Re: [ovirt-users] Ovirt VM Performance abd CPU times

On 10/29/2014 01:26 PM, Daniel Helgenberger wrote: > On 29.10.2014 11:48, Xavier Naveira wrote: >> On 10/29/2014 11:47 AM, Xavier Naveira wrote: >>> On 10/29/2014 11:40 AM, Daniel Helgenberger wrote: >>>> >>>> >>>> On 29.10.2014 10:21, Xavier Naveira wrote: >>>>> Hi, >>>>> >>>>> We are migrating our ifrastructure from kvm+libvirt hypervisors to >>>>> ovirt. >>>>> >>>>> Everything is working fine but we're noticing that all the qemu-kvm >>>>> processes in the hypervisors take a lot of CPU. >>>> Without further details of the workload this is hard tell. One >>>> Reason I >>>> can think of might be KSM [1]. Is it enabled on your cluster(s)? >>>> What is >>>> your mem over-commitment setting? >>>> >>>> Note, IIRC the KSM policy is currently hard coded; it will start at >>>> 80% >>>> host mem usage. >>>> >>>> [1] http://www.ovirt.org/Sla/host-mom-policy >>>>> >>>>> The typical example is an idle machine, running top from the machine >>>>> itself it reports cpu use percentages below 10% and loads (with 2 >>>>> processors) of 0.0x. The process running that machine in the >>>>> hypervisor >>>>> rports cpu uses in the order of the 80-100%. >>>>> >>>>> Should the values look like this? Why are the idle machines eating >>>>> up so >>>>> much CPU time? >>>>> >>>>> Thank you. >>>>> Xavier >>>>> >>>>> _______________________________________________ >>>>> Users mailing list >>>>> Users(a)ovirt.org >>>>> http://lists.ovirt.org/mailman/listinfo/users >>>>> >>>> >>> >> Hi, thank you for the answer. >> >> I've been trying to work out some pattern and realized that the VMs >> using that much cpu all are Redhat 5.x, the Readhat 6.x doesn't exhibit >> this kind of high cpu use. (we run only redhat/centos 5.x/6.x on the >> cluster) > What OS are the hosts running? In case of EL6, make sure you have > tuned-0.2.19-13.el6.noarch installed [1]. That's exactly the version we've in the hypervisors.

> > To further investigate please post Engine, VDSM, libvirt and kernel > versions from the hosts. vdsm-xmlrpc-4.14.11.2-0.el6.noarch vdsm-cli-4.14.11.2-0.el6.noarch vdsm-python-4.14.11.2-0.el6.x86_64 vdsm-4.14.11.2-0.el6.x86_64 vdsm-python-zombiereaper-4.14.11.2-0.el6.noarch libvirt-client-0.10.2-29.el6_5.12.x86_64 libvirt-0.10.2-29.el6_5.12.x86_64 libvirt-lock-sanlock-0.10.2-29.el6_5.12.x86_64 libvirt-python-0.10.2-29.el6_5.12.x86_64 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 > > [1] https://access.redhat.com/solutions/358033 >> >> I'll take a look to the KSM config. >> >> Cheers, >> >> Xavier >> >