On 2017-05-29 11:05, Sylvain Leroux wrote: > > On 05/29/2017 08:41 AM, Jan Kiszka wrote: >> It's more productive to develop hypervisors than to write about them. ;) > > _I_ agree with that. My boss, not necessary. > > > To let you know at which point non-IT people may be stuck, in a > different area I'm still required to teach "classfull" IP networking. > Seriously, that was obsoleted by RFC1518/1519 more that 20 years ago! > How many of my students will encounter devices still using classfull > network? > >> >> People like classifications. They suggest the world is simple and can be >> abstracted. You need to look closer to understand that this is generally >> not that simple. But that's a boring, often disliked story to tell... > > Yes, exactly. That's why I wanted to take time discussing with you, > "experts" about that topic. It would have been hundred times more easy > to just copy-paste and rehash the same story we can find in a plethora > of blog posts. > > But my boss will _not_ do that. If he sees in my course outline that > "hypervisor type 1 type 2 classification is meaningless", he will type > that in his favorite search engine and will find pages and pages of > results saying the exact opposite. > > > Going back to your initial argument Jan, seconded by Christoph: >> It's more productive to develop hypervisors than to write about them. ;) > > On 05/29/2017 10:13 AM, Christoph Hellwig wrote: >> I never understood why people cared about it too much, the terms come >> from a academic paper in the 70s and we're even fully correct back >> then, and have gotten less an less useful. > > > If we want those arguments to be heard by a large audience, I think we > cannot avoid the need for some "authority" to publish about that. Call > that a manifesto or a paper, but the point is people like me would have > an "argument from authority" to quote and reference, so that will become > an idea to discuss, rather than just an opinion exchanged by some people > in a mailing lists. See, the classification attempt is an academic approach to an academic problem. Most folks here are engineers. Their business is to find architectures that create optimal combinations of what is technically possible. That's what you may make them write or talk about. But you may soon cite another example for how meaningless the classification is in practice: "[...] This scheme does not fit into the traditional classification of hypervisors [7] – it can be seen as a mixture of Type-1 and Type-2 hypervisors: It runs on raw hardware like a bare-metal hypervisor without an underlying system level, but still cannot operate without Linux as a system aide to provide initialised hardware. Linux is used as bootloader, but not for operation." >From the accepted OSPERT17 paper of a student of us on the Jailhouse hypervisor architecture. Maybe I could motivate him writing about the classification nonsense alone as well, but he is also very good engineer and code contributor... ;) And if you want to do something good to your students: teach concepts by practical examples, particularly the exceptions from textbook rules. Jan
