Using pre-provisioned volumes in GCP Anthos

This document describes how to use a pre-provisioned volume in your cluster.

Create a Portworx volume using pxctl

First create a volume using the Portworx CLI. On one of the nodes with Portworx installed, run the following command:

/opt/pwx/bin/pxctl volume create testvol --size 2

For more details on creating volumes using pxctl, see Concepts.

Alternatively, you can also use snapshots that you previously created.

Use the Portworx volume

Once you have a Portworx volume, you can use it in 2 different ways:

1. Using the Portworx volume directly in a pod

You can create a pod that directly uses a Portworx volume as follows:

apiVersion: v1
kind: Pod
metadata:
   name: nginx-px
spec:
   containers:
   - image: nginx
     name: nginx-px
     volumeMounts:
     - mountPath: /test-portworx-volume
       name: testvol
   volumes:
   - name: testvol
     # This Portworx volume must already exist.
     portworxVolume:
       volumeID: testvol

note

The name and volumeID above must be the same and should be the name of the Portworx volume created using pxctl.

2. Using the Portworx volume by creating a PersistentVolume & PersistentVolumeClaim

Creating PersistentVolume

First create a PersistentVolume that references the Portworx volume. Following is an example spec.

apiVersion: v1
kind: PersistentVolume
metadata:
  name: testvol
spec:
  capacity:
    storage: 2Gi
  claimRef:
    apiVersion: v1
    kind: PersistentVolumeClaim
    name: testvol-pvc
    namespace: default
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  portworxVolume:
    volumeID: <px-volume-id>

note

The preceding PersistentVolume example references an existing Portworx volume called testvol that was created using pxctl.

Creating PersistentVolumeClaim

Now create a PersistentVolumeClaim that will claim the previously created volume. Following is an example spec.

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: testvol-pvc
spec:
  selector:
    matchLabels:
      name: testvol
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi
  volumeName: testvol

note

If you are planning to use the PersistentVolumeClaim in a pod in a non-default namespace, you must create the PersistentVolumeClaim in that namespace.

Creating a pod using the PersistentVolumeClaim

Now you can create a pod that references the PersistentVolumeClaim that you created. Following is an example.

apiVersion: v1
kind: Pod
metadata:
   name: nginx-px
spec:
  containers:
  - image: nginx
    name: nginx-px
    volumeMounts:
    - mountPath: /test-portworx-volume
      name: testvol
  volumes:
  - name: testvol
    persistentVolumeClaim:
      claimName: testvol-pvc

note

To access PV/PVCs with a non-root user, refer to Access via Non-Root Users