Chapter 3. Deploying OpenShift Container Storage on Red Hat OpenStack Platform in external mode

Red Hat OpenShift Container Storage can use an externally hosted Red Hat Ceph Storage (RHCS) cluster as the storage provider on Red Hat OpenStack Platform. See Planning your deployment for more information.

For instructions regarding how to install a RHCS 4 cluster, see Installation guide.

Follow these steps to deploy OpenShift Container Storage in external mode:

3.1. Installing Red Hat OpenShift Container Storage Operator

You can install Red Hat OpenShift Container Storage Operator using the Red Hat OpenShift Container Platform Operator Hub.

Prerequisites

  • Access to an OpenShift Container Platform cluster using an account with cluster-admin and operator installation permissions.
  • You have at least three worker nodes in the Red Hat OpenShift Container Platform cluster.
  • You have satisfied any additional requirements required. For more information, see Planning your deployment.
Note
  • When you need to override the cluster-wide default node selector for OpenShift Container Storage, you can use the following command to specify a blank node selector for the openshift-storage namespace (create openshift-storage namespace in this case):

    $ oc annotate namespace openshift-storage openshift.io/node-selector=
  • Taint a node as infra to ensure only Red Hat OpenShift Container Storage resources are scheduled on that node. This helps you save on subscription costs. For more information, see How to use dedicated worker nodes for Red Hat OpenShift Container Storage chapter in Managing and Allocating Storage Resources guide.

Procedure

  1. Log in to OpenShift Web Console.
  2. Click OperatorsOperatorHub.
  3. Search for OpenShift Container Storage from the list of operators and click on it.
  4. Click Install.
  5. Set the following options on the Install Operator page:

    1. Channel as stable-4.8.
    2. Installation Mode as A specific namespace on the cluster.
    3. Installed Namespace as Operator recommended namespace openshift-storage. If Namespace openshift-storage does not exist, it will be created during the operator installation.
    4. Approval Strategy as Automatic or Manual.
    5. Click Install.

      If you select Automatic updates, the Operator Lifecycle Manager (OLM) automatically upgrades the running instance of your operator without any intervention.

      If you select Manual updates, the OLM creates an update request. As a cluster administrator, you must then manually approve that update request to have the operator updated to the new version.

Verification step

  • Verify that the OpenShift Container Storage Operator shows a green tick indicating successful installation.

3.2. Creating an OpenShift Container Storage Cluster service for external mode

You need to create a new OpenShift Container Storage cluster service after you install OpenShift Container Storage operator on OpenShift Container Platform deployed on Red Hat OpenStack platform.

Prerequisites

  • Ensure the OpenShift Container Platform version is 4.8 or above before deploying OpenShift Container Storage 4.8.
  • OpenShift Container Storage operator must be installed. For more information, see Installing OpenShift Container Storage Operator using the Operator Hub.
  • Red Hat Ceph Storage version 4.2z1 or later is required for the external cluster. For more information, see this knowledge base article on Red Hat Ceph Storage releases and corresponding Ceph package versions.

    If you have updated the Red Hat Ceph Storage cluster from a version lower than 4.1.1 to the latest release and is not a freshly deployed cluster, you must manually set the application type for CephFS pool on the Red Hat Ceph Storage cluster to enable CephFS PVC creation in external mode.

    For more details, see Troubleshooting CephFS PVC creation in external mode.

  • Red Hat Ceph Storage must have Ceph Dashboard installed and configured. For more information, see Ceph Dashboard installation and access.
  • Red Hat recommends that the external Red Hat Ceph Storage cluster has the PG Autoscaler enabled. For more information, see The placement group autoscaler section in the Red Hat Ceph Storage documentation.
  • The external Ceph cluster should have an existing RBD pool pre-configured for use. If it does not exist, contact your Red Hat Ceph Storage administrator to create one before you move ahead with OpenShift Container Storage deployment. Red Hat recommends to use a separate pool for each OpenShift Container Storage cluster.

