What is the best approach to migrate a large database running on Windows 2008R2 and SQL Server 2012 to new hardware running Windows Server 2012R2 and SQL Server 2014?
I was hoping that I could add the new servers to the Windows Server Fail-over Cluster (WSFC), even though they are not the same OS version. If that is possible, then add the Availability Group from the old cluster to the new cluster and add a Availability Replicas for the database and start failing over to the new hardware. Once there remove the old servers from the AG and then from the WSFC.
AlwaysOn 2014 is working on the new machines.
The new servers were configured in their own WSFC, and added to the old Availability Group. This resulted in the database synchronizing to the new server, but never able to come online. I am assuming the reason is that there is no heartbeat between the old and new servers as they are in different WSFC's.
Any best practice advice or guidance is appreciated.