Chapter 13. Replacing storage nodes

Procedure

1. Log in to OpenShift Web Console and click Compute Nodes.
2. Identify the node that needs to be replaced. Take a note of its Machine Name.

3. Get labels on the node to be replaced.

   $ oc get nodes --show-labels | grep <node_name>

4. Identify the mon (if any) and OSDs that are running in the node to be replaced.

   $ oc get pods -n openshift-storage -o wide | grep -i <node_name>

5. Scale down the deployments of the pods identified in the previous step.

   For example:

   $ oc scale deployment rook-ceph-mon-c --replicas=0 -n openshift-storage
   $ oc scale deployment rook-ceph-osd-0 --replicas=0 -n openshift-storage
   $ oc scale deployment --selector=app=rook-ceph-crashcollector,node_name=<node_name>  --replicas=0 -n openshift-storage

6. Mark the nodes as unschedulable.

   $ oc adm cordon <node_name>

7. Drain the node.

   $ oc adm drain <node_name> --force --delete-local-data --ignore-daemonsets

8. Click Compute Machines. Search for the required machine.
9. Besides the required machine, click the Action menu (⋮) Delete Machine.
10. Click Delete to confirm the machine deletion. A new machine is automatically created.

11. Wait for the new machine to start and transition into Running state.

    Important

    This activity may take at least 5-10 minutes or more.

12. Click Compute Nodes in the OpenShift web console. Confirm if the new node is in Ready state.

13. Apply the OpenShift Container Storage label to the new node using any one of the following:

    From User interface

    1. For the new node, click Action Menu (⋮) Edit Labels.
    2. Add cluster.ocs.openshift.io/openshift-storage and click Save.

    From Command line interface

    • Execute the following command to apply the OpenShift Container Storage label to the new node:

    $ oc label node <new_node_name> cluster.ocs.openshift.io/openshift-storage=""

14. Add the local storage devices available on these worker nodes to the OpenShift Container Storage StorageCluster.

    1. Determine which localVolumeSet to edit.

       Replace local-storage-project in the following commands with the name of your local storage project. The default project name is openshift-local-storage in OpenShift Container Storage 4.6 and later. Previous versions use local-storage by default.

       # oc get -n local-storage-project localvolumeset
       NAME          AGE
       localblock   25h

    2. Add the new node to the localVolumeSet definition.

       # oc edit -n local-storage-project localvolumeset localblock
       [...]
          nodeSelector:
           nodeSelectorTerms:
             - matchExpressions:
                 - key: kubernetes.io/hostname
                   operator: In
                   values:
                   - server1.example.com
                   - server2.example.com
                #  - server3.example.com
                   - newnode.example.com
       [...]

       Remember to save before exiting the editor.

15. Verify that the new localblock PV is available.

    $ oc get pv | grep localblock
              CAPA- ACCESS RECLAIM                                STORAGE
    NAME      CITY  MODES  POLICY  STATUS     CLAIM               CLASS       AGE
    local-pv- 931Gi  RWO   Delete  Bound      openshift-storage/  localblock  25h
    3e8964d3                                  ocs-deviceset-2-0
                                              -79j94
    local-pv- 931Gi  RWO   Delete  Bound      openshift-storage/  localblock  25h
    414755e0                                  ocs-deviceset-1-0
                                              -959rp
    local-pv- 931Gi RWO Delete Available localblock 3m24s b481410
    local-pv- 931Gi  RWO   Delete  Bound      openshift-storage/  localblock  25h
    d9c5cbd6                                  ocs-deviceset-0-0
                                              -nvs68

16. Change to the openshift-storage project.

    $ oc project openshift-storage

17. Remove the failed OSD from the cluster.

    $ oc process -n openshift-storage ocs-osd-removal \
    -p FAILED_OSD_IDS=failed-osd-id1,failed-osd-id2 | oc create -f -

18. Verify that the OSD was removed successfully by checking the status of the ocs-osd-removal pod.

    A status of Completed confirms that the OSD removal job succeeded.

