In my organisation we have plenty of mission critical servers and currently there is a debate whether for critical servers we should use VMWare vSphere 5 or have a dedicated hardware?
The perception from senior management and the developers, some applications (oracle DB / Glashfish / etc..) might not be compatible with vmware because it does not directly interacts with the hardware layer, instead they OS interfaces with the vmware layer (compatibility wise). There is also a argument that the resources are shared among the vmware hosts (performance wise).
My approach is less sceptic and I'm of the opinion that if you assign the necessary resources, the OS will perform regardless dedicated server or VmWare. I also believe that VmWare is the "virtualization standard" (personal opinion), meaning they're compatibility must be quite extensive.
For the sake of discussion, We can pickup the worst case scenario.. 20 TB Oracle Database 11G with 6,000 IOps. How reliable is it running it with VmWare vs Dedicated hardware (server blades)?