Will this work: Adding a clustered SQL Server 2K8 R2 instance to an existing Windows Server 2008 Cluster with multiple SQL Server 2005 SP4 instances?

Hello all,

We have recently begun to run into situations where some applications are requiring SQL server 2008 r2. Because of that, we were wanting to see if it were possible to add a clustered SQL Server 2008 R2 instance to our existing SQL 2005 SP4 cluster running Windows Server 2008. We would like to run both versions concurrently in the cluster, in separate instances obviously, if at all possible.

I believe I've seen where it was supported with SQL server 2008, but was wanting to confirm whether or not that was still the case with SQL Server 2008 R2. I'm also curious if there are any "gotchas" that others have come across doing something like this.

Thanks