Hi folks, I posed these questions on debian-devel and was told I should be asking them here. Also, I got some rather contradictory information on -devel so perhaps this is a good idea. I'll repeat my questions along with the answers I saw on -devel, and perhaps some light can be shed on it here. I will happily summarize on -devel.
According to http://wiki.debian.org/SystemVirtualization : "Qemu and KVM - Mostly used on Desktops/Laptops" "VirtualBox - Mostly used on Desktops/Laptops" "Xen - Provides para-virtualization and full-virtualization. Mostly used on servers. Will be abandoned after squeeze." + Andrew M. A. Cater: Xen doesn't keep anywhere current in terms of kernel - if we release Squeeze this year with kernel 2.6.3*, Debian will have to maintain all the patches/ "forward port" them to 2.6.32 or 2.6.33 as was done with 2.6.2*. + Goswin von Brederlow: I think we can all agree that the old style xen patches from 2.6.18 and forward ported to newer kernels in lenny are unmaintainable. But the pv-ops xen kernel is shaping up well and that is what Bastian Banks is working on. They have a proper upstream and follow the latest vanilla kernel well enough. According to the wiki the plan is to have pv-ops merge into vanilla with 2.6.34. + Olivier Bonvalet: Linux dom0 kernel from Lenny doesn't work at all on some hardware with recent pv_ops domu. In that case you have to change to a different version... The Xen page on the wiki makes no mention of this. So, I am wondering about our direction in this way: *** 1) Will a squeeze system be able to run the Xen hypervisor? A Xen dom0? + Ben Hutchings: Maybe. Ian Campbell and Bastian Blank are working on it. + Bastian Blank: [re hypervisor] Why not? I see packages laying around. [re dom0] Most likely yes. I'm currently ironing out the obvious bugs. *** 2) Will a squeeze system be able to be installed as a Xen domU with a lenny dom0? What about squeeze+1? + Ben Hutchings: lenny's xen-flavour kernels (needed for dom0, optional for domU) are not supportable even now. + Bastian Blank: Yes. It should even run on RHEL 5. + Olivier Bonvalet: I have a Debian squeeze running on a Lenny Dom0 Xen. Today it seem to works. *** 3) What will be our preferred Linux server virtualization option after squeeze? Are we confident enough in the stability and performance of KVM to call it such? (Last I checked, its paravirt support was of rather iffy stability and performance, but I could be off.) + Marco d'Itri: [regarding KVM stability]: Yes. [regarding my impressions of KVM being wrong]: You are, KVM had huge changes in the last year. + Andrew M.A. Cater: KVM is shaping up well and appears to be very well supported by Red Hat. + Goswin von Brederlow: But still slower and less secure due to qemu. *** 3a) What about Linux virtualization on servers that lack hardware virtualization support, which Xen supports but KVM doesn't? Marco d'Itri: Tough luck. *** 4) What will be our preferred server virtualization option for non-Linux guests after squeeze? Still KVM? + Marco d'Itri: Yes, virtualized Windows works much better in (modern) KVM than Xen. *** 5) Do we recommend that new installations of lenny or of squeeze avoid Xen for ease of upgrading to squeeze+1? If so, what should they use? + Ben Hutchings: I would discourage use of the xen-flavour in lenny. + Marco d'Itri: It depends. KVM in lenny is buggy and lacks important features. While it works fine for development and casual use I do not recommend using it in production for critical tasks. This is where Red Hat really beats us: RHEL shipped Xen years ago but recently they released an update which provides a backported and stabilized KVM. + Andrew M. A. Cater: New Squeeze - use KVM? New Lenny - whatever you want, because at this point you have (days until release of Squeeze + 1 year) to find an alternative. *** 6) Are we communicating this to Debian users in some way? What can I do to help with this point? + Marco d'Itri: Remind people that Xen is dying and KVM is the present and the future. + Samuel Thibault: [to Marco] No FUD, thanks. Thanks, -- John -- To UNSUBSCRIBE, email to debian-kernel-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4b87d8a3.10...@complete.org
