Managing and allocating storage resources

Procedure

1. Log in to OpenShift Web Console.
2. Click Storage → Storage Classes.
3. Click Create Storage Class.
4. Enter the storage class Name and Description.
5. Select either Delete or Retain for the Reclaim Policy. By default, Delete is selected.
6. Select RBD Provisioner which is the plugin used for provisioning the persistent volumes.

7. You can either create a new pool or use an existing one.

   Create a new pool

   1. Enter a name for the pool.
   2. Choose 2-way-Replication or 3-way-Replication as the Data Protection Policy.

   3. Select Enable compression if you need to compress the data.

      Enabling compression can impact application performance and might prove ineffective when data to be written is already compressed or encrypted. Data written before enabling compression will not be compressed.

   4. Click Create to create the storage pool.
   5. Click Finish after the pool is created.
   6. Click Create to create the storage class.

   Use an existing pool

   1. Choose a pool from the list.
   2. Click Create to create the storage class with the selected pool.

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.

      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.

      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.

      Persistent Volume Claims attached to prometheus-k8s-* pod

      

Procedure

1. Create a Persistent Volume Claim (PVC) for the application to use.

   1. In OpenShift Web Console, click Storage → Persistent Volume Claims.
   2. Set the Project for the application pod.

   3. Click Create Persistent Volume Claim.

      1. Specify a Storage Class provided by OpenShift Container Storage.
      2. Specify the PVC Name, for example, myclaim.
      3. Select the required Access Mode.
      4. Specify a Size as per application requirement.
      5. Click Create and wait until the PVC is in Bound status.

2. Configure a new or existing application pod to use the new PVC.

   • For a new application pod, perform the following steps:

     1. Click Workloads →Pods.
     2. Create a new application pod.

     3. Under the spec: section, add volume: section to add the new PVC as a volume for the application pod.

        volumes:
          - name: <volume_name>
            persistentVolumeClaim:
              claimName: <pvc_name>

        For example:

        volumes:
          - name: mypd
            persistentVolumeClaim:
              claimName: myclaim

   • For an existing application pod, perform the following steps:

     1. Click Workloads →Deployment Configs.
     2. Search for the required deployment config associated with the application pod.
     3. Click on its Action menu (⋮) → Edit Deployment Config.

     4. Under the spec: section, add volume: section to add the new PVC as a volume for the application pod and click Save.

        volumes:
          - name: <volume_name>
            persistentVolumeClaim:
              claimName: <pvc_name>

        For example:

        volumes:
          - name: mypd
            persistentVolumeClaim:
              claimName: myclaim

3. Verify that the new configuration is being used.

   1. Click Workloads → Pods.
   2. Set the Project for the application pod.
   3. Verify that the application pod appears with a status of Running.
   4. Click the application pod name to view pod details.
   5. Scroll down to Volumes section and verify that the volume has a Type that matches your new Persistent Volume Claim, for example, myclaim.

Procedure

1. Log in to OpenShift Web Console.
2. Click Storage → Persistent Volume Claims
3. Search for the required PVC name by using the Filter textbox. You can also filter the list of PVCs by Name or Label to narrow down the list
4. Check the Status column corresponding to the required PVC.
5. Click the required Name to view the PVC details.

Procedure

1. Log in to OpenShift Web Console.
2. Click Home → Overview → Persistent Storage
3. Locate the Inventory card to see the number of PVCs with errors.
4. Click Storage → Persistent Volume Claims
5. Search for the required PVC using the Filter textbox.
6. Click on the PVC name and navigate to Events
7. Address the events as required or as directed.

Procedure

1. In OpenShift Web Console, navigate to Storage → Persistent Volume Claims.
2. Click the Action Menu (⋮) next to the Persistent Volume Claim you want to expand.

3. Click Expand PVC:

   

4. Select the new size of the Persistent Volume Claim, then click Expand:

   

5. To verify the expansion, navigate to the PVC’s details page and verify the Capacity field has the correct size requested.

   Note

   When expanding PVCs based on Ceph RADOS Block Devices (RBDs), if the PVC is not already attached to a pod the Condition type is FileSystemResizePending in the PVC’s details page. Once the volume is mounted, filesystem resize succeeds and the new size is reflected in the Capacity field.

Procedure

1. Click Storage → Persistent Volume Claims from the OpenShift Web Console.

2. To create a clone, do one of the following:

   • Beside the desired PVC, click Action menu (⋮) → Clone PVC.
   • Click on the PVC that you want to clone and click Actions → Clone PVC.
3. Enter a Name for the clone.

4. Click Clone. You will be redirected to the new PVC details page.

   Note

   Clones are created with the access mode of the parent PVC. Currently, you cannot specify the access mode using the OpenShift Web Console UI. However, you can specify the access mode from the CLI using the YAML. For more information, see Provisioning a CSI volume clone.

5. Wait for the cloned PVC status to become Bound.

   The cloned PVC is now available to be consumed by the pods. This cloned PVC is independent of its dataSource PVC.