Procedure

  1. Click Operators → Installed Operators to view all the installed operators.

    Ensure that the Project selected is openshift-storage.

  2. Click OpenShift Container StorageCreate Instance link of Storage Cluster.
  3. Select Mode as External. By default, Internal is selected as deployment mode.

    Figure 3.1. Connect to external cluster section on Create Storage Cluster form

    Screenshot shows connect to external cluster section after you select mode as external where you can download the python script and then upload the RHCS json file.
  4. In the Connect to external cluster section, click on the Download Script link to download the python script for extracting Ceph cluster details.
  5. For extracting the Red Hat Ceph Storage (RHCS) cluster details, contact the RHCS administrator to run the downloaded python script on a Red Hat Ceph Storage node with admin key.

    1. Run the following command on the RHCS node to view the list of available arguments.

      # python3 ceph-external-cluster-details-exporter.py --help
      Important

      Use python instead of python3 if the Red Hat Ceph Storage 4.x cluster is deployed on Red Hat Enterprise Linux 7.x (RHEL 7.x) cluster.

      Note

      You can also run the script from inside a MON container (containerized deployment) or from a MON node (rpm deployment).

    2. To retrieve the external cluster details from the RHCS cluster, run the following command

      # python3 ceph-external-cluster-details-exporter.py \
      --rbd-data-pool-name <rbd block pool name>  [optional arguments]

      For example:

      # python3 ceph-external-cluster-details-exporter.py --rbd-data-pool-name ceph-rbd --monitoring-endpoint xxx.xxx.xxx.xxx --monitoring-endpoint-port xxxx --rgw-endpoint xxx.xxx.xxx.xxx:xxxx --run-as-user client.ocs

      In the above example,

      • --rbd-data-pool-name is a mandatory parameter used for providing block storage in OpenShift Container Storage.
      • --rgw-endpoint is optional. Provide this parameter if object storage is to be provisioned through Ceph Rados Gateway for OpenShift Container Storage. Provide the endpoint in the following format: <ip_address>:<port>
      • --monitoring-endpoint is optional. It is the IP address of the active ceph-mgr reachable from the OpenShift Container Platform cluster. If not provided, the value is automatically populated.
      • --monitoring-endpoint-port is optional. It is the port associated with the ceph-mgr Prometheus exporter specified by --monitoring-endpoint. If not provided, the value is automatically populated.
      • -- run-as-user is an optional parameter used for providing a name for the Ceph user which is created by the script. If this parameter is not specified, a default user name client.healthchecker is created. The permissions for the new user is set as:

        • caps: [mgr] allow command config
        • caps: [mon] allow r, allow command quorum_status, allow command version
        • caps: [osd] allow rwx pool=RGW_POOL_PREFIX.rgw.meta, allow r pool=.rgw.root, allow rw pool=RGW_POOL_PREFIX.rgw.control, allow rx pool=RGW_POOL_PREFIX.rgw.log, allow x pool=RGW_POOL_PREFIX.rgw.buckets.index

          Example of JSON output generated using the python script:

          [{"name": "rook-ceph-mon-endpoints", "kind": "ConfigMap", "data": {"data": "xxx.xxx.xxx.xxx:xxxx", "maxMonId": "0", "mapping": "{}"}}, {"name": "rook-ceph-mon", "kind": "Secret", "data": {"admin-secret": "admin-secret", "fsid": "<fs-id>", "mon-secret": "mon-secret"}}, {"name": "rook-ceph-operator-creds", "kind": "Secret", "data": {"userID": "client.healthchecker", "userKey": "<user-key>"}}, {"name": "rook-csi-rbd-node", "kind": "Secret", "data": {"userID": "csi-rbd-node", "userKey": "<user-key>"}}, {"name": "ceph-rbd", "kind": "StorageClass", "data": {"pool": "ceph-rbd"}}, {"name": "monitoring-endpoint", "kind": "CephCluster", "data": {"MonitoringEndpoint": "xxx.xxx.xxx.xxx", "MonitoringPort": "xxxx"}}, {"name": "rook-csi-rbd-provisioner", "kind": "Secret", "data": {"userID": "csi-rbd-provisioner", "userKey": "<user-key>"}}, {"name": "rook-csi-cephfs-provisioner", "kind": "Secret", "data": {"adminID": "csi-cephfs-provisioner", "adminKey": "<admin-key>"}}, {"name": "rook-csi-cephfs-node", "kind": "Secret", "data": {"adminID": "csi-cephfs-node", "adminKey": "<admin-key>"}}, {"name": "cephfs", "kind": "StorageClass", "data": {"fsName": "cephfs", "pool": "cephfs_data"}}, {"name": "ceph-rgw", "kind": "StorageClass", "data": {"endpoint": "xxx.xxx.xxx.xxx:xxxx", "poolPrefix": "default"}}]

