<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Wed, May 18, 2016 at 8:01 PM, Karli Sjöberg <span dir="ltr"><<a href="mailto:karli.sjoberg@slu.se" target="_blank">karli.sjoberg@slu.se</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div><br></div><div><span><p dir="ltr">
>> > I tried a vanilla centos-7.1 as well and the same happens. I'm of the same opinion that this is more a guest related issue, it's just I'd like to find out why this only happens with QXL and not with CIRRUS.<br>
>> ><br>
>> > Thanks.<br>
>><br>
>> Very interesting. Are your hosts all of the same architecture(family)?<br>
>><br>
>> /K<br>
><br>
><br>
> Actually we have a nice mixture of manufacturers. We run 7 hosts, paired 4-2-1 in relation to architecture. All of them have the same resources, though (CPUs + RAM). In this case, I can't test the VM on different hosts because we've separated one of them
(one of the "4") on a standalone oVirt datacenter as we're making tests on it, but I remember this has already happened to me in the past (I didn't have the time to debug it at that time, though).</p>
</span><p dir="ltr">And it doesn't happen with a similar VM in the other datacenter, on the same hardware?</p><span><font color="#888888">
<p dir="ltr">/K</p></font></span></div></blockquote><div><br></div><div>Hello,<br></div><div>I would like to come back to the original post to get some clarifications:<br></div><div>you write<br>"<br></div></div> I've deployed a pretty basic VM (ubuntu 14.04 server, 4GB RAM, 4 CPUs, 15GB storage).<br>"<br></div><div class="gmail_extra">It seems to me not so basic a VM with 4 vcpus for a desktop.... what are your needs for it? <br></div><div class="gmail_extra">In general a multi cpu VM could have a worse performance than a mono cpu one, depending on its actual workload, because from the host side there is a continuous scheduling of these 4 vcpus among the real cpus/cores/threads.<br></div><div class="gmail_extra">I worked in the past with a 4 vcpu VM and 24Gb of ram (in vSphere) used as JDEdwards database server with hundreds of concurrent users ...<br></div><div class="gmail_extra">Also with JBoss VMs configured with 4-6 vcpus .. But for a basic VM seems somehow overestimated... <br></div><div class="gmail_extra">In my case on a nuc6i5 with 2 cores + ht and 32Gb of ram, configured as hypervisor with self hosted engine VM, I have a CentOS 6 VM configured with 3Gb of ram and 1 cpu and it runs quite smooth from inside a spice session configured with resolution of 1680x1050 and its cpu usage shows 98.5% idle.<br></div><div class="gmail_extra">Also from the host point of view<br><br> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND <br>16025 qemu 20 0 8988404 3.070g 10524 S 1.7 9.9 90:16.07 qemu-kvm <--- engine VM <br>24367 qemu 20 0 3852288 1.929g 12188 S 0.0 6.2 41:12.79 qemu-kvm <---- CentOS 6 VM<br><br></div><div class="gmail_extra">If I add to the mix a CentOS 7.2 VM configured with 1 vcpu and 3Gb of ram and with a classic gnome desktop session and open it with 1680x1050 resolution too in spice, I can work without problems and with great fluidity. I see inside vm its cpu jumping from 1% to 6% because of gnome-shell. <br><br></div><div class="gmail_extra">I see this at host side while in CentOS 7 VM the packagekitd daemon is downloading the updates and so it is comsuming cpu cycles, also due to virtual network activity<br></div><div class="gmail_extra"> <br> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND <br>16025 qemu 20 0 9004796 3.077g 10524 S 2.0 9.9 90:27.34 qemu-kvm <br>24367 qemu 20 0 3852288 1.929g 12188 S 0.7 6.2 41:17.35 qemu-kvm <br>31277 qemu 20 0 4121224 2.116g 12056 S 16.3 6.8 2:13.80 qemu-kvm <br><br></div><div class="gmail_extra">Otherwise very few cpu usage, after packagekitd completes its work;<br><br> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND <br>16025 qemu 20 0 9004796 3.077g 10524 S 2.3 9.9 90:34.42 qemu-kvm <br>24367 qemu 20 0 3852288 1.929g 12188 S 0.7 6.2 41:20.42 qemu-kvm <br>31277 qemu 20 0 3834364 2.138g 12056 S 1.0 6.9 2:28.80 qemu-kvm <br><br>HIH debugging,<br></div><div class="gmail_extra">Gianluca<br><br></div></div>