I found the article very interesting. As the sole DBA I am currently supporting 2 clustered environments in 2 domains. The headache I am going to be facing next summer is the replacement of the 2 servers in one of the clusters. When we replace hardware, we also upgrade OS. We do not upgrade the OS on existing hardware. The reasons for this can be the subject of another post. This particular cluster is running Windows server 2008 R2 Enterprise. When we replace the hardware these servers will move up to Windows Server 2012 R2. Can Win 2008R2 and Win 2012R2 be clustered together?