Chapter 6. Configure storage for OpenShift Container Platform services

Procedure

1. Create a Persistent Volume Claim for the Image Registry to use.

   1. In the OpenShift Web Console, click Storage Persistent Volume Claims.
   2. Set the Project to openshift-image-registry.

   3. Click Create Persistent Volume Claim.

      1. From the list of available storage classes retrieved above, specify the Storage Class with the provisioner openshift-storage.cephfs.csi.ceph.com.
      2. Specify the Persistent Volume Claim Name, for example, ocs4registry.
      3. Specify an Access Mode of Shared Access (RWX).
      4. Specify a Size of at least 100 GB.

      5. Click Create.

         Wait until the status of the new Persistent Volume Claim is listed as Bound.

2. Configure the cluster’s Image Registry to use the new Persistent Volume Claim.

   1. Click Administration Custom Resource Definitions.
   2. Click the Config custom resource definition associated with the imageregistry.operator.openshift.io group.
   3. Click the Instances tab.
   4. Beside the cluster instance, click the Action Menu (⋮) Edit Config.

   5. Add the new Persistent Volume Claim as persistent storage for the Image Registry.

      1. Add the following under spec:, replacing the existing storage: section if necessary.

           storage:
             pvc:
               claim: <new-pvc-name>

         For example:

           storage:
             pvc:
               claim: ocs4registry

      2. Click Save.

3. Verify that the new configuration is being used.

   1. Click Workloads Pods.
   2. Set the Project to openshift-image-registry.
   3. Verify that the new image-registry-* pod appears with a status of Running, and that the previous image-registry-* pod terminates.
   4. Click the new image-registry-* pod to view pod details.
   5. Scroll down to Volumes and verify that the registry-storage volume has a Type that matches your new Persistent Volume Claim, for example, ocs4registry.

Procedure

1. In the OpenShift Web Console, go to Workloads Config Maps.
2. Set the Project dropdown to openshift-monitoring.
3. Click Create Config Map.

4. Define a new cluster-monitoring-config Config Map using the following example.

   Replace the content in angle brackets (<, >) with your own values, for example, retention: 24h or storage: 40Gi.

   Replace the storageClassName with the storageclass that uses the provisioner openshift-storage.rbd.csi.ceph.com. In the example given below the name of the storageclass is ocs-storagecluster-ceph-rbd.

   Example cluster-monitoring-config Config Map

   apiVersion: v1
   kind: ConfigMap
   metadata:
     name: cluster-monitoring-config
     namespace: openshift-monitoring
   data:
     config.yaml: |
         prometheusK8s:
           retention: <time to retain monitoring files, e.g. 24h>
           volumeClaimTemplate:
             metadata:
               name: ocs-prometheus-claim
             spec:
               storageClassName: ocs-storagecluster-ceph-rbd
               resources:
                 requests:
                   storage: <size of claim, e.g. 40Gi>
         alertmanagerMain:
           volumeClaimTemplate:
             metadata:
               name: ocs-alertmanager-claim
             spec:
               storageClassName: ocs-storagecluster-ceph-rbd
               resources:
                 requests:
                   storage: <size of claim, e.g. 40Gi>

5. Click Create to save and create the Config Map.

Verification steps

1. Verify that the Persistent Volume Claims are bound to the pods.

   1. Go to Storage Persistent Volume Claims.
   2. Set the Project dropdown to openshift-monitoring.

   3. Verify that 5 Persistent Volume Claims are visible with a state of Bound, attached to three alertmanager-main-* pods, and two prometheus-k8s-* pods.

      Figure 6.1. Monitoring storage created and bound

      

2. Verify that the new alertmanager-main-* pods appear with a state of Running.

   1. Go to Workloads Pods.
   2. Click the new alertmanager-main-* pods to view the pod details.

   3. Scroll down to Volumes and verify that the volume has a Type, ocs-alertmanager-claim that matches one of your new Persistent Volume Claims, for example, ocs-alertmanager-claim-alertmanager-main-0.

      Figure 6.2. Persistent Volume Claims attached to alertmanager-main-* pod

      

3. Verify that the new prometheus-k8s-* pods appear with a state of Running.

   1. Click the new prometheus-k8s-* pods to view the pod details.

   2. Scroll down to Volumes and verify that the volume has a Type, ocs-prometheus-claim that matches one of your new Persistent Volume Claims, for example, ocs-prometheus-claim-prometheus-k8s-0.

      Figure 6.3. Persistent Volume Claims attached to prometheus-k8s-* pod