Microsoft not supporting VMware vCenter on MSCS Clusters
Duncan Epping at Yellow Bricks calls attention to a MSFT KB article which clearly states that Microsoft does NOT support clustering vCenter with Microsoft Cluster Server (MSCS).
High Availability for vCenter is critical for your virtual infrastructure. If your vCenter server is unavailable, not only have you lost a central management point, but you have lost all DRS and HA capability as well. In other words you’re working without a net for your VMs and you lost your primary management tool. Many other functions like backups will also depend on the availability of vCenter.
vCenter Server Heartbeat is an excellent solution for this problem. vCenter Server Heartbeat is based on the Neverfail’s High Availability solution which is replication-based as opposed to a shared-storage model like MSCS. I had the opportunity to work with one of Neverfail’s engineers shortly before he went to VMWare to focus on the vCenter Heartbeat solution and when properly configured it is a very strong HA solution for vCenter.
64-bit support was added last year (5.5 Update 2) so you can now use it to protect a vCenter that is on Windows 2008 x64 (2008 R2 is not yet supported).
vCenter Heartbeat also has some nice features like automatically creating the standby-server using the clone function if vCenter is already running as a VM.
If you are running mission critical servers in your virtual infrastructure you should take a look at vHeartbeat to provide high availability for the HA and DRS functions.
UPDATE: vCenter Server Heartbeat 6.3 has been released. It supports vSphere 4.1, Windows 2008 R2 and more. More details are in the Release Notes for 6.3.