3 ms·

Xen is a classic example of a technology and company that never reached its full market potential due to nerd pride. In this particular case, Redhat/Linus/kern

Xen is a classic example of a technology and company that never reached its full market potential due to nerd pride. In this particular case, Redhat/Linus/kernel hacker's obstinate refusal to add it to the stock kernel. They exhibited NIH and did KVM (which surprise surprise was owned by Redhat). I'm no virtualization expert, but KVM is doing things totally different than everybody else (no hypervisor), and I'm not 100% sure that KVM's way is better. Xen should be a cautionary tale for startups that opening source is not a silver bullet. The capricious behavior of a coterie can kill you even if that coterie is ostensiby not controlled by any company.

viraptor 16y ago
I'm not sure you're about some things you wrote. "nerd pride"? Really? > In this particular case, Redhat/Linus/kernel hacker's obstinate refusal to add it to the stock kernel. Why obstinate? Xen is not a part of a kernel in some ways. Some capabilities of the system have to be maintained in parallel in both the hypervisor and kernel. And it's not like it was rejected because it was a VM solution - another one was proposed and accepted into mainline (KVM). > They exhibited NIH and did KVM (which surprise surprise was owned by Redhat). LKML has a lot of talk about "why"... it wasn't simply NIH. Regarding "owned by Redhat" - it was included first, then owned by RH: * "The Linux kernel 2.6.20 release (February 2007) was the first to include KVM." (wikipedia) * "In September 2008, Red Hat announced the acquisition of Qumranet, Inc. The acquisition included Qumranet's virtualization solutions, including its KVM (Kernel Virtual Machine) platform" (http://www.redhat.com/promo/qumranet/ http://www.redhat.com/promo/qumranet/) > KVM is doing things totally different than everybody else (no hypervisor), and I'm not 100% sure that KVM's way is better. KVM relies on the idea that if the current kernel already does the work, why duplicate the effort? Apart from minimal, verifiable hypervisors idea not being possible... what are your actual objections? I'm not saying KVM is better / worse here... but let's cut the FUD at least.
- anonymous246 16y ago
  I stand corrected wrt Redhat's ownership of KVM. Thanks for the clarification. I re-read some more web pages in the light of your comments, and I remain unconvinced that nerd pride wasn't at the root of the Linux kernel devs dismissal of Xen. It's happened before (Con Kolivas's patches for instance), so I don't think I'm saying anything radical. IIRC, the hypervisor technology is the standard way to do virtualization since the mainframe days. I haven't heard anything remarkable about KVM to convince me that their hypervisor-less architecture is better.
  - viraptor 16y ago
    Re. stuff like Con Kolivas, etc. I recommend listening to this talk: http://mirrors.dotsrc.org/fosdem/2011/maintracks/kernel-development.xvid.avi http://mirrors.dotsrc.org/fosdem/2011/maintracks/kernel-deve... - it gives some real-live perspective on issues of not-accepted modules.

viraptor 16y ago

I'm not sure you're about some things you wrote. "nerd pride"? Really? > In this particular case, Redhat/Linus/kernel hacker's obstinate refusal to add it to the stock kernel. Why obstinate? Xen is not a part of a kernel in some ways. Some capabilities of the system have to be maintained in parallel in both the hypervisor and kernel. And it's not like it was rejected because it was a VM solution - another one was proposed and accepted into mainline (KVM). > They exhibited NIH and did KVM (which surprise surprise was owned by Redhat). LKML has a lot of talk about "why"... it wasn't simply NIH. Regarding "owned by Redhat" - it was included first, then owned by RH: * "The Linux kernel 2.6.20 release (February 2007) was the first to include KVM." (wikipedia) * "In September 2008, Red Hat announced the acquisition of Qumranet, Inc. The acquisition included Qumranet's virtualization solutions, including its KVM (Kernel Virtual Machine) platform" (http://www.redhat.com/promo/qumranet/ http://www.redhat.com/promo/qumranet/) > KVM is doing things totally different than everybody else (no hypervisor), and I'm not 100% sure that KVM's way is better. KVM relies on the idea that if the current kernel already does the work, why duplicate the effort? Apart from minimal, verifiable hypervisors idea not being possible... what are your actual objections? I'm not saying KVM is better / worse here... but let's cut the FUD at least.

anonymous246 16y ago
I stand corrected wrt Redhat's ownership of KVM. Thanks for the clarification. I re-read some more web pages in the light of your comments, and I remain unconvinced that nerd pride wasn't at the root of the Linux kernel devs dismissal of Xen. It's happened before (Con Kolivas's patches for instance), so I don't think I'm saying anything radical. IIRC, the hypervisor technology is the standard way to do virtualization since the mainframe days. I haven't heard anything remarkable about KVM to convince me that their hypervisor-less architecture is better.
- viraptor 16y ago
  Re. stuff like Con Kolivas, etc. I recommend listening to this talk: http://mirrors.dotsrc.org/fosdem/2011/maintracks/kernel-development.xvid.avi http://mirrors.dotsrc.org/fosdem/2011/maintracks/kernel-deve... - it gives some real-live perspective on issues of not-accepted modules.