A: I subscribe to the same guidance I have given in the past around high availability solutions in the application or in the hypervisor. If the application has its own fault-tolerant capability, such as Exchange DAG, or SQL Server Mirroring, then use the application's capabilities.
If there is no application fault-tolerant solution, and you need zero down-time unplanned protection, then look at hypervisor-level fault tolerance. However, some solutions might impose requirements and restricts that aren't practical for the desired workload to be protected.
To see more FAQs, please go to John Savill's FAQs page on Windows IT Pro.