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