Raw Block Devices
The Portworx CSI Driver supports both File and Block volume types in Kubernetes PVCs. While file has more supported features, block support for
ReadWriteOnly PVCs was added in Portworx Enterprise in version 2.8.0.
Use cases for Raw Block Devices
If your application has a requirement to consume a raw block device as opposed to a mounted filesystem, this is a perfect use case for Portworx CSI Raw Block devices.
Standard Portworx volumes are used when creating a Raw Block PVC, so all features (snapshotting, resizing, encryption, security, and so on) are all available out of the box for these types of volumes.
Create and use raw block PVCs
In this example we are using the
px-csi-db storage class out of the box. Please refer CSI Enabled Storage Classes for list of available CSI enabled storage classes offered by Portworx.
Create a PVC spec that references the portworx-csi-sc as seen below in a YAML file named
kind: PersistentVolumeClaim apiVersion: v1 metadata: name: px-csi-raw-block-pvc spec: volumeMode: Block storageClassName: px-csi-db accessModes: - ReadWriteOnce resources: requests: storage: 2Gi
raw-block-pvc.yamlspec to create the raw block PVC:
kubectl apply -f raw-block-pvc.yaml
Create a deployment SPEC that references the above raw block PVC in
apiVersion: apps/v1 kind: Deployment metadata: name: ioping spec: selector: matchLabels: app: ioping strategy: rollingUpdate: maxSurge: 1 maxUnavailable: 1 type: RollingUpdate replicas: 1 template: metadata: labels: app: ioping version: "1" spec: containers: - name: ioping image: hpestorage/ioping command: [ "ioping" ] args: [ "/dev/xvda" ] volumeDevices: - name: raw-device devicePath: /dev/xvda volumes: - name: raw-device persistentVolumeClaim: claimName: px-csi-raw-block-pvc
raw-block-deployment.yamlspec to create the deployment utilizing our raw block PVC:
kubectl apply -f raw-block-deployment.yaml