Using PowerVC storage with IBM Cloud Private

IBM® Cloud Private is an application platform for developing and managing on-premises, containerized applications. After installing IBM Cloud Private master and worker nodes on virtual machines deployed though PowerVC, containers can use storage backed by volumes managed through PowerVC. This has several benefits. You can dynamically increase or decrease the amount of storage available to the worker node as the deployed containers change. Additionally, one set of volumes can be shared by containers across multiple worker nodes.

For IBM Cloud Private to use PowerVC storage for deploy containers, you must install the ibm-powevc-k8s-volume-driver Helm chart. This Helm chart installs and configures the Kubernetes resources needed by the IBM PowerVC FlexVolume driver.

The PowerVC FlexVolume driver consists of the PowerVC Provisioner and a Kubernetes FlexVolume driver.

The PowerVC Provisioner is a Kubernetes external storage provisioner that is deployed in a container on the master node. It creates and deletes volumes through PowerVC when a persistent volume claim is created or deleted through IBM Cloud Private. The PowerVC FlexVolume driver is deployed as a DaemonSet to the master and all worker nodes. This FlexVolume driver attaches the volume to a worker node when a container is deployed using the persistent volume claim that the volume is backing, detaches the volume from the worker node when necessary, and mounts the volume to the worker node for the container to use. The FlexVolume driver architecture is described in the following figure.
Note: PowerVC must be managing any worker nodes that you want to use with the FlexVolume driver.
Figure 1. IBM Cloud Private with PowerVC and the PowerVC FlexVolume driver

Requirements

You must meet these requirements to use the FlexVolume driver. For full environment setup details, see the Helm chart information in IBM Cloud Private.
  • IBM Cloud Private 2.1.0.2 or later, or Kubernetes 1.9.1 or later
  • The Flex Volume directory must be mounted in the controller manager container. This is done for you in IBM Cloud Private 2.1.0.3 and later.
  • Only Fibre Channel attached storage is supported in PowerVC 1.4.0.