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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue;mso-fareast-language:EN-US">Hi all,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue;mso-fareast-language:EN-US">I think I found the solution on yesterday. The host which causes the CPU problems is in a cluster
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue;mso-fareast-language:EN-US">where the KSM option is activate. Someone here must have check it.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue;mso-fareast-language:EN-US">I disable KSM on the cluster, disable NUMA and CPU pass through in the vm parameters, and no more high CPU usage by migration thread. Hope
this solution can help someone else !<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:blue;mso-fareast-language:EN-US">Styve<o:p></o:p></span></p>
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</span><span style="font-size:7.5pt;font-family:"Verdana",sans-serif;color:blue">Réponse ou transfert de la part de
<b>Styve JAUMOTTE</b></span><span style="mso-fareast-language:EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">De :</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Doron Fediuck [mailto:dfediuck@redhat.com]
<br>
<b>Envoyé :</b> dimanche 25 septembre 2016 08:27<br>
<b>À :</b> jaumotte, styve<br>
<b>Cc :</b> users@ovirt.org; Martin Sivák<br>
<b>Objet :</b> Re: [ovirt-users] High CPU Usage caused by migration thread on Node<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Wed, Sep 21, 2016 at 12:28 PM, jaumotte, styve <<a href="mailto:s.jaumotte@maine-et-loire.fr" target="_blank">s.jaumotte@maine-et-loire.fr</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Hi,</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">We’ve got a problem with a critical machine which running Oracle Database and if someone can help us it
would be very nice.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Our VM is running rhel 6.5 and is configuring with 16 cores (2 virtual socket with 8 virtual cores) and
240Gb. </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">This virtual machine is running perfectly on the first host R620 : two cpu E5-2695 v2 - 12 cores on each
cpu - and 384Gb of memory.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">We wan’t to move this virtual machine on a new server, Transtec with two E5-2650 v3 – 10 cores on each
cpu – and 256Gb of memory. We have encountered high cpu usage on this host.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Both servers are running centOS 7.2 and ovirt 3.6. We have already identified that on the node, many « migrate/N »
are causing high cpu usage.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">We have tried few options :
</span><o:p></o:p></p>
<p><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">-</span><span style="font-size:7.0pt;color:black">
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Pass-Through Host CPU</span><o:p></o:p></p>
<p><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">-</span><span style="font-size:7.0pt;color:black">
</span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Configure NUMA : numa node count = 2, numa pinning
</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">The first day the machine was running, everything is ok and migrate threads disapeared, but on the second
day, high cpu and migration thread were back. Oracle services are being restarted everyday for cold backup but not the virtual machines.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">I don’t know if looking in the Numa options is a good idea and I don’t why the everything is running ok
on the R620 (perhaps the available memory)</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Thank you for your advices.</span><o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><span style="color:#888888"><o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Styve</span><span style="color:#888888"><o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><span style="color:#888888"><o:p></o:p></span></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black"> </span><span style="color:#888888"><o:p></o:p></span></p>
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<p class="MsoNormal">Hi Styve,<o:p></o:p></p>
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<p class="MsoNormal">Pass-Through Host CPU is irrelevant unless you have a specific CPU flag you need to utilize.<o:p></o:p></p>
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<p class="MsoNormal">So I suggest you refrain from using it.<o:p></o:p></p>
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<p class="MsoNormal">As for NUMA, it works well as long as it's not interleaving. Here as well you should use it only<o:p></o:p></p>
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<p class="MsoNormal">if you understand how it should be used. Otherwise the safe option for you is vCPU pinning.<o:p></o:p></p>
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<p class="MsoNormal">Can you please check your logs to see who is creating these threads and share it?<o:p></o:p></p>
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