Rook set filesystem type in StorageClass ceph-filesystem

Question

I have deployed rook using the official helm charts.

On my Kubernetes nodes, the host filesystem is xfs, but rook by default expects an ext4 filesystem.

So I overwrote the parameter cephFileSystems[0].storageClass.parameters.csi.storage.k8s.io/fstype in the helm chart with the value xfs.

But now, helm generates a Kubernetes manifest of

allowVolumeExpansion: true
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  annotations:
    storageclass.kubernetes.io/is-default-class: 'false'
  labels:
    argocd.argoproj.io/instance: rook-operator
  name: ceph-filesystem
parameters:
  clusterID: rook-ceph
  csi:
    storage:
      k8s:
        io/fstype: xfs
[...]

But the CRD io.k8s.api.storage.v1.StorageClass in Kubernetes does not accept it with the error:

error validating data: ValidationError(StorageClass.parameters.csi): invalid type for io.k8s.api.storage.v1.StorageClass.parameters: got "map", expected "string"

How do I correctly set xfs as filesystem for the OSDs?

Thanks in advance.

Best regards, rforberger

Answer 1

I think I solved it myself.

I changed

csi.storage.k8s.io/fstype: xfs

to

"csi.storage.k8s.io/fstype": xfs

in the values.yaml file of the official rook-ceph-cluster helm chart.

This way the generated manifest looks like:

# Source: rook-ceph-cluster/templates/cephfilesystem.yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ceph-filesystem
  annotations:
    storageclass.kubernetes.io/is-default-class: "false"
provisioner: rook-ceph.cephfs.csi.ceph.com
parameters:
  fsName: ceph-filesystem
  pool: ceph-filesystem-data0
  clusterID: default
  csi.storage.k8s.io/controller-expand-secret-name: rook-csi-cephfs-provisioner
  csi.storage.k8s.io/controller-expand-secret-namespace: rook-ceph
  csi.storage.k8s.io/node-stage-secret-name: rook-csi-cephfs-node
  csi.storage.k8s.io/node-stage-secret-namespace: rook-ceph
  csi.storage.k8s.io/provisioner-secret-name: rook-csi-cephfs-provisioner
  csi.storage.k8s.io/provisioner-secret-namespace: rook-ceph
  csi.storage.k8s.io/fstype: xfs
reclaimPolicy: Delete
allowVolumeExpansion: true

which is fine.