did you change the memory over commitment to higher percentage? On Tuesday, 8 September 2020, 03:38:23 am GMT+8, KISHOR K <smileyface.524(a)gmail.com&gt; wrote: Hi All, I'm new to Ovirt and not having a perfect experience with Ovirt yet. I ran into a strange issue today when I tried to create a new VM with 32GB in ovirt. VM creation basically due to an error, pasted below. Cannot run VM. There is no host that satisfies current scheduling constraints. See below for details:, The host host-01 did not satisfy internal filter Memory., The host host-01 did not satisfy internal filter Memory. After some troubleshooting, I found that there was enough available memory (around 120 GB free ) in the host to host new VM and there were around 10 VMs already running on this host. But, I noticed that ovirt is actually scheduling and creating VM based on "Max free Memory for scheduling new VMs" value, which seems to be set/updated based on total allocated memory for all VMs running on the host and it's not really the then consumed memory by running VMs. Can anyone help to explain if it is some kind of bug in ovirt or it expected behavior? If it is expected behavior, is there any possibility to change it to make sure VM is created based on actual free memory? Thanks a lot in advance for your support. /Kishore /Kishore _______________________________________________ Users mailing list -- users(a)ovirt.org To unsubscribe send an email to users-leave(a)ovirt.org Privacy Statement: https://www.ovirt.org/privacy-policy.html oVirt Code of Conduct: https://www.ovirt.org/community/about/community-guidelines/ List Archives: https://lists.ovirt.org/archives/list/users@ovirt.org/message/EZVZI225KR5...

Compute|Cluster|Edit your cluster| Optimization tab |Memory Optimization

What version of oVirt are you running, this seems to be an issue with older than 4.3.4 version. https://bugzilla.redhat.com/show_bug.cgi?id=1717007#c4

Hi, As others told you already, this is the expected behavior. The reason is very simple. All the VMs expect their allocated memory to be available and might try to use it. And when that happens and the memory is not there, the VMs will crash. That is not something you typically want. You can configure Memory over-commitment to allow this behavior. Typically for desktop VMs that are not all using all the memory at the same time. See for example the docs here https://www.ovirt.org/documentation/administration_guide/#memory_optimiza... and here https://www.ovirt.org/documentation/administration_guide/#Cluster_Optimiz... for explanation. I also recommend enabling at least one of Enable Memory Balloon Optimization and/or KSM control to allow nodes to rebalance free memory. You should also set the Guaranteed memory for VMs as explained in the above links to limit ballooning aggressivity. Best regards -- Martin Sivak ex-oVirt maintainer of this area On Mon, Sep 7, 2020 at 9:38 PM KISHOR K <smileyface.524(a)gmail.com&gt; wrote: