Chapter 3. Uninstalling OpenShift Container Storage

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

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   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>

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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 Section 3.2, “Removing monitoring stack from OpenShift Container Storage”

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

      See Section 3.3, “Removing OpenShift Container Platform registry from OpenShift Container Storage”

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

      See Section 3.4, “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 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

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        Note

        Omit RGW_PROVISIONER for cloud platforms.

      • Delete the OBCs.

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

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      • Delete the PVCs.

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

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        Note

        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

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4. Check for cleanup pods if the uninstall.ocs.openshift.io/cleanup-policy was set to delete(default) and ensure that their status is Completed.

   $ oc get pods -n openshift-storage | grep -i cleanup
   NAME                                READY   STATUS      RESTARTS   AGE
   cluster-cleanup-job-<xx>        	0/1     Completed   0          8m35s
   cluster-cleanup-job-<yy>     		0/1     Completed   0          8m35s
   cluster-cleanup-job-<zz>     		0/1     Completed   0          8m35s

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5. Confirm that the directory /var/lib/rook is now empty. This directory will be empty only if the uninstall.ocs.openshift.io/cleanup-policy annotation was set to delete(default).

   $ for i in $(oc get node -l cluster.ocs.openshift.io/openshift-storage= -o jsonpath='{ .items[*].metadata.name }'); do oc debug node/${i} -- chroot /host  ls -l /var/lib/rook; done

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6. If encryption was enabled at the time of install, remove dm-crypt managed device-mapper mapping from OSD devices on all the OpenShift Container Storage nodes.

   1. Create a debug pod and chroot to the host on the storage node.

      $ oc debug node/<node name>
      $ chroot /host

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   2. Get Device names and make note of the OpenShift Container Storage devices.

      $ dmsetup ls
      ocs-deviceset-0-data-0-57snx-block-dmcrypt (253:1)

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   3. Remove the mapped device.

      $ cryptsetup luksClose --debug --verbose ocs-deviceset-0-data-0-57snx-block-dmcrypt

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      If the above command gets stuck due to insufficient privileges, run the following commands:

      • Press CTRL+Z to exit the above command.

      • Find PID of the cryptsetup process which was stuck.

        $ ps

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        Example output:

        PID     TTY    TIME     CMD
        778825   ?     00:00:00 cryptsetup

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        Take a note of the PID number to kill. In this example, PID is 778825.

      • Terminate the process using kill command.

        $ kill -9 <PID>

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      • Verify that the device name is removed.

        $ dmsetup ls

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7. Delete the namespace and wait till 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

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

   $ oc get project openshift-storage

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   Note

   While uninstalling OpenShift Container Storage, if 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.

8. Unlabel the storage nodes.

   $ oc label nodes  --all cluster.ocs.openshift.io/openshift-storage-
   $ oc label nodes  --all topology.rook.io/rack-

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9. Remove the OpenShift Container Storage taint if the nodes were tainted.

   $ oc adm taint nodes --all node.ocs.openshift.io/storage-

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10. 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>

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11. Delete the Multicloud Object Gateway storageclass.

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

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12. 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

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13. To ensure that OpenShift Container Storage is uninstalled completely, on the OpenShift Container Platform Web Console,

    1. Click Home Overview to access the dashboard.
    2. Verify that the Persistent Storage and Object Service tabs no longer appear next to the Cluster tab.

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-storagecluster-ceph-rbd   8d
   persistentvolumeclaim/my-alertmanager-claim-alertmanager-main-1   Bound    pvc-0d5a9825-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-storagecluster-ceph-rbd   8d
   persistentvolumeclaim/my-alertmanager-claim-alertmanager-main-2   Bound    pvc-0d6413dc-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-storagecluster-ceph-rbd   8d
   persistentvolumeclaim/my-prometheus-claim-prometheus-k8s-0        Bound    pvc-0b7c19b0-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-storagecluster-ceph-rbd   8d
   persistentvolumeclaim/my-prometheus-claim-prometheus-k8s-1        Bound    pvc-0b8aed3f-15a5-11ea-baa0-026d231574aa   40Gi       RWO            ocs-storagecluster-ceph-rbd   8d

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2. Edit the monitoring configmap.

   $ oc -n openshift-monitoring edit configmap cluster-monitoring-config

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3. Remove any config sections that reference the OpenShift Container Storage storage classes as shown in the following example and save it.

   Before editing

   Expand

   . . . apiVersion: v1 data: config.yaml: | alertmanagerMain: volumeClaimTemplate: metadata: name: my-alertmanager-claim spec: resources: requests: storage: 40Gi storageClassName: ocs-storagecluster-ceph-rbd prometheusK8s: volumeClaimTemplate: metadata: name: my-prometheus-claim spec: resources: requests: storage: 40Gi storageClassName: ocs-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 . . . Copy to Clipboard Toggle word wrap

   Show more

   After editing

   Expand

   . . . 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 . . . Copy to Clipboard Toggle word wrap

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

4. 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

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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

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   Before editing

   . . . storage: pvc: claim: registry-cephfs-rwx-pvc . . . Copy to Clipboard Toggle word wrap

   After editing

   . . . storage: . . . Copy to Clipboard Toggle word wrap

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   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

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Procedure

1. Remove the ClusterLogging instance in the namespace.

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

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   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

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