Storage

OpenEBS

OpenEBS provides a local PV (Persistent Volume) provisioner for the cluster. It creates hostpath-backed persistent volumes that store data directly on a node's local filesystem -- no replication, no network overhead.

Architecture

flowchart LR
    PROV[OpenEBS\nLocal PV Provisioner]
    PROV --> HP[openebs-hostpath\n/var/mnt/extra/openebs/local\nevery node but worker-07]
    PROV --> FAST[openebs-hostpath-fast\n/var/mnt/extra/openebs/fast\nworker-07 fast/extra]
    PROV --> RUN[openebs-hostpath-runners\n/var/mnt/runners/openebs/local\nworker-07 fast/runners]
    PROV --> MEDIA[openebs-hostpath-media\n/var/mnt/media/openebs/local\nworker-07 hdd/media]
    PROV --> MODELS[openebs-hostpath-models\n/var/mnt/models/openebs/local\nworker-ai-01 NVMe]

When to Use OpenEBS

OpenEBS local PVs are best suited for workloads that:

• Manage their own replication -- databases like PostgreSQL (via CloudNativePG) that handle data replication at the application level
• Need low-latency local I/O -- workloads where network storage overhead is unacceptable
• Are tolerant of node affinity -- pods using local PVs are bound to the node where the volume was created

Storage Classes

All classes use volumeBindingMode: WaitForFirstConsumer. openebs-hostpath comes from the Helm values; the other four are plain StorageClass manifests in the app directory.

Configuration

Namespace

The openebs namespace runs with privileged Pod Security Standards since the provisioner needs host filesystem access.

Helm Chart

OpenEBS is deployed via the official Helm chart (4.6.1) with only the local PV provisioner enabled:

localpv-provisioner:
  rbac:
    create: true
  localpv:
    image:
      registry: quay.io/
      repository: openebs/provisioner-localpv
    basePath: &hostPath /var/mnt/extra/openebs/local
  hostpathClass:
    enabled: true
    name: openebs-hostpath
    isDefaultClass: false
    basePath: *hostPath
    xfsQuota:
      enabled: true
    allowedTopologies:
      - matchLabelExpressions:
          - key: kubernetes.io/hostname
            values: [worker-01, worker-02, worker-03, worker-04, worker-05,
                     worker-06, worker-08, worker-09, worker-10, worker-ai-01]

zfs-localpv:
  enabled: false
lvm-localpv:
  enabled: false
mayastor:
  enabled: false
loki:
  enabled: false
alloy:
  enabled: false

Key settings:

Usage

To request a local PV, set the storageClassName:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: my-database-data
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: openebs-hostpath
  resources:
    requests:
      storage: 20Gi

Comparison with Rook Ceph