    3. Save the JSON output to a file with .json extension

      Note

      For OpenShift Container Storage to work seamlessly, ensure that the parameters (RGW endpoint, CephFS details, RBD pool, and so on) to be uploaded using the JSON file remains unchanged on the RHCS external cluster after the storage cluster creation.

  6. Click External cluster metadata → Browse to select and upload the JSON file.

    The content of the JSON file is populated and displayed in the text box.

    Figure 3.2. Json file content

    Screenshot shows the content of the credentials file after it is uploaded
  7. Click Create.

    The Create button is enabled only after you upload the .json file.

Verification steps

  1. Verify that the final Status of the installed storage cluster shows as Phase: Ready with a green tick mark.

    • Click Operators → Installed Operators → Storage Cluster link to view the storage cluster installation status.
    • Alternatively, when you are on the Operator Details tab, you can click on the Storage Cluster tab to view the status.
  2. To verify that OpenShift Container Storage, pods and StorageClass are successfully installed, see Verifying your external mode OpenShift Container Storage installation.

3.3. Verifying your OpenShift Container Storage installation for external mode

Use this section to verify that OpenShift Container Storage is deployed correctly.

3.3.1. Verifying the state of the pods

  1. Click Workloads → Pods from the left pane of the OpenShift Web Console.
  2. Select openshift-storage from the Project drop down list.

    For more information on the expected number of pods for each component and how it varies depending on the number of nodes, see Table 3.1, “Pods corresponding to OpenShift Container Storage components”

  3. Verify that the following pods are in running state:

    Table 3.1. Pods corresponding to OpenShift Container Storage components

    ComponentCorresponding pods

    OpenShift Container Storage Operator

    • ocs-operator-* (1 pod on any worker node)
    • ocs-metrics-exporter-*

    Rook-ceph Operator

    rook-ceph-operator-*

    (1 pod on any worker node)

    Multicloud Object Gateway

    • noobaa-operator-* (1 pod on any worker node)
    • noobaa-core-* (1 pod on any worker node)
    • nooba-db-* (1 pod on any worker node)
    • noobaa-endpoint-* (1 pod on any worker node)

    CSI

    • cephfs

      • csi-cephfsplugin-* (1 pod on each worker node)
      • csi-cephfsplugin-provisioner-* (2 pods distributed across worker nodes)
    Note

    If an MDS is not deployed in the external cluster, the csi-cephfsplugin pods will not be created.

    • rbd

      • csi-rbdplugin-* (1 pod on each worker node)
      • csi-rbdplugin-provisioner-* (2 pods distributed across worker nodes)

3.3.2. Verifying that the OpenShift Container Storage cluster is healthy

  • Click Storage → Overview from the left pane of the OpenShift Web Console and click Block and File tab.
  • In the Status card, verify that Storage Cluster has a green tick mark.
  • In the Details card, verify that the cluster information is displayed as follows:

    Service Name
    OpenShift Container Storage
    Cluster Name
    ocs-external-storagecluster
    Provider
    OpenStack
    Mode
    External
    Version
    ocs-operator-4.8.0

For more information on the health of OpenShift Container Storage cluster using the Block and File dashboard, see Monitoring OpenShift Container Storage.

