| name | longhorn-volume-ops |
| description | Create, resize, clone, and tune per-volume Longhorn PVCs in anton. Use when adding a PVC backed by longhorn, overriding replica count or data locality for a specific workload, resizing an existing Longhorn volume, or cloning a volume from an existing PVC. Does not cover disk/node ops (longhorn-node-ops) or backup/restore (longhorn-backup-dr). |
longhorn-volume-ops
Per-volume Longhorn operations in anton.
Anton defaults
longhorn is the cluster default StorageClass (HelmRelease persistence.defaultClass: true).- 2 replicas,
dataLocality: best-effort, staleReplicaTimeout: 2880 minutes.
- Topology is asymmetric 2+1+2 (k8s-1: 2 disks, k8s-2: 1 disk, k8s-3: 2 disks). A 2-replica volume will skew toward k8s-1 + k8s-3 until the k8s-2 second-NVMe followup lands (see
context/hardware.md).
- Authoritative decision:
context/adrs/0005-adopt-longhorn-for-block-storage.md.
- Talos platform gotchas live in longhorn-node-ops/references/talos.md.
When to use
- Adding a PVC that should live on Longhorn — usually nothing to do; the default SC covers it.
- Need different replica count or locality for a specific workload → author a per-workload StorageClass.
- Resize an existing Longhorn PVC — online expand is supported.
- Clone from an existing PVC via
dataSource.
Recipes
Default PVC
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: <name>
namespace: <ns>
spec:
accessModes: [ReadWriteOnce]
resources:
requests:
storage: 20Gi
3-replica override via custom StorageClass
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: longhorn-3r
provisioner: driver.longhorn.io
parameters:
numberOfReplicas: "3"
dataLocality: best-effort
staleReplicaTimeout: "2880"
allowVolumeExpansion: true
reclaimPolicy: Delete
volumeBindingMode: Immediate
Note: anton's 2+1+2 topology has only 3 nodes. 3-replica is feasible cluster-wide but only k8s-1/k8s-3 can host two replicas each; k8s-2's single disk is the hard ceiling on spreading.
Online resize
Edit the PVC's spec.resources.requests.storage upward. Longhorn resizes the engine + replicas online for RWO. Filesystem resize runs at next pod restart for some drivers — verify with kubectl get pvc and inside-pod df -h.
Clone from existing PVC
spec:
dataSource:
kind: PersistentVolumeClaim
name: <source-pvc>
resources:
requests:
storage: 20Gi
References
