Volumes

Model Lustre exports as PersistentVolumes and understand RWX behavior.

1: Static PV workflow
2: Volume attributes and mount options

Klustre CSI focuses on static provisioning: you point a PV at an existing Lustre export, bind it to a PVC, and mount it into pods. Explore the topics below for the manifest workflow and mount attribute details.

1 - Static PV workflow

Define PersistentVolumes and PersistentVolumeClaims that reference Lustre exports.

1. Create the PersistentVolume

apiVersion: v1
kind: PersistentVolume
metadata:
  name: lustre-static-pv
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteMany
  storageClassName: klustre-csi-static
  persistentVolumeReclaimPolicy: Retain
  csi:
    driver: lustre.csi.klustrefs.io
    volumeHandle: lustre-static-pv
    volumeAttributes:
      source: 10.0.0.1@tcp0:/lustre-fs
      mountOptions: flock,user_xattr

volumeHandle just needs to be unique within the cluster; it is not used by the Lustre backend.
volumeAttributes.source carries the Lustre management target and filesystem path.

2. Bind with a PersistentVolumeClaim

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: lustre-static-pvc
spec:
  accessModes:
    - ReadWriteMany
  storageClassName: klustre-csi-static
  volumeName: lustre-static-pv
  resources:
    requests:
      storage: 10Gi

Even though Lustre capacity is managed outside Kubernetes, the storage field should match the PV so the binder succeeds.

3. Mount from workloads

volumes:
  - name: lustre
    persistentVolumeClaim:
      claimName: lustre-static-pvc
containers:
  - name: app
    image: busybox
    volumeMounts:
      - name: lustre
        mountPath: /mnt/lustre

Multiple pods can reference the same PVC because Lustre supports ReadWriteMany. Pods must schedule on labeled nodes (lustre.csi.klustrefs.io/lustre-client=true).

4. Cleanup

Deleting the PVC detaches pods but the PV remains because the reclaim policy is Retain. Manually delete the PV when you no longer need it.

2 - Volume attributes and mount options

Map Kubernetes fields to Lustre mount flags and behaviors.

`volumeAttributes`

Key	Example	Purpose
`source`	`10.0.0.1@tcp0:/lustre-fs`	Host(s) and filesystem path given to `mount.lustre`.
`mountOptions`	`flock,user_xattr`	Comma-separated Lustre mount flags.

Additional keys (e.g., subdir) can be added in the future; the driver simply passes the map to the Lustre helper script.

Storage class tuning

See the storage class reference for details on:

allowedTopologies – keep workloads on nodes with the Lustre label.
reclaimPolicy – typically Retain for static PVs.
mountOptions – defaults to flock and user_xattr, but you can add noatime, flock, user_xattr, etc.

Override mount options per volume by setting volumeAttributes.mountOptions. This is useful when a subset of workloads needs different locking semantics.

Access modes

Use ReadWriteMany for shared Lustre volumes.
ReadOnlyMany is supported when you only need read access.
ReadWriteOnce offers no benefit with Lustre; prefer RWX.

Lifecycle reminders

Klustre CSI does not provision or delete Lustre exports. Ensure the server-side directory exists and has the correct permissions.
Kubernetes capacity values are advisory. Quotas should be enforced on the Lustre server.
PersistentVolumeReclaimPolicy=Retain keeps PVs around after PVC deletion; clean them up manually to avoid dangling objects.