We are running a 2 node sql 2012 cluster (active/active) on windows 2012. We would like to upgrade the operating system from 2012 to 2012 R2. Whats the best way of doing the OS upgrade on the sql cluster?
In order to upgrade the operating system, you need to remove clustering, then do the upgrades, then rebuild the cluster. There's no way to do in-place operating system upgrades on a Windows Server Failover Cluster.