    # oc get pod -l job-name=ocs-osd-removal-failed-osd-id -n openshift-storage

    Note

    If ocs-osd-removal fails and the pod is not in the expected Completed state, check the pod logs for further debugging. For example:

    # oc logs -l job-name=ocs-osd-removal-failed-osd_id -n openshift-storage --tail=-1

19. Delete the PV associated with the failed node.

    1. Identify the PV associated with the PVC.

       # oc get -n openshift-storage pvc claim-name

       For example:

       # oc get -n openshift-storage pvc ocs-deviceset-0-0-nvs68
                                                   ACCESS STORAGE
       NAME           STATUS    VOLUME    CAPACITY MODES  CLASS      AGE
       ocs-deviceset- Released  local-pv- 931Gi    RWO    localblock 24h
       0-0-nvs68                d9c5cbd6

    2. Delete the PV.

       # oc delete pv <persistent-volume>

       For example:

       # oc delete pv local-pv-d9c5cbd6
       persistentvolume "local-pv-d9c5cbd6" deleted

20. Delete the crashcollector pod deployment.

    $ oc delete deployment --selector=app=rook-ceph-crashcollector,node_name=failed-node-name -n openshift-storage

21. Deploy the new OSD by restarting the rook-ceph-operator to force operator reconciliation.

    # oc get -n openshift-storage pod -l app=rook-ceph-operator

    Example output:

    NAME                                  READY   STATUS    RESTARTS   AGE
    rook-ceph-operator-6f74fb5bff-2d982   1/1     Running   0          1d20h

    1. Delete the rook-ceph-operator.

       # oc delete -n openshift-storage pod rook-ceph-operator-6f74fb5bff-2d982

       Example output:

       pod "rook-ceph-operator-6f74fb5bff-2d982" deleted

    2. Verify that the rook-ceph-operator pod is restarted.

       # oc get -n openshift-storage pod -l app=rook-ceph-operator

       Example output:

       NAME                                  READY   STATUS    RESTARTS   AGE
       rook-ceph-operator-6f74fb5bff-7mvrq   1/1     Running   0          66s

       Creation of the new OSD and mon might take several minutes after the operator restarts.

22. Delete the ocs-osd-removal job.

    # oc delete job ocs-osd-removal-${osd_id_to_remove}

    Example output:

    job.batch "ocs-osd-removal-0" deleted

Verification steps

1. Execute the following command and verify that the new node is present in the output:

   $ oc get nodes --show-labels | grep cluster.ocs.openshift.io/openshift-storage= |cut -d' ' -f1

2. Click Workloads Pods, confirm that at least the following pods on the new node are in Running state:

   • csi-cephfsplugin-*
   • csi-rbdplugin-*

3. Verify that all other required OpenShift Container Storage pods are in Running state.

   Ensure that the new incremental mon is created and is in the Running state.

   $ oc get pod -n openshift-storage | grep mon

   Example output:

   rook-ceph-mon-c-64556f7659-c2ngc                                  1/1     Running     0          6h14m
   rook-ceph-mon-d-7c8b74dc4d-tt6hd                                  1/1     Running     0          4h24m
   rook-ceph-mon-e-57fb8c657-wg5f2                                   1/1     Running     0          162m

   OSD and Mon might take several minutes to get to the Running state.

4. Verify that new OSD pods are running on the replacement node.

   $ oc get pods -o wide -n openshift-storage| egrep -i new-node-name | egrep osd

5. (Optional) If data encryption is enabled on the cluster, verify that the new OSD devices are encrypted.

   For each of the new nodes identified in previous step, do the following:

   1. Create a debug pod and open a chroot environment for the selected host(s).

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

   2. Run “lsblk” and check for the “crypt” keyword beside the ocs-deviceset name(s)

      $ lsblk

6. If verification steps fail, contact Red Hat Support.

Procedure

1. Log in to OpenShift Web Console and click Compute Nodes.
2. Identify the node that needs to be replaced. Take a note of its Machine Name.

