Node selector constraints can prevent the scheduler from live-migrating a virtual machine to a target node. This often indicates a mismatch between the virtual machine's requirements and the node's capabilities.
A node selector may require a specific CPU feature, but the target node lacks the corresponding label (for example, cpu-feature.node.kubevirt.io/fpu: "true"). This mismatch can occur when the host-model CPU models and features computed by KubeVirt change over time.
You can resolve this issue using four different approaches.
Reboot the virtual machine.
KubeVirt automatically adds node selectors (during a previous migration or initial start) that can restrict scheduling. You can clear these node selectors by rebooting the virtual machine.
Reboot the virtual machine and set up a common CPU model.
You can override KubeVirt's default host-model CPU configuration by setting up a common CPU model for virtual machine migration. The model is applied to the virtual machine as its domain CPU, and to the pod as its node selector configuration.
This is the recommended approach for environments that can tolerate restarting of virtual machines.
Modify the node labels.
If rebooting the virtual machine is not an option, you can manually manipulate the target node's labels to satisfy the scheduling requirements.
Add the node-labeller.kubevirt.io/skip-node="true" annotation to the target node.
This annotation, which persists even after upgrades, prevents KubeVirt's node-labeller from automatically adding or removing CPU-related labels on this node.
The annotation itself does not affect the pod's node selector. It only controls the presence of specific CPU-related labels on the node, which the node selector checks against. For more information, see the References section.
Identify labels that are missing from the virtual machine's node selector and add them to the target node.
You can add the missing labels using the following command:
kubectl label node<node-name><key>=<value>
This circumvents the standard scheduling restrictions, allowing the virtual machine to migrate to the target node.
If a new node that lacks the required features is added to the cluster, you must repeat these steps to allow the virtual machine to live-migrate to that node.
Remove the node labels.
If you want to ensure that the virtual machine does not acquire specific node selector constraints after live migration, you can remove the relevant CPU labels from the target node.
Add the node-labeller.kubevirt.io/skip-node="true" annotation to the target node.
This annotation, which persists even after upgrades, prevents KubeVirt's node-labeller from automatically adding or removing CPU-related labels on this node.
This method works only if the virtual machine's pod does not have an existing node selector that contains the labels listed in the References section. Otherwise, you must reboot the virtual machine to clear the constraints.
Check if the pod has a node selector.
kubectl get pod <pod-name> -o yaml |grep nodeSelector -A 5 -B 5
If no node selector exists, remove the relevant CPU labels from the node.
Performing this action prevents the pod from acquiring new node selector constraints, thus enabling its future migration to other nodes. However, the successful outcome of that migration is not guaranteed.
Harvester doesn't directly schedule a VM in Kubernetes, it relies on KubeVirt to create the custom resource VirtualMachine. When the request to create a new VM is sent, a VirtualMachineInstance object is created and it creates the corresponding Pod.
The whole VM creation processt leverages kube-scheduler, which allows Harvester to use nodeSelector, affinity, and resources request/limitation to influence where a VM will be deployed.
How does kube-scheduler decide where to deploy a VM?
Finally, kube-scheduler calculates the scores from the plugins results for each Node, and select the Node with the highest score to deploy the Pod.
For example, let's say we have a three nodes Harvester cluster with 6 cores CPU and 16G RAM each, and we want to deploy a VM with 1 CPU and 1G RAM (without resources overcommit).
kube-scheduler will summarize the scores, as displayed in Table 1 below, and will select the node with the highest score, harvester-node-2 in this case, to deploy the VM.
