The first stable OpenVZ release [LWN.net]

The first stable OpenVZ release

Posted Dec 5, 2005 20:59 UTC (Mon) by kolyshkin (subscriber, #34342)
Parent article: The first stable OpenVZ release

Let me explain LWN readers why openvz patch is against kernel 2.6.8.

OpenVZ kernel introduces another abstraction layer, which means a lot of modifications here and there all across the kernel code. It is quite a complex thing. One of our major goals is stability for end users; indeed, if you host one system, your kernel should be stable, but if you host hundred of such systems, which is the case for OpenVZ, your kernel should be rock solid.

To improve stability, we do not port OpenVZ kernel stuff to each and every vanilla kernel release, instead improving the version we have. What about mainstream kernel bugfixes? We cherry-pick it from newer kernels? What about recent security fixes? We cherry-pick them. What about support for newer hardware? We do update the drivers in our OpenVZ kernel. So, instead of taking a newer kernel which have both good and (hopefully not too much of, but who knows) bad stuff, we stick to that ancient kernel and backporting that good stuff. Also, porting to a newer mainstream kernels needs some significant time and effort, that we'd better spend improving OpenVZ kernel.

More to say, major Linux distro vendors does the very same thing for their kernel. Look at what is the current kernel for RHEL4? It is 2.6.9. But it is quite far from vanilla 2.6.9 - they do also backport mainstream bug fixes, security fixes and merge in newer drivers (aside from a lot of Red Hat own fixes).

Will it stay what way for OpenVZ kernel? Surely not - at some point we will rebase to some more recent 2.6 kernel - at that time this might be 2.6.20 or something like that, we don't really know now.

Finally, if you feel there is something that OpenVZ kernel is missing but should definitely have, be it a security fix or something else - file a bug, preferably with a patch attached. We are open. :)

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The first stable OpenVZ release

Posted Dec 6, 2005 1:10 UTC (Tue) by kolyshkin (subscriber, #34342) [Link]

> That sounds like a maintainance nightmare.

It is actually not as awfully complex as it looks, and really improves stability.

> Are you planning on submitting OpenVZ for inclusion in the kernel tree? That seems like the only viable long-term solution.

Yes we do, it's quite natural, we plan to merge our code mainstream, and even have this ambitious goal in our roadmap. Sure this will be a long process, done in many small steps...nobody expects it to happen overnight. :)