3. Get the labels on the node to be replaced.

   $ oc get nodes --show-labels | grep <node_name>

4. Identify the mon (if any) and OSDs that are running in the node to be replaced.

   $ oc get pods -n openshift-storage -o wide | grep -i <node_name>

5. Scale down the deployments of the pods identified in the previous step.

   For example:

   $ oc scale deployment rook-ceph-mon-c --replicas=0 -n openshift-storage
   $ oc scale deployment rook-ceph-osd-0 --replicas=0 -n openshift-storage
   $ oc scale deployment --selector=app=rook-ceph-crashcollector,node_name=<node_name>  --replicas=0 -n openshift-storage

6. Mark the node as unschedulable.

   $ oc adm cordon <node_name>

7. Remove the pods which are in Terminating state.

   $ oc get pods -A -o wide | grep -i <node_name> |  awk '{if ($4 == "Terminating") system ("oc -n " $1 " delete pods " $2  " --grace-period=0 " " --force ")}'

8. Drain the node.

   $ oc adm drain <node_name> --force --delete-local-data --ignore-daemonsets

9. Click Compute Machines. Search for the required machine.
10. Besides the required machine, click the Action menu (⋮) Delete Machine.
11. Click Delete to confirm the machine deletion. A new machine is automatically created.

12. Wait for the new machine to start and transition into Running state.

    Important

    This activity may take at least 5-10 minutes or more.

13. Click Compute Nodes in the OpenShift web console. Confirm if the new node is in Ready state.

14. Apply the OpenShift Container Storage label to the new node using any one of the following:

    From User interface

    1. For the new node, click Action Menu (⋮) Edit Labels.
    2. Add cluster.ocs.openshift.io/openshift-storage and click Save.

    From Command line interface

    • Execute the following command to apply the OpenShift Container Storage label to the new node:

    $ oc label node <new_node_name> cluster.ocs.openshift.io/openshift-storage=""

15. Add the local storage devices available in the new worker node to the OpenShift Container Storage StorageCluster.

16. Add the local storage devices available on these worker nodes to the OpenShift Container Storage StorageCluster.

    1. Determine which localVolumeSet to edit.

       Replace local-storage-project in the following commands with the name of your local storage project. The default project name is openshift-local-storage in OpenShift Container Storage 4.6 and later. Previous versions use local-storage by default.

       # oc get -n local-storage-project localvolumeset
       NAME          AGE
       localblock   25h

    2. Add the new node to the localVolumeSet definition.

       # oc edit -n local-storage-project localvolumeset localblock
       [...]
          nodeSelector:
           nodeSelectorTerms:
             - matchExpressions:
                 - key: kubernetes.io/hostname
                   operator: In
                   values:
                   - server1.example.com
                   - server2.example.com
                #  - server3.example.com
                   - newnode.example.com
       [...]

       Remember to save before exiting the editor.

17. Verify that the new localblock PV is available.

    $ oc get pv | grep localblock
              CAPA- ACCESS RECLAIM                                STORAGE
    NAME      CITY  MODES  POLICY  STATUS     CLAIM               CLASS       AGE
    local-pv- 931Gi  RWO   Delete  Bound      openshift-storage/  localblock  25h
    3e8964d3                                  ocs-deviceset-2-0
                                              -79j94
    local-pv- 931Gi  RWO   Delete  Bound      openshift-storage/  localblock  25h
    414755e0                                  ocs-deviceset-1-0
                                              -959rp
    local-pv- 931Gi RWO Delete Available localblock 3m24s b481410
    local-pv- 931Gi  RWO   Delete  Bound      openshift-storage/  localblock  25h
    d9c5cbd6                                  ocs-deviceset-0-0
                                              -nvs68

18. Change to the openshift-storage project.

    $ oc project openshift-storage

19. Remove the failed OSD from the cluster.

    $ oc process -n openshift-storage ocs-osd-removal \
    -p FAILED_OSD_IDS=failed-osd-id1,failed-osd-id2 | oc create -f -

20. Verify that the OSD was removed successfully by checking the status of the ocs-osd-removal pod.

    A status of Completed confirms that the OSD removal job succeeded.

