<p dir="ltr">OK,<br>
Thanks for the helpfull information. Learned something more again!</p>
<p dir="ltr">Kind regards,<br>
Koen</p>
<div class="gmail_quote">On Feb 12, 2014 5:22 PM, &quot;Doron Fediuck&quot; &lt;<a href="mailto:dfediuck@redhat.com">dfediuck@redhat.com</a>&gt; wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<br>
<br>
----- Original Message -----<br>
&gt; From: &quot;René Koch&quot; &lt;<a href="mailto:rkoch@linuxland.at">rkoch@linuxland.at</a>&gt;<br>
&gt; To: &quot;Koen Vanoppen&quot; &lt;<a href="mailto:vanoppen.koen@gmail.com">vanoppen.koen@gmail.com</a>&gt;<br>
&gt; Cc: <a href="mailto:users@ovirt.org">users@ovirt.org</a><br>
&gt; Sent: Wednesday, February 12, 2014 4:18:37 PM<br>
&gt; Subject: Re: [Users] Memory usage<br>
&gt;<br>
&gt; On Wed, 2014-02-12 at 15:14 +0100, Koen Vanoppen wrote:<br>
&gt; &gt; In The GUI, it says it&#39;s using 25% of the memory.<br>
&gt;<br>
&gt;<br>
&gt; I guess it&#39;s the real value, right?<br>
&gt; The same happened for the memcached vm, someone reported to me -<br>
&gt; negative value in REST-API, but correct graph in oVirt webadmin GUI.<br>
&gt;<br>
&gt; I fear I have no idea how this can happen - so maybe someone else can<br>
&gt; help you troubleshoot this issue.<br>
&gt; &gt;<br>
&gt; &gt;<br>
&gt; &gt;<br>
&gt; &gt; 2014-02-12 15:10 GMT+01:00 Koen Vanoppen &lt;<a href="mailto:vanoppen.koen@gmail.com">vanoppen.koen@gmail.com</a>&gt;:<br>
&gt; &gt;         Thanks for the quick respons, but there is no memcached<br>
&gt; &gt;         running on that VM.<br>
&gt; &gt;<br>
&gt; &gt;<br>
&gt; &gt;         Kind regards<br>
&gt; &gt;<br>
&gt; &gt;<br>
&gt; &gt;<br>
&gt; &gt;         2014-02-12 15:06 GMT+01:00 René Koch &lt;<a href="mailto:rkoch@linuxland.at">rkoch@linuxland.at</a>&gt;:<br>
&gt; &gt;<br>
&gt; &gt;                 On Wed, 2014-02-12 at 14:55 +0100, Koen Vanoppen<br>
&gt; &gt;                 wrote:<br>
&gt; &gt;                 &gt; Dear all,<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt; When we monitor one of our machines, we noticed that<br>
&gt; &gt;                 there was one vm<br>
&gt; &gt;                 &gt; that was constantly giving a error of memory usage.<br>
&gt; &gt;                 But when we took a<br>
&gt; &gt;                 &gt; look at it, there is actually nothing wrong with it.<br>
&gt; &gt;                 Now we looked<br>
&gt; &gt;                 &gt; furhter then that. We looked at the API of the<br>
&gt; &gt;                 machine and noticed<br>
&gt; &gt;                 &gt; something very strange:<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt; &lt;statistic<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 href=&quot;/api/vms/3b9aa245-75ff-42e8-b921-1c9ce61826bf/statistics/b7499508-c1c3-32f0-8174-c1783e57bb08&quot;<br>
&gt; &gt;                 id=&quot;b7499508-c1c3-32f0-8174-c1783e57bb08&quot;&gt;&lt;name&gt;memory.used&lt;/name&gt;&lt;description&gt;Memory<br>
&gt; &gt;                 used (agent)&lt;/description&gt;&lt;values<br>
&gt; &gt;                 type=&quot;INTEGER&quot;&gt;&lt;value&gt;&lt;datum&gt;-944892806&lt;/datum&gt;&lt;/value&gt;&lt;/values&gt;&lt;type&gt;GAUGE&lt;/type&gt;&lt;unit&gt;BYTES&lt;/unit&gt;<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt; It&#39;s a negative...<br>
&gt; &gt;<br>
&gt; &gt;<br>
&gt; &gt;<br>
&gt; &gt;                 Do you have memcached running in this vm?<br>
&gt; &gt;<br>
&gt; &gt;                 I heard about this issue with memcached, but never<br>
&gt; &gt;                 tested memcached in<br>
&gt; &gt;                 my oVirt environment. You get the real usage value<br>
&gt; &gt;                 with<br>
&gt; &gt;                 memory.used = memory.installed + memory.used<br>
&gt; &gt;<br>
&gt; &gt;<br>
&gt; &gt;                 Regards,<br>
&gt; &gt;                 René<br>
&gt; &gt;<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt; What could be the problem?<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt; Kind regards,<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;                 &gt; koen<br>
&gt; &gt;                 &gt;<br>
&gt; &gt;<br>
<br>
Guys,<br>
these values are usually a result of overcommitment mechanism usage.<br>
For example, if KSM is effective, it will free a lot of memory pages,<br>
and total-free-committed becomes negative.<br>
<br>
This was reported in <a href="https://bugzilla.redhat.com/show_bug.cgi?id=977758" target="_blank">https://bugzilla.redhat.com/show_bug.cgi?id=977758</a><br>
and the engine is using memFree reported by vdsm, which is more accurate.<br>
<br>
The API reports the old version due to backwards compatibility.<br>
<br>
Doron<br>
<br>
P.S.<br>
René- thanks for helping!<br>
</blockquote></div>