On 11/08/2010 08:29 PM, Andrew Cathrow wrote: > > > ----- Original Message ----- >> From: "Dennis Jacobfeuerborn"<dennisml@xxxxxxxxxxxx> >> To: "Andrew Cathrow"<acathrow@xxxxxxxxxx> >> Cc: "Bill Davidsen"<davidsen@xxxxxxx>, xen@xxxxxxxxxxxxxxxxxxxxxxx, virt@xxxxxxxxxxxxxxxxxxxxxxx, "M A Young" >> <m.a.young@xxxxxxxxxxxx> >> Sent: Monday, November 8, 2010 1:59:54 PM >> Subject: Re: [fedora-virt] Dom0 xen support in Fedora 15? >> On 11/08/2010 06:02 PM, Andrew Cathrow wrote: >>> >>> >>> ----- Original Message ----- >>>> From: "Bill Davidsen"<davidsen@xxxxxxx> >>>> To: dlaor@xxxxxxxxxx >>>> Cc: xen@xxxxxxxxxxxxxxxxxxxxxxx, virt@xxxxxxxxxxxxxxxxxxxxxxx, "M A >>>> Young"<m.a.young@xxxxxxxxxxxx> >>>> Sent: Monday, November 8, 2010 11:52:08 AM >>>> Subject: Re: [fedora-virt] Dom0 xen support in Fedora >>>> 15? >>>> Dor Laor wrote: >>>>> On 11/08/2010 04:55 AM, M A Young wrote: >>>>> >>>>>> I am trying to work out whether it is practical to propose Dom0 >>>>>> xen >>>>>> support as a feature for Fedora 15. >>>>>> >>>>>> The kernel situation is that Domain 0 has been accepted upstream >>>>>> for >>>>>> 2.6.37. Assuming a 3 month kernel release cycle, F15 will most >>>>>> likely ship >>>>>> with a 2.6.37.x kernel, with 2.6.38 coming out either after the >>>>>> F15 >>>>>> release or just before but too late to be included. If the plan >>>>>> to >>>>>> get key >>>>>> xen drivers into 2.6.38 succeeds, then F15 may be become usable >>>>>> as >>>>>> a >>>>>> Domain 0 system at some point during its lifetime as the kernel >>>>>> package in >>>>>> a Fedora version typically has one major update. >>>>>> >>>>>> If the kernel team accept backported patches then it might just >>>>>> be >>>>>> possible to ship F15 with usable Domain 0 support but the >>>>>> timescale >>>>>> for >>>>>> that would be very tight. >>>>>> >>>>>> The other thing we would need to consider is what needs to be >>>>>> done >>>>>> to make >>>>>> xen friendly enough to be usable by an ordinary user. The page >>>>>> https://fedoraproject.org/wiki/Features/XenPvopsDom0 contains >>>>>> plans >>>>>> from >>>>>> when dom0 xen support was expected to make a quick return to >>>>>> Fedora, but >>>>>> they are a couple of years old now so probably need updating. >>>>>> >>>>>> I think as a minimum we would need a way to add a dom0 enabled >>>>>> grub >>>>>> entry >>>>>> for a kernel, rather than requiring the user to hand edit the >>>>>> grub >>>>>> file. >>>>>> We should also make sure that xen works with the other Fedora >>>>>> virtualisation tools. >>>>>> >>>>>> What do others think about this? For example is it achievable as >>>>>> a >>>>>> feature, is it too early and better to wait for F16, and what >>>>>> else >>>>>> should >>>>>> we aim to do to make xen usable in Fedora? >>>>>> >>>>> Have you consider kvm? it's upstream since 2.6.20 and now its more >>>>> ready >>>>> than ever. >>>>> >>>> >>>> There are some good tutorials which should explain the difference >>>> between xen and kvm, particularly the performance and hardware >>>> requirements of each. >>> >>> re: hardware requirements, KVM's requirement for VT-X/AMD-V >>> extensions certainly used to be a concern 2-3 years ago but today >>> even laptops come with this support. >>> And regarding performance they days of Xen outperforming KVM have >>> long-since passed. >> >> Citations needed. I'm not saying what you claim isn't true but without >> data >> this opinion doesn't carry much weight. >> > > Citations are really needed on both sides of the debate, 2 or 3 year old metrics no longer apply. Which is why I hoped I could nudge you into providing some data if you had any. :) There seems to be very little recent and hard data on the subject out there. > Vendors published benchmarks are typically questionable, they focus on their products strengths and their competitors weakness. > The only hope for a fair comparison is a vendor neutral set of benchmarks such as SPECvirt http://www.spec.org/virt_sc2010/ > But obviously this isn't a simple test to run. AFAIK there are some issues with that benchmark not being free. What I'm basically looking for is a simple comparison of a few key metrics between common setups. For example a simple bonnie++ run on XenPV and KVM+virtio_blk could already give people at least some baseline numbers. Regards, Dennis -- xen mailing list xen@xxxxxxxxxxxxxxxxxxxxxxx https://admin.fedoraproject.org/mailman/listinfo/xen