3.3.3. Verifying that the Multicloud Object Gateway is healthy

  • Click Storage → Overview from the left pane of the OpenShift Web Console and click the Object tab.
  • In the Status card, verify that both Object Service and Data Resiliency are in Ready state (green tick).

    Figure 3.3. Health status card in Object Dashboard

    Screenshot of Health card in object service dashboard
  • In the Details card, verify that the MCG information is displayed appropriately as follows:

    Service Name
    OpenShift Container Storage
    System Name

    Multicloud Object Gateway

    RADOS Object Gateway

    Provider
    OpenStack
    Version
    ocs-operator-4.8.0
Note

The RADOS Object Gateway is only listed in case RADOS Object Gateway endpoint details were included while deploying OpenShift Container Storage in external mode.

For more information on the health of OpenShift Container Storage cluster using the object dashboard, see Monitoring OpenShift Container Storage.

3.3.4. Verifying that the storage classes are created and listed

  • Click Storage → Storage Classes from the left pane of the OpenShift Web Console.
  • Verify that the following storage classes are created with the OpenShift Container Storage cluster creation:

    • ocs-external-storagecluster-ceph-rbd
    • ocs-external-storagecluster-ceph-rgw
    • ocs-external-storagecluster-cephfs
    • openshift-storage.noobaa.io
Note
  • If an MDS is not deployed in the external cluster, ocs-external-storagecluster-cephfs storage class will not be created.
  • If an RGW is not deployed in the external cluster, the ocs-external-storagecluster-ceph-rgw storage class will not be created.

For more information regarding MDS and RGW, see Red Hat Ceph Storage documentation

3.3.5. Verifying that Ceph cluster is connected

Run the following command to verify if the OpenShift Container Storage cluster is connected to the external Red Hat Ceph Storage cluster.

$ oc get cephcluster -n openshift-storage
NAME                                      DATADIRHOSTPATH     MONCOUNT    AGE      PHASE       MESSAGE                         HEALTH
ocs-external-storagecluster-cephcluster                                   31m15s   Connected   Cluster connected successfully  HEALTH_OK

3.3.6. Verifying that storage cluster is ready

Run the following command to verify if the storage cluster is ready and the External option is set to true.

$ oc get storagecluster -n openshift-storage
NAME                        AGE      PHASE EXTERNAL  CREATED AT              VERSION
ocs-external-storagecluster 31m15s   Ready true      2021-02-29T20:43:04Z    4.8.0

3.4. Uninstalling OpenShift Container Storage in external mode

3.4.1. Uninstalling OpenShift Container Storage in External mode

Use the steps in this section to uninstall OpenShift Container Storage. Uninstalling OpenShift Container Storage does not remove the RBD pool from the external cluster, or uninstall the external Red Hat Ceph Storage cluster.

Uninstall Annotations

Annotations on the Storage Cluster are used to change the behavior of the uninstall process. To define the uninstall behavior, the following two annotations have been introduced in the storage cluster:

  • uninstall.ocs.openshift.io/cleanup-policy: delete
  • uninstall.ocs.openshift.io/mode: graceful
Note

The uninstall.ocs.openshift.io/cleanup-policy is not applicable for external mode.

The below table provides information on the different values that can used with these annotations:

Table 3.2. uninstall.ocs.openshift.io uninstall annotations descriptions

AnnotationValueDefaultBehavior

cleanup-policy

delete

Yes

Rook cleans up the physical drives and the DataDirHostPath

cleanup-policy

retain

No

Rook does not clean up the physical drives and the DataDirHostPath

mode

graceful

Yes

Rook and NooBaa pauses the uninstall process until the PVCs and the OBCs are removed by the administrator/user

mode

forced

No

Rook and NooBaa proceeds with uninstall even if PVCs/OBCs provisioned using Rook and NooBaa exist respectively

