StorageClass configuration

For the Cassandra database, hybrid runtime uses dynamically created persistent volumes to store data. To configure Cassandra properly, you must configure a StorageClass definition that is backed by a solid-state drive (SSD).

This topic explains how to create a new StorageClass that uses SSD and make it the default class. When Cassandra starts, it will use this default StorageClass.

Change the default StorageClass

The following steps explain how to create a StorageClass and make it the default class. For more information, see Change the default storage class in the Kubernetes documentation.

  1. Get the name of the current default StorageClass: 
    kubectl get sc

    For example: 

    kubectl get sc
  NAME                 PROVISIONER            AGE
  standard (default)   kubernetes.io/gce-pd   98d
  2. Describe the StorageClass named standard. Note that its type is pd-standard: 
    kubectl describe sc standard

    For example: 

    kubectl describe sc standard
  Name:                  standard
  IsDefaultClass:        Yes
  Annotations:           storageclass.beta.kubernetes.io/is-default-class=true
  Provisioner:           kubernetes.io/gce-pd
  Parameters:            type=pd-standard
  AllowVolumeExpansion:  <unset>
  MountOptions:          <none>
  ReclaimPolicy:         Delete
  VolumeBindingMode:     Immediate
  Events:                <none>
  3. Create a new file called storageclass.yaml.
  4. Add this code to the file. Note that the name of the new class is apigee-sc. You can use any name you like. Also, note that the storage type is pd-ssd: 
    ---
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: "apigee-sc"
provisioner: kubernetes.io/gce-pd
parameters:
  type: pd-ssd
  replication-type: none
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true
  5. Apply the new StorageClass to your Kubernetes cluster: 
    kubectl apply -f storageclass.yaml
  6. Execute the following two commands to change the default StorageClass: 
    kubectl patch storageclass standard \
  -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"false"}}}'
     
    kubectl patch storageclass apigee-sc \
  -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'
  7. Execute this command to verify that the new default StorageClass is called apigee-sc: 
    kubectl get sc

    For example: 

    kubectl get sc
  NAME                 PROVISIONER            AGE
  apigee-sc (default)  kubernetes.io/gce-pd   1d
  standard             kubernetes.io/gce-pd   98d