Chapter 9. Removing failed or unwanted Ceph Object Storage devices The failed or unwanted Ceph OSDs (Object Storage Devices) affects the performance of the storage infrastructure. Hence, to improve the reliability and resilience of the storage cluster, you must remove the failed or unwanted Ceph OSDs. If you have any failed or unwanted Ceph OSDs to remove: Verify the Ceph health status. For more information see: Verifying Ceph cluster is healthy . Based on the provisioning of the OSDs, remove failed or unwanted Ceph OSDs. See: Removing failed or unwanted Ceph OSDs in dynamically provisioned Red Hat OpenShift Data Foundation . Removing failed or unwanted Ceph OSDs provisioned using local storage devices . If you are using local disks, you can reuse these disks after removing the old OSDs. 9.1. Verifying Ceph cluster is healthy Storage health is visible on the Block and File and Object dashboards. Procedure In the OpenShift Web Console, click Storage Data Foundation . In the Status card of the Overview tab, click Storage System and then click the storage system link from the pop up that appears. In the Status card of the Block and File tab, verify that the Storage Cluster has a green tick. In the Details card, verify that the cluster information is displayed. 9.2. Removing failed or unwanted Ceph OSDs in dynamically provisioned Red Hat OpenShift Data Foundation Follow the steps in the procedure to remove the failed or unwanted Ceph Object Storage Devices (OSDs) in dynamically provisioned Red Hat OpenShift Data Foundation. Important Scaling down of clusters is supported only with the help of the Red Hat support team. Warning Removing an OSD when the Ceph component is not in a healthy state can result in data loss. Removing two or more OSDs at the same time results in data loss. Prerequisites Check if Ceph is healthy. For more information see Verifying Ceph cluster is healthy . Ensure no alerts are firing or any rebuilding process is in progress. Procedure Scale down the OSD deployment. Get the osd-prepare pod for the Ceph OSD to be removed. Delete the osd-prepare pod. Remove the failed OSD from the cluster. where, FAILED_OSD_ID is the integer in the pod name immediately after the rook-ceph-osd prefix. Verify that the OSD is removed successfully by checking the logs. Optional: If you get an error as cephosd:osd.0 is NOT ok to destroy from the ocs-osd-removal-job pod in OpenShift Container Platform, see Troubleshooting the error cephosd:osd.0 is NOT ok to destroy while removing failed or unwanted Ceph OSDs . Delete the OSD deployment. Verification step To check if the OSD is deleted successfully, run: This command must return the status as Completed . 9.3. Removing failed or unwanted Ceph OSDs provisioned using local storage devices You can remove failed or unwanted Ceph provisioned Object Storage Devices (OSDs) using local storage devices by following the steps in the procedure. Important Scaling down of clusters is supported only with the help of the Red Hat support team. Warning Removing an OSD when the Ceph component is not in a healthy state can result in data loss. Removing two or more OSDs at the same time results in data loss. Prerequisites Check if Ceph is healthy. For more information see Verifying Ceph cluster is healthy . Ensure no alerts are firing or any rebuilding process is in progress. Procedure Forcibly, mark the OSD down by scaling the replicas on the OSD deployment to 0. You can skip this step if the OSD is already down due to failure. Remove the failed OSD from the cluster. where, FAILED_OSD_ID is the integer in the pod name immediately after the rook-ceph-osd prefix. Verify that the OSD is removed successfully by checking the logs. Optional: If you get an error as cephosd:osd.0 is NOT ok to destroy from the ocs-osd-removal-job pod in OpenShift Container Platform, see Troubleshooting the error cephosd:osd.0 is NOT ok to destroy while removing failed or unwanted Ceph OSDs . Delete persistent volume claim (PVC) resources associated with the failed OSD. Get the PVC associated with the failed OSD. Get the persistent volume (PV) associated with the PVC. Get the failed device name. Get the prepare-pod associated with the failed OSD. Delete the osd-prepare pod before removing the associated PVC. Delete the PVC associated with the failed OSD. Remove failed device entry from the LocalVolume custom resource (CR). Log in to node with the failed device. Record the /dev/disk/by-id/<id> for the failed device name. Optional: In case, Local Storage Operator is used for provisioning OSD, login to the machine with {osd-id} and remove the device symlink. Get the OSD symlink for the failed device name. Remove the symlink. Delete the PV associated with the OSD. Verification step To check if the OSD is deleted successfully, run: This command must return the status as Completed . 9.4. Troubleshooting the error cephosd:osd.0 is NOT ok to destroy while removing failed or unwanted Ceph OSDs If you get an error as cephosd:osd.0 is NOT ok to destroy from the ocs-osd-removal-job pod in OpenShift Container Platform, run the Object Storage Device (OSD) removal job with FORCE_OSD_REMOVAL option to move the OSD to a destroyed state. Note You must use the FORCE_OSD_REMOVAL option only if all the PGs are in active state. If not, PGs must either complete the back filling or further investigate to ensure they are active.

Commands:
oc scale deployment rook-ceph-osd-<osd-id> --replicas=0
oc get deployment rook-ceph-osd-<osd-id> -oyaml | grep ceph.rook.io/pvc
oc delete -n openshift-storage pod rook-ceph-osd-prepare-<pvc-from-above-command>-<pod-suffix>
failed_osd_id=<osd-id> oc process -n openshift-storage ocs-osd-removal -p FAILED_OSD_IDS=USD<failed_osd_id> | oc create -f -
oc logs -n openshift-storage ocs-osd-removal-USD<failed_osd_id>-<pod-suffix>
oc delete deployment rook-ceph-osd-<osd-id>
oc get pod -n openshift-storage ocs-osd-removal-USD<failed_osd_id>-<pod-suffix>
oc scale deployment rook-ceph-osd-<osd-id> --replicas=0
failed_osd_id=<osd_id> oc process -n openshift-storage ocs-osd-removal -p FAILED_OSD_IDS=USD<failed_osd_id> | oc create -f -
oc logs -n openshift-storage ocs-osd-removal-USD<failed_osd_id>-<pod-suffix>
oc get -n openshift-storage -o yaml deployment rook-ceph-osd-<osd-id> | grep ceph.rook.io/pvc
oc get -n openshift-storage pvc <pvc-name>
oc get pv <pv-name-from-above-command> -oyaml | grep path
oc describe -n openshift-storage pvc ocs-deviceset-0-0-nvs68 | grep Mounted
oc delete -n openshift-storage pod <osd-prepare-pod-from-above-command>
oc delete -n openshift-storage pvc <pvc-name-from-step-a>
oc debug node/<node_with_failed_osd>
ls -alh /mnt/local-storage/localblock/
oc debug node/<node_with_failed_osd>
ls -alh /mnt/local-storage/localblock
rm /mnt/local-storage/localblock/<failed-device-name>
oc delete pv <pv-name>
#oc get pod -n openshift-storage ocs-osd-removal-USD<failed_osd_id>-<pod-suffix>
oc process -n openshift-storage ocs-osd-removal -p FORCE_OSD_REMOVAL=true -p FAILED_OSD_IDS=USD<failed_osd_id> | oc create -f -