[Openstack-operators] User Survey usage of QEMU (as opposed to KVM) ?

Robert Starmer robert at kumul.us
Wed May 11 19:29:38 UTC 2016


I don't disagree, what we're really getting at is that any lookup (ask the
system what it's using on a particular instance, look at the config, look
at the output of a nova CLI request, querry via Horizon), should all return
the same answer.  So one is a bug (Horizon), the other requires looking up
information in the system itself.  As I suggested, the config is one path,
and I still believe will provide the current correct answer for the
hypervisor node (Linux QEMU/KVM or QEMU/QEMU) regardless of other issues,
and the Horizon path is a bug that should be fixed.

R

On Wed, May 11, 2016 at 9:20 AM, Maish Saidel-Keesing <maishsk at maishsk.com>
wrote:

> Or we could just fix the problem within OpenStack to report the correct
> Hypervisor in the first place.
>
> This kind of reminds me of a story.
>
> Someone was trying to drive down a path on his bicycle, but there were
> some tacks on the path.
> So his wheel kept on getting full of holes. So they thought and thought of
> how to overcome the problem.
>
> They built small jet engines into the bike so that they could hover over
> the ground, instead of riding over
> the tacks.
>
> They were happy because they could now go down the path.
>
> The simple answer should have been - get off the bike and pick up the
> tacks - instead of finding ways to
> over-engineer the problem
>
> Either show the right thing - or don't show it at all.
>
> My 0.02 Shekels.
> On 11/05/16 22:06, Robert Starmer wrote:
>
> You could just ask for the value of virt_type parameter from a compute
> host (or the output of something like grep 'virt_type' /etc/nova/nova*) if
> you are using qemu or kvm.  I believe that's how nova figures out what
> parameters to use when launching an instance.
>
> On Wed, May 11, 2016 at 8:39 AM, Kris G. Lindgren <klindgren at godaddy.com>
> wrote:
>
>> In the next user survey - could we clarify that qemu == full software cpu
>> emulation and kvm (qemu/kvm) = hardware accelerated virtualization or some
>> similar phrasing.  It's totally possible that people are like: I run both
>> qemu and kvm (thinking that’s qemu/kvm) - when in fact they only run kvm
>> (qemu/kvm).
>>
>> ___________________________________________________________________
>> Kris Lindgren
>> Senior Linux Systems Engineer
>> GoDaddy
>>
>>
>>
>>
>>
>>
>>
>> On 5/11/16, 11:58 AM, "Tim Bell" < <Tim.Bell at cern.ch>Tim.Bell at cern.ch>
>> wrote:
>>
>> >Does anyone see a good way to fix this to report KVM or QEMU/KVM ?
>> >
>> >I guess the worry is whether this would count as a bug fix or an
>> incompatible change.
>> >
>> >Tim
>> >
>> >On 11/05/16 17:51, "Kashyap Chamarthy" < <kchamart at redhat.com>
>> kchamart at redhat.com> wrote:
>> >
>> >>On Tue, May 03, 2016 at 02:27:00PM -0500, Sergio Cuellar Valdes wrote:
>> >>
>> >>[...]
>> >>
>> >>> I'm confused too about the use of KVM or QEMU In the computes the
>> >>> file​/etc/nova/nova-compute.conf has:
>> >>>
>> >>> virt_type=kvm
>> >>>
>> >>> The output of:
>> >>>
>> >>> nova hypervisor-show <id> | grep hypervisor_type
>> >>>
>> >>> is:
>> >>>
>> >>> hypervisor_type           | QEMU
>> >>
>> >>As Dan noted in his response, it's because it is reporting the libvirt
>> driver
>> >>name (which is reported as QEMU).
>> >>
>> >>Refer below if you want to double-confirm if your instances are using
>> KVM.
>> >>
>> >>>
>> >>> The virsh dumpxml of the instances shows:
>> >>>
>> >>> <domain type='kvm' id='44'>
>> >>
>> >>That means, yes, you using KVM.  You can confirm that by checking your
>> QEMU
>> >>command-line of the Nova instance, you'll see something like
>> "accel=kvm":
>> >>
>> >>      # This is on Fedora 23 system
>> >>      $ ps -ef | grep -i qemu-system-x86_64
>> >>      [...] /usr/bin/qemu-system-x86_64 -machine accel=kvm [...]
>> >>
>> >>> ....
>> >>> <emulator>/usr/bin/qemu-system-x86_64</emulator>
>> >>>
>> >>> ​But according to ​this document [1], it is using QEMU emulator
>> instead of
>> >>> KVM, because it is not using /usr/bin/qemu-kvm
>> >>>
>> >>>
>> >>> So I really don't know if it's using KVM or QEMU.
>> >>
>> >>As noted above, a sure-fire way to know is to see if the instance's QEMU
>> >>command-line has "accel=kvm".
>> >>
>> >>A related useful tool is `virt-host-validate` (which is part of
>> libvirt-client
>> >>package, at least on Fedora-based systems):
>> >>
>> >>   $ virt-host-validate | egrep -i 'kvm'
>> >>    QEMU: Checking if device /dev/kvm exists
>>        : PASS
>> >>    QEMU: Checking if device /dev/kvm is accessible
>>         : PASS
>> >>
>> >>
>> >>> [1] https://libvirt.org/drvqemu.html
>> >>>
>> >>
>> >>
>> >>--
>> >>/kashyap
>> >>
>> >>_______________________________________________
>> >>OpenStack-operators mailing list
>> >>OpenStack-operators at lists.openstack.org
>> >>http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>> >
>> >_______________________________________________
>> >OpenStack-operators mailing list
>> >OpenStack-operators at lists.openstack.org
>> >http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>> _______________________________________________
>> OpenStack-operators mailing list
>> OpenStack-operators at lists.openstack.org
>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>>
>
>
>
> _______________________________________________
> OpenStack-operators mailing listOpenStack-operators at lists.openstack.orghttp://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-operators
>
>
> --
> Best Regards,
> Maish Saidel-Keesing
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack-operators/attachments/20160511/ca279985/attachment-0001.html>


More information about the OpenStack-operators mailing list