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