Description of problem: In https://gerrit.ovirt.org/#/c/80721/ we enable polling of balloon driver stats during vm creation. we use this information in Bug #1529271 to report memory stats. In 4.2 for already running vms we need to run manually "dommemstat --period 5 [vm-name] to receive the information. This RFE is about doing this during upgrade of vdsm for all running vms. How reproducible: update vdsm 4.1 to 4.2 with running vms check that vm xml includes stats field under memballoon: <memballoon model='virtio'> <stats period='5' /> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </memballoon>
Why would we change already running VMs? Cluster level 4.2 VMs will have this, <4.2 won't
We need to get vm memory statistics for the metrics store. As I understand only a restart of all vms will enable that, which we can't have as a requirement just for collecting vm metrics. This is a very important statistics and we must have it as part of 4.2. This fix should enable the collection without a need to restart the vms.
This can be avoided with the change in bug #1532692 . When we provide by default GA info the memory stats are included.