Re: [Users] Memory usage

From: "Koen Vanoppen" <vanoppen.koen(a)gmail.com&gt; To: users(a)ovirt.org Sent: Thursday, February 13, 2014 12:18:24 PM Subject: Re: [Users] Memory usage We can't turn off the memory balloon option because we are running the 3.3.2 with the bug of the memory balloon. Thx for the help!

On Feb 13, 2014 10:51 AM, "Doron Fediuck" < dfediuck(a)redhat.com > wrote: ----- Original Message ----- > From: "René Koch" < rkoch(a)linuxland.at > > To: "Doron Fediuck" < dfediuck(a)redhat.com > > Cc: "Koen Vanoppen" < vanoppen.koen(a)gmail.com >, users(a)ovirt.org , "Martin > Sivak" < msivak(a)redhat.com > > Sent: Thursday, February 13, 2014 11:16:27 AM > Subject: Re: [Users] Memory usage > > On Thu, 2014-02-13 at 03:49 -0500, Doron Fediuck wrote: > > > > ----- Original Message ----- > > > From: "René Koch" < rkoch(a)linuxland.at > > > > To: "Doron Fediuck" < dfediuck(a)redhat.com > > > > Cc: "Koen Vanoppen" < vanoppen.koen(a)gmail.com >, users(a)ovirt.org , > > > "Martin > > > Sivak" < msivak(a)redhat.com > > > > Sent: Wednesday, February 12, 2014 7:31:47 PM > > > Subject: Re: [Users] Memory usage > > > > > > On Wed, 2014-02-12 at 11:22 -0500, Doron Fediuck wrote: > > > > > > > > ----- 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. > > > > > > > > > Thanks a lot for the information. > > > > > > > > > > > > > > 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. > > > > > > > > > I just had a look at the bugzilla report and the RHEV documentation > > > which says "Current memory in bytes used by the virtual machine.". > > > So this means, the reported values are totally useless for monitoring > > > memory usage of a virtual machine if KSM is active. I would expect to > > > get the memory usage of a virtual machine and not how much memory is > > > consumed on the hypervisor (this is pretty useless information for me). > > > > > > Is it planned to report the memory usage in a virtual machine in the > > > API > > > as well? > > > > > > > > > Regards, > > > René > > > > > > > > > > René, > > started digging into this, but it may take some time. > > > > Note that there are 2 memory usage reports; one for the host, > > and another for each VM. > > My response is related to the host, while the original question was > > for the VM. I still think the root cause is the same (ie- related to > > overcommitment; for example the VM may have a balloon inflated), but > > would like to properly check and fix if needed. > > > Yes, I know. So my question was if we can add another value for the > usage in the vm in addition to the usage of the vm on the host. > We'll know once we understand the cause- ie is it a bug needs fixing or should we indeed add another value If you have a setup with this issue, try removing the balloon device and see if it helps / changes. > > > > > In order to make sure we keep track of it, please open a bug with all the > > relevant info. > > > > I'll open a bug for this. > Thanks > > > Thanks and keep reporting! > > Doron > > > _______________________________________________ Users mailing list Users(a)ovirt.org http://lists.ovirt.org/mailman/listinfo/users