kube-scheduler logs
virt-launcher-vm-without-overcommit-75q9b -> harvester-node-0: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9960 memory:15166603264] ,score 0, virt-launcher-vm-without-overcommit-75q9b -> harvester-node-1: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5560 memory:6352273408] ,score 45, virt-launcher-vm-without-overcommit-75q9b -> harvester-node-2: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5350 memory:5941231616] ,score 46, virt-launcher-vm-without-overcommit-75q9b -> harvester-node-0: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9960 memory:15166603264] ,score 4, virt-launcher-vm-without-overcommit-75q9b -> harvester-node-1: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5560 memory:6352273408] ,score 34, virt-launcher-vm-without-overcommit-75q9b -> harvester-node-2: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5350 memory:5941231616] ,score 37, "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="ImageLocality" node="harvester-node-0" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="ImageLocality" node="harvester-node-1" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="ImageLocality" node="harvester-node-2" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="InterPodAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="InterPodAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="InterPodAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeResourcesLeastAllocated" node="harvester-node-0" score=4 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeResourcesLeastAllocated" node="harvester-node-1" score=34 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeResourcesLeastAllocated" node="harvester-node-2" score=37 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodePreferAvoidPods" node="harvester-node-0" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodePreferAvoidPods" node="harvester-node-2" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodePreferAvoidPods" node="harvester-node-1" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="PodTopologySpread" node="harvester-node-0" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="PodTopologySpread" node="harvester-node-1" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="PodTopologySpread" node="harvester-node-2" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="TaintToleration" node="harvester-node-0" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="TaintToleration" node="harvester-node-1" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="TaintToleration" node="harvester-node-2" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeResourcesBalancedAllocation" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeResourcesBalancedAllocation" node="harvester-node-1" score=45 "Plugin scored node for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" plugin="NodeResourcesBalancedAllocation" node="harvester-node-2" score=46 "Calculated node's final score for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" node="harvester-node-0" score=1000358 "Calculated node's final score for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" node="harvester-node-1" score=1000433 "Calculated node's final score for pod" pod="default/virt-launcher-vm-without-overcommit-75q9b" node="harvester-node-2" score=1000437 AssumePodVolumes for pod "default/virt-launcher-vm-without-overcommit-75q9b", node "harvester-node-2" AssumePodVolumes for pod "default/virt-launcher-vm-without-overcommit-75q9b", node "harvester-node-2": all PVCs bound and nothing to do "Attempting to bind pod to node" pod="default/virt-launcher-vm-without-overcommit-75q9b" node="harvester-node-2"
Table 1 - kube-scheduler scores example
harvester-node-0
harvester-node-1
harvester-node-2
ImageLocality
54
54
54
InterPodAffinity
0
0
0
NodeResourcesLeastAllocated
4
34
37
NodeAffinity
0
0
0
NodePreferAvoidPods
1000000
1000000
1000000
PodTopologySpread
200
200
200
TaintToleration
100
100
100
NodeResourcesBalancedAllocation
0
45
46
Total
1000358
1000433
1000437
Why VMs are distributed unevenly with overcommit?
With resources overcommit, Harvester modifies the resources request. By default, the overcommit configuration is {"cpu": 1600, "memory": 150, "storage": 200}. This means that if we request a VM with 1 CPU and 1G RAM, its resources.requests.cpu will become 62m.
!!! note
The unit suffix m stands for "thousandth of a core."
To explain it, let's take the case of CPU overcommit. The default value of 1 CPU is equal to 1000m CPU, and with the default overcommit configuration of "cpu": 1600, the CPU resource will be 16x smaller. Here is the calculation: 1000m * 100 / 1600 = 62m.
Now, we can see how overcommitting influences kube-scheduler scores.
In this example, we use a three nodes Harvester cluster with 6 cores and 16G RAM each. We will deploy two VMs with 1 CPU and 1G RAM, and we will compare the scores for both cases of "with-overcommit" and "without-overcommit" resources.
The results of both tables Table 2 and Table 3 can be explained as follow:
In the "with-overcommit" case, both VMs are deployed on harvester-node-2, however in the "without-overcommit" case, the VM1 is deployed on harvester-node-2, and VM2 is deployed on harvester-node-1.
If we look at the detailed scores, we'll see a variation of Total Score for harvester-node-2 from 1000459 to 1000461 in the "with-overcommit" case, and 1000437 to 1000382 in the "without-overcommit case". It's because resources overcommit influences request-cpu and request-memory.
