[ovirt-users] Ovirt VM Performance abd CPU times

[Xavier Naveira]

Hi,

We have installed and added a new hypervisor into the ovirt cluster but
this time with disabled HT.

I migrated a RedHat 5.10 machine to it and immediately the qemu-kvm process
running the vm (freshly installed, just basic packages) began to consume
20-40% CPU as showed running top on the hypervisor.

Now that I have a hypervisor to run tests in, what would you suggest the
next step is?

Thank you.

Xavier

On Thu, Oct 30, 2014 at 12:38 PM, Xavier Naveira <xnaveira at gmail.com> wrote:

> Yeah, that's definitively worth a try. The problem is that we have been
> running on ovirt for some months now and haven't realized the problem with
> the RHEL 5.x vms until recently, when we began to import them (until now we
> mainly run RHEL 6.x vms), so the ovirt hypervisors are production machines
> and I don't have a lot of margin doing tests on them. Hopefully next week
> we'll be able to decomission another of the "old ones" and then we can do
> some testing before adding it to the ovirt cluster... The other thing that
> we're going to test is disabling HT.
>
> X
>
> On Thu, Oct 30, 2014 at 12:33 PM, Gianluca Cecchi <
> gianluca.cecchi at gmail.com> wrote:
>
>> On Thu, Oct 30, 2014 at 12:25 PM, Xavier Naveira <xnaveira at gmail.com>
>> wrote:
>>
>>> These hardware is exactly the same, no changes in bios, reinstalled from
>>> scratch.
>>>
>>> The versions in the "old ones" are:
>>>
>>> RHEL 5.6
>>> kvm-83-224.el5
>>> libvirt-0.8.2-15.el5_6.1
>>> kmod-kvm-83-224.el5
>>> kvm-tools-83-224.el5
>>> libvirt-0.8.2-15.el5_6.1
>>> Kernel: 2.6.18-238.1.1.el5 #1 SMP Tue Jan 4 13:32:19 EST 2011 x86_64
>>> x86_64 x86_64 GNU/Linux
>>>
>>> I the ovirt "new" ones:
>>>
>>> RHEL 6.5
>>> qemu-img-rhev-0.12.1.2-2.415.el6_5.14.x86_64
>>> qemu-kvm-rhev-0.12.1.2-2.415.el6_5.14.x86_64
>>> qemu-kvm-rhev-tools-0.12.1.2-2.415.el6_5.14.x86_64
>>> libvirt-0.10.2-29.el6_5.12.x86_64
>>> libvirt-client-0.10.2-29.el6_5.12.x86_64
>>> Kernel: 2.6.32-431.23.3.el6.x86_64 #1 SMP Wed Jul 16 06:12:23 EDT 2014
>>> x86_64 x86_64 x86_64 GNU/Linux
>>>
>>> I haven't gone into the details but the command line generated by our
>>> old software is like 2 lines of text while in the ovirt nodes for the same
>>> type of machine it is 10 :)
>>>
>>>
>>>
>>
>> So one "important" thing is that hypervisor OS was RHEL 5 with plain
>> Qemu/KVM and instead RHEL 6 with oVirt....
>> You could check if plain Qemu/KVM with RH EL 6.5 generates the same
>> problems for RHEL 5.x VMs..
>> Not that it would solve the problem itself, but it would help to put the
>> different OS version of hypervisor as a possible cause
>>
>>
>
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