Using block devices in Kubernetes

2 min read · Beginner

Platform Engineer Developer

Edera supports native Kubernetes storage APIs. You can mount block devices directly into pods using standard PersistentVolumes—no special configuration required.

This means you can use local NVMe drives, CSI-managed volumes, or raw host block devices with Edera workloads the same way you would without Edera.

How it works

  1. Create a PersistentVolume pointing to your block device
  2. Create a PersistentVolumeClaim to request the storage
  3. Mount it in your pod with runtimeClassName: edera

Example: Local NVMe device

This example mounts a local NVMe device (/dev/nvme01) into an Edera-protected workload.

PersistentVolume 

kind: PersistentVolume
apiVersion: v1
metadata:
  name: local-raw-pv-rw
spec:
  volumeMode: Block
  capacity:
    storage: 5Gi
  local:
    path: /dev/nvme01
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Delete
  nodeAffinity:
    required:
      nodeSelectorTerms:
        - matchExpressions:
            - key: kubernetes.io/hostname
              operator: In
              values:
                - my-host

PersistentVolumeClaim 

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: block-pvc-rw
spec:
  accessModes:
    - ReadWriteOnce
  volumeMode: Block
  resources:
    requests:
      storage: 2Gi

Workload 

apiVersion: batch/v1
kind: Job
metadata:
  name: host-blockdev-rw-pv
spec:
  backoffLimit: 0
  template:
    spec:
      runtimeClassName: edera
      nodeSelector:
        kubernetes.io/hostname: my-host
      containers:
        - name: test
          image: alpine:latest
          command: ["/bin/sh", "-c"]
          args:
            - |
              echo "=== Blockdev Test ==="
              echo ""
              echo "1. Blockdev at /mnt/high-perf-dev:"
              if echo "test" > /mnt/high-perf-dev/test && [ -f /mnt/high-perf-dev/test ]; then
                  echo "   SUCCESS: Blockdev writable"
              else
                  echo "   FAILURE: Blockdev not present/writable"
                  exit 1
              fi              
          volumeDevices:
            - name: data
              devicePath: /mnt/high-perf-dev
      volumes:
        - name: data
          persistentVolumeClaim:
            claimName: block-pvc-rw
      restartPolicy: Never

The key elements:

  • runtimeClassName: edera - Runs the workload in an isolated Edera zone
  • volumeMode: Block - Uses raw block device access
  • volumeDevices - Mounts the block device at the specified path

Additional notes

Native Kubernetes storage APIs (PersistentVolumes and block devices) are supported starting in Edera v1.6.0

Non-Kubernetes use cases

If you’re running Edera outside of Kubernetes, see:

Further reading

Last updated on
Using a scratch disk with Edera