In the "with-overcommit" case, the request-cpu changes from 4412m to 4474m. The difference between the two numbers is 62m, which is what we calculated above. However, in the "without-overcommit" case, we send real requests to kube-scheduler, so the request-cpu changes from 5350m to 6350m.
Finally, since most plugins give the same scores for each node except NodeResourcesBalancedAllocation and NodeResourcesLeastAllocated, we'll see a difference of these two scores for each node.
From the results, we can see the overcommit feature influences the final score of each Node, so VMs are distributed unevenly. Although the harvester-node-2 score for VM 2 is higher than VM 1, it's not always increasing. In Table 4, we keep deploying VM with 1 CPU and 1G RAM, and we can see the score of harvester-node-2 starts decreasing from 11th VM. The behavior of kube-scheduler depends on your cluster resources and the workload you deployed.
kube-scheduler logs for vm1-with-overcommit
virt-launcher-vm1-with-overcommit-ljlmq -> harvester-node-0: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9022 memory:14807289856] ,score 0, virt-launcher-vm1-with-overcommit-ljlmq -> harvester-node-1: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:4622 memory:5992960000] ,score 58, virt-launcher-vm1-with-overcommit-ljlmq -> harvester-node-2: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:4412 memory:5581918208] ,score 59, virt-launcher-vm1-with-overcommit-ljlmq -> harvester-node-0: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9022 memory:14807289856] ,score 5, virt-launcher-vm1-with-overcommit-ljlmq -> harvester-node-1: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:4622 memory:5992960000] ,score 43, virt-launcher-vm1-with-overcommit-ljlmq -> harvester-node-2: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:4412 memory:5581918208] ,score 46, "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="InterPodAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="InterPodAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="InterPodAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeResourcesLeastAllocated" node="harvester-node-0" score=5 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeResourcesLeastAllocated" node="harvester-node-1" score=43 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeResourcesLeastAllocated" node="harvester-node-2" score=46 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodePreferAvoidPods" node="harvester-node-0" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodePreferAvoidPods" node="harvester-node-1" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodePreferAvoidPods" node="harvester-node-2" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="PodTopologySpread" node="harvester-node-0" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="PodTopologySpread" node="harvester-node-1" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="PodTopologySpread" node="harvester-node-2" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="TaintToleration" node="harvester-node-0" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="TaintToleration" node="harvester-node-1" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="TaintToleration" node="harvester-node-2" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeResourcesBalancedAllocation" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeResourcesBalancedAllocation" node="harvester-node-1" score=58 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="NodeResourcesBalancedAllocation" node="harvester-node-2" score=59 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="ImageLocality" node="harvester-node-0" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="ImageLocality" node="harvester-node-1" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" plugin="ImageLocality" node="harvester-node-2" score=54 "Calculated node's final score for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" node="harvester-node-0" score=1000359 "Calculated node's final score for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" node="harvester-node-1" score=1000455 "Calculated node's final score for pod" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" node="harvester-node-2" score=1000459 AssumePodVolumes for pod "default/virt-launcher-vm1-with-overcommit-ljlmq", node "harvester-node-2" AssumePodVolumes for pod "default/virt-launcher-vm1-with-overcommit-ljlmq", node "harvester-node-2": all PVCs bound and nothing to do "Attempting to bind pod to node" pod="default/virt-launcher-vm1-with-overcommit-ljlmq" node="harvester-node-2"
kube-scheduler logs for vm2-with-overcommit
virt-launcher-vm2-with-overcommit-pwrx4 -> harvester-node-0: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9022 memory:14807289856] ,score 0, virt-launcher-vm2-with-overcommit-pwrx4 -> harvester-node-1: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:4622 memory:5992960000] ,score 58, virt-launcher-vm2-with-overcommit-pwrx4 -> harvester-node-2: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:4474 memory:6476701696] ,score 64, virt-launcher-vm2-with-overcommit-pwrx4 -> harvester-node-0: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9022 memory:14807289856] ,score 5, virt-launcher-vm2-with-overcommit-pwrx4 -> harvester-node-1: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:4622 memory:5992960000] ,score 43, virt-launcher-vm2-with-overcommit-pwrx4 -> harvester-node-2: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:4474 