, cluster aware updating with SQL Server AlwaysOn Availability Groups. As you see in the post, it didn’t go so well. I didn’t have the opportunity to test on the more traditional SQL Server Failover Cluster instance.
Well after the Thanksgiving holiday, I was able to get my infrastructure up and running and build a Failover Cluster Instance. Note—I was using SQL 2012 SP1 and Windows 2012, and use Starwind SAN software for the shared storage requirement. I am very happy to report, that the Cluster Aware Updating process simply worked, and failed over the instance correctly. So in order to configure this, you will simply need to configure Cluster Aware Updating and not do anything else to SQL Server. Details on Cluster Aware Updating can be found here.
I suspect the issue with AlwaysOn Availability Groups relates to the way it interacts with the cluster service. In our traditional model of failover clusters, do all of our instance control through Failover Cluster Manager, however with AlwaysOn AGs we are specifically instructed not to:
So I think since Cluster Aware Updating is attempting to manipulate that service, that is what is causing the errors. Just my thoughts, please share yours!
I have been reading your blog for a long time and really appreciate your writings.
I do not know if you have already seen this, but there is a whitepaper on CAU. In the whitepaper, you will find that “Microsoft does not support the use of CAU to update Windows Server 2012 clusters with SQL Server AlwaysOn availability groups. CAU is currently not aware of AlwaysOn availability groups”
Thanks I’ve been meaning to update this with that whitepaper. I have had some discussions with the MS product team and they are planning to support it in a later version.