Kubernetes Persistent Volumes Not Mounting After Node Failure
When a Kubernetes node fails, Persistent Volumes (PVs) that were previously mounted to pods on that node may fail to remount automatically.
This is often due to underlying cloud storage or Kubernetes configuration issues.
Start by checking the status of the Persistent Volume Claims (PVCs) and Pods using kubectl get pvc and kubectl get pods.
If you notice that a PVC is not bound to a PV or the pod is stuck in a Pending state, there may be an issue with volume attachment or detachment.
Verify that the PV is available and not in a Released or Terminating state, as these states may indicate an issue with the underlying volume or cloud storage provider.
For cloud-managed storage (e.g., EBS, GCE Persistent Disk), ensure that the volume is properly reattached to a new node.
If not, manually reattach the volume through the cloud provider’s console or API.
Another potential cause is if the node that was hosting the pod has failed in a way that prevents Kubernetes from detecting it properly.
You can verify the node’s status using kubectl get nodes and check for any issues in the node's logs with kubectl describe node <node-name>.
If the node is marked as NotReady or in a SchedulingDisabled state, Kubernetes will not schedule pods on that node, preventing the PV from being mounted.
To fix this, either drain and delete the failed node or ensure that Kubernetes is able to schedule pods on a healthy node by using kubectl cordon or kubectl drain commands.
If the pod’s volume mount is still failing, check for network connectivity issues between Kubernetes nodes and the cloud storage service.
Network or API delays can prevent Kubernetes from detecting and resolving the volume mounting issue in a timely manner.
Additionally, check the kubelet logs on the node for any specific errors related to volume attachment.
If the issue persists after troubleshooting, consider setting up a PodDisruptionBudget to manage pod availability during node failures, which will ensure that pods are rescheduled properly even during node disruptions.