You can change the uninstall mode by editing the value of the annotation by using the following commands:

$ oc annotate storagecluster ocs-external-storagecluster uninstall.ocs.openshift.io/mode="forced" --overwrite
storagecluster.ocs.openshift.io/ocs-external-storagecluster annotated

Prerequisites

  • Ensure that the OpenShift Container Storage cluster is in a healthy state. The uninstall process can fail when some of the pods are not terminated successfully due to insufficient resources or nodes. In case the cluster is in an unhealthy state, contact Red Hat Customer Support before uninstalling OpenShift Container Storage.
  • Ensure that applications are not consuming persistent volume claims (PVCs) or object bucket claims (OBCs) using the storage classes provided by OpenShift Container Storage.

Procedure

  1. Delete the volume snapshots that are using OpenShift Container Storage.

    1. List the volume snapshots from all the namespaces

      $ oc get volumesnapshot --all-namespaces
    2. From the output of the previous command, identify and delete the volume snapshots that are using OpenShift Container Storage.

      $ oc delete volumesnapshot <VOLUME-SNAPSHOT-NAME> -n <NAMESPACE>
  2. Delete PVCs and OBCs that are using OpenShift Container Storage.

    In the default uninstall mode (graceful), the uninstaller waits till all the PVCs and OBCs that use OpenShift Container Storage are deleted.

    If you wish to delete the Storage Cluster without deleting the PVCs beforehand, you may set the uninstall mode annotation to "forced" and skip this step. Doing so will result in orphan PVCs and OBCs in the system.

    1. Delete OpenShift Container Platform monitoring stack PVCs using OpenShift Container Storage.

      See Removing monitoring stack from OpenShift Container Storage

    2. Delete OpenShift Container Platform Registry PVCs using OpenShift Container Storage.

      Removing OpenShift Container Platform registry from OpenShift Container Storage

    3. Delete OpenShift Container Platform logging PVCs using OpenShift Container Storage.

      Removing the cluster logging operator from OpenShift Container Storage

    4. Delete other PVCs and OBCs provisioned using OpenShift Container Storage.

      • Given below is a sample script to identify the PVCs and OBCs provisioned using OpenShift Container Storage. The script ignores the PVCs and OBCs that are used internally by Openshift Container Storage.

        #!/bin/bash
        
        RBD_PROVISIONER="openshift-storage.rbd.csi.ceph.com"
        CEPHFS_PROVISIONER="openshift-storage.cephfs.csi.ceph.com"
        NOOBAA_PROVISIONER="openshift-storage.noobaa.io/obc"
        RGW_PROVISIONER="openshift-storage.ceph.rook.io/bucket"
        
        NOOBAA_DB_PVC="noobaa-db"
        NOOBAA_BACKINGSTORE_PVC="noobaa-default-backing-store-noobaa-pvc"
        
        # Find all the OCS StorageClasses
        OCS_STORAGECLASSES=$(oc get storageclasses | grep -e "$RBD_PROVISIONER" -e "$CEPHFS_PROVISIONER" -e "$NOOBAA_PROVISIONER" -e "$RGW_PROVISIONER" | awk '{print $1}')
        
        # List PVCs in each of the StorageClasses
        for SC in $OCS_STORAGECLASSES
        do
                echo "======================================================================"
                echo "$SC StorageClass PVCs and OBCs"
                echo "======================================================================"
                oc get pvc  --all-namespaces --no-headers 2>/dev/null | grep $SC | grep -v -e "$NOOBAA_DB_PVC" -e "$NOOBAA_BACKINGSTORE_PVC"
                oc get obc  --all-namespaces --no-headers 2>/dev/null | grep $SC
                echo
        done
      • Delete the OBCs.

        $ oc delete obc <obc name> -n <project name>
      • Delete the PVCs.

        $ oc delete pvc <pvc name> -n <project-name>

        Ensure that you have removed any custom backing stores, bucket classes, etc., created in the cluster.

