In most of the VMware vSphere Environments (and even more with vSAN) the firmware and driver management is a critical and at the same level annoying task.
One of the biggest challenges in managing an enterprise platform is the Capacity Planning Strategies.
Last few months I was involved in a rollout project of a large application on VMware vSphere. During the phases of the rollout, we had few tricky performance issues to solve, but one of them was pretty special.
Last few weeks I had a lot of discussions on how to make a VMware Private Cloud Environment accountable or measurable.