----- Original Message -----
From: "René Koch" <rkoch(a)linuxland.at>
To: "Koen Vanoppen" <vanoppen.koen(a)gmail.com>
Cc: users(a)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(a)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(a)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!