  3. Delete the Storage Cluster object and wait for the removal of the associated resources.

    $ oc delete -n openshift-storage storagecluster --all --wait=true
  4. Delete the namespace and wait until the deletion is complete. You will need to switch to another project if openshift-storage is the active project.

    For example:

    $ oc project default
    $ oc delete project openshift-storage --wait=true --timeout=5m

    The project is deleted if the following command returns a NotFound error.

    $ oc get project openshift-storage
    Note

    While uninstalling OpenShift Container Storage, if the namespace is not deleted completely and remains in Terminating state, perform the steps in Troubleshooting and deleting remaining resources during Uninstall to identify objects that are blocking the namespace from being terminated.

  5. Confirm all PVs provisioned using OpenShift Container Storage are deleted. If there is any PV left in the Released state, delete it.

    $ oc get pv
    $ oc delete pv <pv name>
  6. Delete the Multicloud Object Gateway storageclass.

    $ oc delete storageclass openshift-storage.noobaa.io --wait=true --timeout=5m
  7. Remove CustomResourceDefinitions.

    $ oc delete crd backingstores.noobaa.io bucketclasses.noobaa.io cephblockpools.ceph.rook.io cephclusters.ceph.rook.io cephfilesystems.ceph.rook.io cephnfses.ceph.rook.io cephobjectstores.ceph.rook.io cephobjectstoreusers.ceph.rook.io noobaas.noobaa.io ocsinitializations.ocs.openshift.io storageclusters.ocs.openshift.io cephclients.ceph.rook.io cephobjectrealms.ceph.rook.io cephobjectzonegroups.ceph.rook.io cephobjectzones.ceph.rook.io cephrbdmirrors.ceph.rook.io --wait=true --timeout=5m
  8. To ensure that OpenShift Container Storage is uninstalled completely, on the OpenShift Container Platform Web Console,

    1. Click Storage.
    2. Verify that Overview no longer appears under Storage.

3.4.2. Removing monitoring stack from OpenShift Container Storage

Use this section to clean up the monitoring stack from the OpenShift Container Storage.

The PVCs that are created as a part of configuring the monitoring stack are in the openshift-monitoring namespace.

Prerequisites

Procedure

  1. List the pods and PVCs that are currently running in the openshift-monitoring namespace.

    $ oc get pod,pvc -n openshift-monitoring
    NAME                           READY   STATUS    RESTARTS   AGE
    pod/alertmanager-main-0         3/3     Running   0          8d
    pod/alertmanager-main-1         3/3     Running   0          8d
    pod/alertmanager-main-2         3/3     Running   0          8d
    pod/cluster-monitoring-
    operator-84457656d-pkrxm        1/1     Running   0          8d
    pod/grafana-79ccf6689f-2ll28    2/2     Running   0          8d
    pod/kube-state-metrics-
    7d86fb966-rvd9w                 3/3     Running   0          8d
    pod/node-exporter-25894         2/2     Running   0          8d
    pod/node-exporter-4dsd7         2/2     Running   0          8d
    pod/node-exporter-6p4zc         2/2     Running   0          8d
    pod/node-exporter-jbjvg         2/2     Running   0          8d
    pod/node-exporter-jj4t5         2/2     Running   0          6d18h
    pod/node-exporter-k856s         2/2     Running   0          6d18h
    pod/node-exporter-rf8gn         2/2     Running   0          8d
    pod/node-exporter-rmb5m         2/2     Running   0          6d18h
    pod/node-exporter-zj7kx         2/2     Running   0          8d
    pod/openshift-state-metrics-
    59dbd4f654-4clng                3/3     Running   0          8d
    pod/prometheus-adapter-
    5df5865596-k8dzn                1/1     Running   0          7d23h
    pod/prometheus-adapter-
    5df5865596-n2gj9                1/1     Running   0          7d23h
    pod/prometheus-k8s-0            6/6     Running   1          8d
    pod/prometheus-k8s-1            6/6     Running   1          8d
    pod/prometheus-operator-
    55cfb858c9-c4zd9                1/1     Running   0          6d21h
    pod/telemeter-client-
    78fc8fc97d-2rgfp                3/3     Running   0          8d
    
