Just what are the important performance factors for Virtualization?

• Throughput: can the application deliver the required levels of throughput, in terms of real world transactions?
• Latency: is the latency of each transaction within tolerances, or affected by virtualization
• Scalability: does throughput/latency change as load is increased (often asked in the context of – “do I have enough future headroom?”)
• Memory efficiency: Doing more work with less memory – multi-core is rapidly providing an increasing amount of CPU, but memory remains a premium
• Power-performance: Throughput relative to power, i.e. how much performance can I deliver for the power consumed
• Space-performance: How much performance can I get per rack unit
• Agility: What is the time taken to deploy a new application