Using CephFS with Kubernetes: Static and Dynamic Persistent Volumes

This article introduces how to use CephFS in Kubernetes, covering both static and dynamic PersistentVolumes (PVs) and the necessary configuration files.

Static PVs are created by the cluster administrator; an example

apiVersion: v1
kind: PersistentVolume
metadata:
  name: cephfs-pv
spec:
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteMany
  cephfs:
    monitors:
      - 192.168.0.3:6789
    user: kube
    secretRef:
      name: secret-for-cephfs
    readOnly: false
  persistentVolumeReclaimPolicy: Recycle

definition is provided, followed by commands to create the PV and a corresponding PVC:

$ kubectl create -f cephfs-pv.yaml -n cephfs
persistentvolume "cephfs-pv" created
$ kubectl get pv -n cephfs

For dynamic provisioning, the community‑provided cephfs-provisioner is described, including its architecture, the required StorageClass, and RBAC setup. Sample YAML for the StorageClass and PVC are included:

#kubectl create -f class.yaml
# kubectl get sc -n cephfs
NAME   PROVISIONER        AGE
cephfs ceph.com/cephfs   33d

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-1
  annotations:
    volume.beta.kubernetes.io/storage-class: "cephfs"
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Gi

The guide also discusses common pitfalls such as default directory paths, volume group settings, and permission issues, offering solutions like modifying VOLUME_GROUP and adjusting mount permissions to avoid admin‑only restrictions.

Overall, the tutorial provides step‑by‑step instructions and code snippets to enable read‑write access to a CephFS volume from multiple pods within a deployment.