    NAME                                                              STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS                  AGE
    persistentvolumeclaim/my-alertmanager-claim-alertmanager-main-0   Bound    pvc-0d519c4f-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   8d
    persistentvolumeclaim/my-alertmanager-claim-alertmanager-main-1   Bound    pvc-0d5a9825-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   8d
    persistentvolumeclaim/my-alertmanager-claim-alertmanager-main-2   Bound    pvc-0d6413dc-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   8d
    persistentvolumeclaim/my-prometheus-claim-prometheus-k8s-0        Bound    pvc-0b7c19b0-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   8d
    persistentvolumeclaim/my-prometheus-claim-prometheus-k8s-1        Bound    pvc-0b8aed3f-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   8d
  2. Edit the monitoring configmap.

    $ oc -n openshift-monitoring edit configmap cluster-monitoring-config
  3. Remove any config sections that reference the OpenShift Container Storage storage classes as shown in the following example and save it.

    Before editing

    .
    .
    .
    apiVersion: v1
    data:
      config.yaml: |
        alertmanagerMain:
          volumeClaimTemplate:
            metadata:
              name: my-alertmanager-claim
            spec:
              resources:
                requests:
                  storage: 40Gi
              storageClassName: ocs-external-storagecluster-ceph-rbd
        prometheusK8s:
          volumeClaimTemplate:
            metadata:
              name: my-prometheus-claim
            spec:
              resources:
                requests:
                  storage: 40Gi
              storageClassName: ocs-external-storagecluster-ceph-rbd
    kind: ConfigMap
    metadata:
      creationTimestamp: "2019-12-02T07:47:29Z"
      name: cluster-monitoring-config
      namespace: openshift-monitoring
      resourceVersion: "22110"
      selfLink: /api/v1/namespaces/openshift-monitoring/configmaps/cluster-monitoring-config
      uid: fd6d988b-14d7-11ea-84ff-066035b9efa8
    
    
    .
    .
    .

    After editing

    .
    .
    .
    apiVersion: v1
    data:
      config.yaml: |
    kind: ConfigMap
    metadata:
      creationTimestamp: "2019-11-21T13:07:05Z"
      name: cluster-monitoring-config
      namespace: openshift-monitoring
      resourceVersion: "404352"
      selfLink: /api/v1/namespaces/openshift-monitoring/configmaps/cluster-monitoring-config
      uid: d12c796a-0c5f-11ea-9832-063cd735b81c
    .
    .
    .

    In this example, alertmanagerMain and prometheusK8s monitoring components are using the OpenShift Container Storage PVCs.

  4. List the pods consuming the PVC.

    In this example, the alertmanagerMain and prometheusK8s pods that were consuming the PVCs are in the Terminating state. You can delete the PVCs once these pods are no longer using OpenShift Container Storage PVC.

    $ oc get pod,pvc -n openshift-monitoring
    NAME                                               READY   STATUS      RESTARTS AGE
    pod/alertmanager-main-0                            3/3     Terminating   0      10h
    pod/alertmanager-main-1                            3/3     Terminating   0      10h
    pod/alertmanager-main-2                            3/3     Terminating   0      10h
    pod/cluster-monitoring-operator-84cd9df668-zhjfn   1/1     Running       0      18h
    pod/grafana-5db6fd97f8-pmtbf                       2/2     Running       0      10h
    pod/kube-state-metrics-895899678-z2r9q             3/3     Running       0      10h
    pod/node-exporter-4njxv                            2/2     Running       0      18h
    pod/node-exporter-b8ckz                            2/2     Running       0      11h
    pod/node-exporter-c2vp5                            2/2     Running       0      18h
    pod/node-exporter-cq65n                            2/2     Running       0      18h
    pod/node-exporter-f5sm7                            2/2     Running       0      11h
    pod/node-exporter-f852c                            2/2     Running       0      18h
    pod/node-exporter-l9zn7                            2/2     Running       0      11h
    pod/node-exporter-ngbs8                            2/2     Running       0      18h
    pod/node-exporter-rv4v9                            2/2     Running       0      18h
    pod/openshift-state-metrics-77d5f699d8-69q5x       3/3     Running       0      10h
    pod/prometheus-adapter-765465b56-4tbxx             1/1     Running       0      10h
    pod/prometheus-adapter-765465b56-s2qg2             1/1     Running       0      10h
    pod/prometheus-k8s-0                               6/6     Terminating   1      9m47s
    pod/prometheus-k8s-1                               6/6     Terminating   1      9m47s
    pod/prometheus-operator-cbfd89f9-ldnwc             1/1     Running       0      43m
    pod/telemeter-client-7b5ddb4489-2xfpz              3/3     Running       0      10h
    