memory:6476701696] ,score 43, "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodePreferAvoidPods" node="harvester-node-0" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodePreferAvoidPods" node="harvester-node-1" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodePreferAvoidPods" node="harvester-node-2" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="PodTopologySpread" node="harvester-node-0" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="PodTopologySpread" node="harvester-node-1" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="PodTopologySpread" node="harvester-node-2" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="TaintToleration" node="harvester-node-0" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="TaintToleration" node="harvester-node-1" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="TaintToleration" node="harvester-node-2" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeResourcesBalancedAllocation" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeResourcesBalancedAllocation" node="harvester-node-1" score=58 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeResourcesBalancedAllocation" node="harvester-node-2" score=64 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="ImageLocality" node="harvester-node-0" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="ImageLocality" node="harvester-node-1" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="ImageLocality" node="harvester-node-2" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="InterPodAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="InterPodAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="InterPodAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeResourcesLeastAllocated" node="harvester-node-0" score=5 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeResourcesLeastAllocated" node="harvester-node-1" score=43 "Plugin scored node for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" plugin="NodeResourcesLeastAllocated" node="harvester-node-2" score=43 "Calculated node's final score for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" node="harvester-node-0" score=1000359 "Calculated node's final score for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" node="harvester-node-1" score=1000455 "Calculated node's final score for pod" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" node="harvester-node-2" score=1000461 AssumePodVolumes for pod "default/virt-launcher-vm2-with-overcommit-pwrx4", node "harvester-node-2" AssumePodVolumes for pod "default/virt-launcher-vm2-with-overcommit-pwrx4", node "harvester-node-2": all PVCs bound and nothing to do "Attempting to bind pod to node" pod="default/virt-launcher-vm2-with-overcommit-pwrx4" node="harvester-node-2"
kube-scheduler logs for vm1-without-overcommit
virt-launcher-vm1-with-overcommit-6xqmq -> harvester-node-0: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9960 memory:15166603264] ,score 0, virt-launcher-vm1-with-overcommit-6xqmq -> harvester-node-1: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5560 memory:6352273408] ,score 45, virt-launcher-vm1-with-overcommit-6xqmq -> harvester-node-2: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5350 memory:5941231616] ,score 46, virt-launcher-vm1-with-overcommit-6xqmq -> harvester-node-0: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9960 memory:15166603264] ,score 4, virt-launcher-vm1-with-overcommit-6xqmq -> harvester-node-1: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5560 memory:6352273408] ,score 34, virt-launcher-vm1-with-overcommit-6xqmq -> harvester-node-2: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5350 memory:5941231616] ,score 37, "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="InterPodAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="InterPodAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="InterPodAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeResourcesLeastAllocated" node="harvester-node-0" score=4 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeResourcesLeastAllocated" node="harvester-node-1" score=34 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeResourcesLeastAllocated" node="harvester-node-2" score=37 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodePreferAvoidPods" node="harvester-node-0" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodePreferAvoidPods" node="harvester-node-1" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodePreferAvoidPods" node="harvester-node-2" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="PodTopologySpread" node="harvester-node-0" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="PodTopologySpread" node="harvester-node-1" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="PodTopologySpread" node="harvester-node-2" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="TaintToleration" node="harvester-node-0" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="TaintToleration" node="harvester-node-1" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="TaintToleration" node="harvester-node-2" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeResourcesBalancedAllocation" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeResourcesBalancedAllocation" node="harvester-node-1" score=45 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="NodeResourcesBalancedAllocation" node="harvester-node-2" score=46 