Virtualization Wtf

For reasons that don’t need exploring at this juncture, I decided to start reading through a bunch of papers on virtualization, and I thought I’d force myself to actually do it by publicly committing to blogging about them.

First on deck is Disco: Running Commodity Operating Systems on Scalable Multiprocessors, a paper from 1997 that itself “brings back an idea popular in the 1970s” – run a small virtualization layer between hardware and multiple virtual machines (referred to in the paper as a virtual machine monitor; “hypervisor” in more modern parlance). Disco was aimed at allowing software to take advantage of new hardware innovations without requiring huge changes in the operating system. I can speculate on a few reasons this paper’s first in the list:

• if you have a systems background, most of it is intelligible with some brow-furrowing
• it goes into a useful level of detail on the actual work of intercepting, rewriting, and optimizing host operating systems’ access to hardware resources
• the authors went on to found VMware, a massively successful virtualization company

I read the paper intending to summarize it for this blog, but I got completely distracted by the paper’s motivation, which I found both interesting and unexpected.