    NAME                                                      STATUS  VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS                  AGE
    persistentvolumeclaim/ocs-alertmanager-claim-alertmanager-main-0   Bound    pvc-2eb79797-1fed-11ea-93e1-0a88476a6a64   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   19h
    persistentvolumeclaim/ocs-alertmanager-claim-alertmanager-main-1   Bound    pvc-2ebeee54-1fed-11ea-93e1-0a88476a6a64   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   19h
    persistentvolumeclaim/ocs-alertmanager-claim-alertmanager-main-2   Bound    pvc-2ec6a9cf-1fed-11ea-93e1-0a88476a6a64   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   19h
    persistentvolumeclaim/ocs-prometheus-claim-prometheus-k8s-0        Bound    pvc-3162a80c-1fed-11ea-93e1-0a88476a6a64   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   19h
    persistentvolumeclaim/ocs-prometheus-claim-prometheus-k8s-1        Bound    pvc-316e99e2-1fed-11ea-93e1-0a88476a6a64   40Gi       RWO            ocs-external-storagecluster-ceph-rbd   19h
  5. Delete relevant PVCs. Make sure you delete all the PVCs that are consuming the storage classes.

    $ oc delete -n openshift-monitoring pvc <pvc-name> --wait=true --timeout=5m

3.4.3. Removing OpenShift Container Platform registry from OpenShift Container Storage

Use this section to clean up OpenShift Container Platform registry from OpenShift Container Storage. If you want to configure an alternative storage, see image registry

The PVCs that are created as a part of configuring OpenShift Container Platform registry are in the openshift-image-registry namespace.

Prerequisites

  • The image registry should have been configured to use an OpenShift Container Storage PVC.

Procedure

  1. Edit the configs.imageregistry.operator.openshift.io object and remove the content in the storage section.

    $ oc edit configs.imageregistry.operator.openshift.io

    Before editing

    .
    .
    .
    storage:
      pvc:
        claim: registry-cephfs-rwx-pvc
    .
    .
    .

    After editing

    .
    .
    .
    storage:
      emptyDir: {}
    .
    .
    .

    In this example, the PVC is called registry-cephfs-rwx-pvc, which is now safe to delete.

  2. Delete the PVC.

    $ oc delete pvc <pvc-name> -n openshift-image-registry --wait=true --timeout=5m

3.4.4. Removing the cluster logging operator from OpenShift Container Storage

To clean the cluster logging operator from the OpenShift Container Storage, follow the steps in the procedure.

The PVCs created as a part of configuring cluster logging operator are in the openshift-logging namespace.

Prerequisites

  • The cluster logging instance must be configured to use OpenShift Container Storage PVCs.

Procedure

  1. Remove the ClusterLogging instance in the namespace.

    $ oc delete clusterlogging instance -n openshift-logging --wait=true --timeout=5m

    The PVCs in the openshift-logging namespace are now safe to delete.

  2. Delete PVCs.

    $ oc delete pvc <pvc-name> -n openshift-logging --wait=true --timeout=5m