Kubernetes Error Code FailedScheduling: How to Fix It

Q: What does 'untolerated taint' mean in Kubernetes?

An untolerated taint means a node has a taint (a restriction) that prevents pods from being scheduled on it, and your pod doesn't have a matching toleration to override that restriction.

Q: How do I see what taints are on my Kubernetes nodes?

Use the command 'kubectl get nodes -o custom-columns=NAME:.metadata.name,TAINTS:.spec.taints' to see all node taints, or 'kubectl describe node [node-name]' for detailed information about a specific node.

Q: Can I remove all taints from a Kubernetes node?

Yes, but be careful. Some taints are there for important reasons like marking master nodes or nodes with specific hardware. Use 'kubectl taint nodes [node-name] [taint-key]-' to remove specific taints.

Q: What's the difference between NoSchedule and NoExecute taint effects?

NoSchedule prevents new pods from being scheduled on the node but doesn't affect existing pods. NoExecute will evict existing pods that don't tolerate the taint and prevent new ones from being scheduled.

Q: How do I add tolerations to all pods in a deployment?

Edit the deployment YAML file and add the tolerations section under 'spec.template.spec'. When you apply the changes with 'kubectl apply', all new pods will have the tolerations.

Abstract

The Kubernetes FailedScheduling error with 'node(s) had untolerated taint' occurs when a pod cannot be scheduled on any available nodes because those nodes have taints that the pod doesn't tolerate. This prevents the pod from running until you either add the appropriate tolerations to the pod or remove the taints from the nodes.