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="ImageLocality" node="harvester-node-0" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="ImageLocality" node="harvester-node-1" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" plugin="ImageLocality" node="harvester-node-2" score=54 "Calculated node's final score for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" node="harvester-node-0" score=1000358 "Calculated node's final score for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" node="harvester-node-1" score=1000433 "Calculated node's final score for pod" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" node="harvester-node-2" score=1000437 AssumePodVolumes for pod "default/virt-launcher-vm1-with-overcommit-6xqmq", node "harvester-node-2" AssumePodVolumes for pod "default/virt-launcher-vm1-with-overcommit-6xqmq", node "harvester-node-2": all PVCs bound and nothing to do "Attempting to bind pod to node" pod="default/virt-launcher-vm1-with-overcommit-6xqmq" node="harvester-node-2"
kube-scheduler logs for vm2-without-overcommit
virt-launcher-vm2-without-overcommit-mf5vk -> harvester-node-0: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9960 memory:15166603264] ,score 0, virt-launcher-vm2-without-overcommit-mf5vk -> harvester-node-1: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5560 memory:6352273408] ,score 45, virt-launcher-vm2-without-overcommit-mf5vk -> harvester-node-2: NodeResourcesBalancedAllocation, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:6350 memory:7195328512] ,score 0, virt-launcher-vm2-without-overcommit-mf5vk -> harvester-node-0: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:9960 memory:15166603264] ,score 4, virt-launcher-vm2-without-overcommit-mf5vk -> harvester-node-1: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:5560 memory:6352273408] ,score 34, virt-launcher-vm2-without-overcommit-mf5vk -> harvester-node-2: NodeResourcesLeastAllocated, map of allocatable resources map[cpu:6000 memory:16776437760], map of requested resources map[cpu:6350 memory:7195328512] ,score 28, "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="PodTopologySpread" node="harvester-node-0" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="PodTopologySpread" node="harvester-node-1" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="PodTopologySpread" node="harvester-node-2" score=200 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="TaintToleration" node="harvester-node-0" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="TaintToleration" node="harvester-node-1" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="TaintToleration" node="harvester-node-2" score=100 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeResourcesBalancedAllocation" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeResourcesBalancedAllocation" node="harvester-node-1" score=45 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeResourcesBalancedAllocation" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="ImageLocality" node="harvester-node-0" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="ImageLocality" node="harvester-node-1" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="ImageLocality" node="harvester-node-2" score=54 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="InterPodAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="InterPodAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="InterPodAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeResourcesLeastAllocated" node="harvester-node-0" score=4 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeResourcesLeastAllocated" node="harvester-node-1" score=34 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeResourcesLeastAllocated" node="harvester-node-2" score=28 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeAffinity" node="harvester-node-0" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeAffinity" node="harvester-node-1" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodeAffinity" node="harvester-node-2" score=0 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodePreferAvoidPods" node="harvester-node-0" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodePreferAvoidPods" node="harvester-node-1" score=1000000 "Plugin scored node for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" plugin="NodePreferAvoidPods" node="harvester-node-2" score=1000000 "Calculated node's final score for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" node="harvester-node-0" score=1000358 "Calculated node's final score for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" node="harvester-node-1" score=1000433 "Calculated node's final score for pod" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" node="harvester-node-2" score=1000382 AssumePodVolumes for pod "default/virt-launcher-vm2-without-overcommit-mf5vk", node "harvester-node-1" AssumePodVolumes for pod "default/virt-launcher-vm2-without-overcommit-mf5vk", node "harvester-node-1": all PVCs bound and nothing to do "Attempting to bind pod to node" pod="default/virt-launcher-vm2-without-overcommit-mf5vk" node="harvester-node-1"
There are many plugins in kube-scheduler which we can use to influence the scores. For example, we can add the podAntiAffinity plugin to avoid VMs with the same labels being deployed on the same node.
kube-scheduler is deployed as a static pod in Harvester. The file is under /var/lib/rancher/rke2/agent/pod-manifests/kube-scheduler.yaml in each Management Node. We can add - --v=10 to the kube-scheduler container to show score logs.
