Kubernetes Persistent Volume Claim Indefinitely in Pending State

Akash Krishnan picture Akash Krishnan · Jul 3, 2017 · Viewed 59.4k times · Source

I created a PersistentVolume sourced from a Google Compute Engine persistent disk that I already formatted and provision with data. Kubernetes says the PersistentVolume is available.

kind: PersistentVolume
apiVersion: v1
metadata:
  name: models-1-0-0
  labels:
    name: models-1-0-0
spec:
  capacity:
    storage: 200Gi
  accessModes:
    - ReadOnlyMany
  gcePersistentDisk:
    pdName: models-1-0-0
    fsType: ext4
    readOnly: true

I then created a PersistentVolumeClaim so that I could attach this volume to multiple pods across multiple nodes. However, kubernetes indefinitely says it is in a pending state.

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: models-1-0-0-claim
spec:
  accessModes:
    - ReadOnlyMany
  resources:
    requests:
      storage: 200Gi
  selector:
    matchLabels:
      name: models-1-0-0

Any insights? I feel there may be something wrong with the selector...

Is it even possible to preconfigure a persistent disk with data and have pods across multiple nodes all be able to read from it?

Answer

Akash Krishnan picture Akash Krishnan · Jul 3, 2017

I quickly realized that PersistentVolumeClaim defaults the storageClassName field to standard when not specified. However, when creating a PersistentVolume, storageClassName does not have a default, so the selector doesn't find a match.

The following worked for me:

kind: PersistentVolume
apiVersion: v1
metadata:
  name: models-1-0-0
  labels:
    name: models-1-0-0
spec:
  capacity:
    storage: 200Gi
  storageClassName: standard
  accessModes:
    - ReadOnlyMany
  gcePersistentDisk:
    pdName: models-1-0-0
    fsType: ext4
    readOnly: true
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: models-1-0-0-claim
spec:
  accessModes:
    - ReadOnlyMany
  resources:
    requests:
      storage: 200Gi
  selector:
    matchLabels:
      name: models-1-0-0