Postinstallation storage configuration

The following storage configuration tasks are mandatory:

  • You must configure a default storage class for your cluster. Otherwise, the cluster cannot receive automated boot source updates.

  • You must configure storage profiles if your storage provider is not recognized by CDI. A storage profile provides recommended storage settings based on the associated storage class.

Optional: You can configure local storage by using the hostpath provisioner (HPP).

See the storage configuration overview for more options, including configuring the Containerized Data Importer (CDI), data volumes, and automatic boot source updates.

Configuring local storage by using the HPP

When you install the OKD Virtualization Operator, the Hostpath Provisioner (HPP) Operator is automatically installed. The HPP Operator creates the HPP provisioner.

The HPP is a local storage provisioner designed for OKD Virtualization. To use the HPP, you must create an HPP custom resource (CR).

HPP storage pools must not be in the same partition as the operating system. Otherwise, the storage pools might fill the operating system partition. If the operating system partition is full, performance can be effected or the node can become unstable or unusable.

Creating a storage class for the CSI driver with the storagePools stanza

To use the hostpath provisioner (HPP) you must create an associated storage class for the Container Storage Interface (CSI) driver.

When you create a storage class, you set parameters that affect the dynamic provisioning of persistent volumes (PVs) that belong to that storage class. You cannot update a StorageClass object’s parameters after you create it.

Virtual machines use data volumes that are based on local PVs. Local PVs are bound to specific nodes. While a disk image is prepared for consumption by the virtual machine, it is possible that the virtual machine cannot be scheduled to the node where the local storage PV was previously pinned.

To solve this problem, use the Kubernetes pod scheduler to bind the persistent volume claim (PVC) to a PV on the correct node. By using the StorageClass value with volumeBindingMode parameter set to WaitForFirstConsumer, the binding and provisioning of the PV is delayed until a pod is created using the PVC.

Procedure

  1. Create a storageclass_csi.yaml file to define the storage class:

    1. apiVersion: storage.k8s.io/v1
    2. kind: StorageClass
    3. metadata:
    4.   name: hostpath-csi
    5. provisioner: kubevirt.io.hostpath-provisioner
    6. reclaimPolicy: Delete (1)
    7. volumeBindingMode: WaitForFirstConsumer (2)
    8. parameters:
    9.   storagePool: my-storage-pool (3)
    1The two possible reclaimPolicy values are Delete and Retain. If you do not specify a value, the default value is Delete.
    2The volumeBindingMode parameter determines when dynamic provisioning and volume binding occur. Specify WaitForFirstConsumer to delay the binding and provisioning of a persistent volume (PV) until after a pod that uses the persistent volume claim (PVC) is created. This ensures that the PV meets the pod’s scheduling requirements.
    3Specify the name of the storage pool defined in the HPP CR.

  2. Save the file and exit.

  3. Create the StorageClass object by running the following command:

    1. $ oc create -f storageclass_csi.yaml