It&#x27;s not the same as using something like DTrace on a live system, but he&#x27;s describing it as though eliminating the flexibility implies some sort of event horizon.<p>This also bothered me...<p><pre><code>    virtualizing at the hardware layer carries with it an inexorable performance tax
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Hardware has been adding a lot of virtualization support over the last decade, and it&#x27;s generally been a net performance gain as far as I&#x27;m aware.  I could see things like IO scheduling potentially being an issue.  Although, IO performance on top of operating systems in general does not particularly inspire confidence.