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HCI and Data Locality

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While I rarely apply quantum mechanics in my day to day life studying quantum mechanics taught me an important life lesson; things in the real world sometimes operate in ways counter to our intuitive understanding. Unlike the Mandelbrot set and other fractals which look the same no matter how deeply you examine them many things and ideas in the real world look quite different close up than they do at a distance.

Data locality that is storing the data for each virtual machine on the HCI host that VM runs on, is one of those ideas that is intuitively a good idea but upon deeper consideration creates problems that more than outweigh its advantages.

I wrote a Technology Report, with support from our friends at VMware that explores how locality makes vMotion, and especially DRS, more complicated and how locality is antithetical to modern storage features like metadata clones and data deduplication.

For more details, you can download the report here