OK, Thanks for the helpfull information. Learned something more again! Kind regards, Koen On Feb 12, 2014 5:22 PM, "Doron Fediuck" <dfediuck@redhat.com> wrote:
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 >
----- Original Message ----- 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!