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kuberneteskubernetes-pvc

Kubernetes Unable to mount volumes for pod

I'm trying to setup a volume to use with Mongo on k8s.

I use kubectl create -f pv.yaml to create the volume.

pv.yaml:

kind: PersistentVolume
apiVersion: v1
metadata:
  name: pvvolume
  labels:
    type: local
spec:
  storageClassName: standard
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/nfs"
  claimRef:
    kind: PersistentVolumeClaim
    namespace: default
    name: pvvolume

I then deploy this StatefulSet that has pods making PVCs to this volume.

My volume seems to have been created without problem, I'm expecting it to just use the storage of the host node.

When I try to deploy I get the following error:

Unable to mount volumes for pod "mongo-0_default(2735bc71-5201-11e8-804f-02dffec55fd2)": timeout expired waiting for volumes to attach/mount for pod "default"/"mongo-0". list of unattached/unmounted volumes=[mongo-persistent-storage]

Have a missed a step in setting up my persistent volume?

Solution

  • A persistent volume is just the declaration of availability of some storage inside your kubernetes cluster. There is no binding with your pod at this stage.

    Since your pod is deployed through a StatefulSet, there should be in your cluster one or more PersistentVolumeClaims which are the objects that connect a pod with a PersistentVolume.

    In order to manually bind a PV with a PVC you need to edit your PVC by adding the following in its spec section:

    volumeName: "<your persistent volume name>"

    Here an explanation on how this process works: https://docs.openshift.org/latest/dev_guide/persistent_volumes.html#persistent-volumes-volumes-and-claim-prebinding