homelab/k8s/infrastructure/longhorn/longhorn-wffc-storageclass.yaml

# longhorn-wffc — Longhorn StorageClass with WaitForFirstConsumer binding.
#
# WaitForFirstConsumer defers PV binding until the pod is scheduled, ensuring the
# volume is provisioned on a node where the pod can actually run. Critical for HA:
# with 3-replica volumes spread across 3 nodes, the scheduler needs to see which
# nodes already have replicas before placing the pod, avoiding situations where
# the pod lands on a node that can't reach any replica.
#
# numberOfReplicas=3 provides true HA: each volume has 3 copies across 3 nodes.
# If one node fails, the remaining 2 nodes still have the data and can serve it.
# volumeBindingMode is immutable, so this is a distinct SC from the chart's default.
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: longhorn-wffc
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: driver.longhorn.io
allowVolumeExpansion: true
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer
parameters:
  numberOfReplicas: "3"
  staleReplicaTimeout: "30"
  fromBackup: ""
  dataLocality: "best-effort"