    # oc get pod -l job-name=ocs-osd-removal-failed-osd-id -n openshift-storage

    Note

    If ocs-osd-removal fails and the pod is not in the expected Completed state, check the pod logs for further debugging. For example:

    # oc logs -l job-name=ocs-osd-removal-failed-osd_id -n openshift-storage --tail=-1

21. Delete the PV associated with the failed node.

    1. Identify the PV associated with the PVC.

       # oc get -n openshift-storage pvc claim-name

       For example:

       # oc get -n openshift-storage pvc ocs-deviceset-0-0-nvs68
                                                   ACCESS STORAGE
       NAME           STATUS    VOLUME    CAPACITY MODES  CLASS      AGE
       ocs-deviceset- Released  local-pv- 931Gi    RWO    localblock 24h
       0-0-nvs68                d9c5cbd6

    2. Delete the PV.

       # oc delete pv <persistent-volume>

       For example:

       # oc delete pv local-pv-d9c5cbd6
       persistentvolume "local-pv-d9c5cbd6" deleted

22. Delete the crashcollector pod deployment.

    $ oc delete deployment --selector=app=rook-ceph-crashcollector,node_name=failed-node-name -n openshift-storage

23. Deploy the new OSD by restarting the rook-ceph-operator to force operator reconciliation.

    # oc get -n openshift-storage pod -l app=rook-ceph-operator

    Example output:

    NAME                                  READY   STATUS    RESTARTS   AGE
    rook-ceph-operator-6f74fb5bff-2d982   1/1     Running   0          1d20h

    1. Delete the rook-ceph-operator.

       # oc delete -n openshift-storage pod rook-ceph-operator-6f74fb5bff-2d982

       Example output:

       pod "rook-ceph-operator-6f74fb5bff-2d982" deleted

    2. Verify that the rook-ceph-operator pod is restarted.

       # oc get -n openshift-storage pod -l app=rook-ceph-operator

       Example output:

       NAME                                  READY   STATUS    RESTARTS   AGE
       rook-ceph-operator-6f74fb5bff-7mvrq   1/1     Running   0          66s

       Creation of the new OSD and mon might take several minutes after the operator restarts.

24. Delete the`ocs-osd-removal` job.

    # oc delete job ocs-osd-removal-${osd_id_to_remove}

    Example output:

    job.batch "ocs-osd-removal-0" deleted

Verification steps

1. Execute the following command and verify that the new node is present in the output:

   $ oc get nodes --show-labels | grep cluster.ocs.openshift.io/openshift-storage= |cut -d' ' -f1

2. Click Workloads Pods, confirm that at least the following pods on the new node are in Running state:

   • csi-cephfsplugin-*
   • csi-rbdplugin-*

3. Verify that all other required OpenShift Container Storage pods are in Running state.

   Ensure that the new incremental mon is created and is in the Running state.

   $ oc get pod -n openshift-storage | grep mon

   Example output:

   rook-ceph-mon-c-64556f7659-c2ngc                                  1/1     Running     0          6h14m
   rook-ceph-mon-d-7c8b74dc4d-tt6hd                                  1/1     Running     0          4h24m
   rook-ceph-mon-e-57fb8c657-wg5f2                                   1/1     Running     0          162m

   OSD and Mon might take several minutes to get to the Running state.

4. Verify that new OSD pods are running on the replacement node.

   $ oc get pods -o wide -n openshift-storage| egrep -i new-node-name | egrep osd

5. (Optional) If data encryption is enabled on the cluster, verify that the new OSD devices are encrypted.

   For each of the new nodes identified in previous step, do the following:

   1. Create a debug pod and open a chroot environment for the selected host(s).

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

   2. Run “lsblk” and check for the “crypt” keyword beside the ocs-deviceset name(s)

      $ lsblk

6. If verification steps fail, contact Red Hat Support.