Reattaching Volumes to Pods in Kubernetes


In a typical Kubernetes environment, the seamless running of applications is facilitated by data persistence, which is usually achieved through the use of persistent volumes (PVs) and persistent volume claims (PVCs). This is highly useful in scenarios where the pod fails and needs to restart - data won't be lost since it's stored on the volume.

  1. PV (Persistent Volume): A Persistent Volume (PV) in Kubernetes is a piece of storage in the cluster that has been provisioned by an admin or dynamically provisioned using Storage Classes. It is a resource in the cluster, just like a node, and is independent of any pod that uses the PV. This object encapsulates the storage details, such as its type (i.e., NFS, iSCSI, AWS EBS, Azure Disk, GCE PD, etc.), size, and how it's connected.

  2. PVC (Persistent Volume Claim): A Persistent Volume Claim (PVC) is a request for storage by a user. It is similar to a pod in that pods consume node resources, and PVCs consume PV resources. PVCs can request specific sizes and access modes (e.g., they can be mounted once read/write or many times read-only). The underlying PV could either be manually pre-provisioned or dynamically provisioned on-demand. PVCs are specific to a namespace and can be requested by users.

  3. A Persistent Volume (PV) reclaim policy is a setting in Kubernetes that defines what happens to a PV after it has been released from its claim (the Persistent Volume Claim, or PVC). The reclaim policy of a PersistentVolume tells the cluster what to do with the volume after it has been released of its claim. The two main types of PV Reclaim Policies in Kubernetes are Reclaim and Delete. Choosing the correct reclaim policy allows administrators to manage resources effectively and prevent accidental data loss (using the Retain policy) or automate cleanup (using the Delete policy). 

In essence, PV and PVC are Kubernetes resources that allow you to mount storage volumes to your pods, ensuring data persistence across pod restarts or failures.


There are times when the connection between your pod and its old volume can be severed for several reasons - perhaps the pod has crashed, the node has failed, or some network-related issues have occurred. In such scenarios, reattaching the old volumes to the pods becomes necessary to ensure data persistence and avoid data loss.


  1. Verify the status of the pods and volumes: Use the commands kubectl get pods and kubectl get pv,pvc to check the status of the pods and volumes. Note if any volumes or pods are in a failed or unknown state.

  2. Review Pod and Volume Events: Use the kubectl describe pod [pod-name] and kubectl describe pv [volume-name], kubectl describe pvc [volume-claim-name] commands to gain a detailed insight into the events and status of your pod and volume.


  1. Recreate the pod: If your pod has crashed or failed for some reason, try recreating the pod using kubectl delete pod [pod-name] and then redeploy it using the existing deployment configuration.

  2. Reattach the volume: If the pod is running, but the volume is not attached (Released), use the command kubectl patch pv [your-pv-name] -p '{"spec":{"claimRef": null}}' to remove the claimRef, the PVC will bind to the PV automatically. 

  3. Recreate the PVC: If the PVC seems to be the issue, delete the PVC with kubectl delete pvc [pvc-name] and recreate it. Make sure the spec.volumeName in the PVC matches the name of the PV you want to bind to.

Additional info

Reattaching a volume requires a PersistentVolume to have a Retain persistentVolumeReclaimPolicy. If these steps don't solve the problem, it's possible that there's an issue with your specific Kubernetes installation or with the node itself. Please follow the Troubleshooting steps to collect relevant errors and events.

Please note that the process of attaching and detaching volumes may vary depending on the storage class and the storage provisioner you are using.

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