Chapter 16. Replacing storage devices 16.1. Replacing operational or failed storage devices on Red Hat OpenStack Platform installer-provisioned infrastructure Use this procedure to replace storage device in OpenShift Data Foundation which is deployed on Red Hat OpenStack Platform. This procedure helps to create a new Persistent Volume Claim (PVC) on a new volume and remove the old object storage device (OSD). Procedure Identify the OSD that needs to be replaced and the OpenShift Container Platform node that has the OSD scheduled on it. Example output: In this example, rook-ceph-osd-0-6d77d6c7c6-m8xj6 needs to be replaced and compute-2 is the OpenShift Container platform node on which the OSD is scheduled. Note If the OSD to be replaced is healthy, the status of the pod will be Running . Scale down the OSD deployment for the OSD to be replaced. where, osd_id_to_remove is the integer in the pod name immediately after the rook-ceph-osd prefix. In this example, the deployment name is rook-ceph-osd-0 . Example output: Verify that the rook-ceph-osd pod is terminated. Example output: Note If the rook-ceph-osd pod is in terminating state, use the force option to delete the pod. Example output: Incase, the persistent volume associated with the failed OSD fails, get the failed persistent volumes details and delete them using the following commands: Remove the old OSD from the cluster so that a new OSD can be added. Delete any old ocs-osd-removal jobs. Example output: Change to the openshift-storage project. Remove the old OSD from the cluster. You can add comma separated OSD IDs in the command to remove more than one OSD. (For example, FAILED_OSD_IDS=0,1,2). The FORCE_OSD_REMOVAL value must be changed to "true" in clusters that only have three OSDs, or clusters with insufficient space to restore all three replicas of the data after the OSD is removed. Warning This step results in OSD being completely removed from the cluster. Ensure that the correct value of osd_id_to_remove is provided. Verify that the OSD was removed successfully by checking the status of the ocs-osd-removal-job pod. A status of Completed confirms that the OSD removal job succeeded. Ensure that the OSD removal is completed. Example output: Important If the ocs-osd-removal-job fails and the pod is not in the expected Completed state, check the pod logs for further debugging. For example: If encryption was enabled at the time of install, remove dm-crypt managed device-mapper mapping from the OSD devices that are removed from the respective OpenShift Data Foundation nodes. Get PVC name(s) of the replaced OSD(s) from the logs of ocs-osd-removal-job pod : For example: For each of the nodes identified in step #1, do the following: Create a debug pod and chroot to the host on the storage node. Find relevant device name based on the PVC names identified in the step Remove the mapped device. Note 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 process which was stuck. Terminate the process using kill command. Verify that the device name is removed. Delete the ocs-osd-removal job. Example output: Verfication steps Verify that there is a new OSD running. Example output: Verify that there is a new PVC created which is in Bound state. Example output: Optional: If cluster-wide encryption is enabled on the cluster, verify that the new OSD devices are encrypted. Identify the nodes where the new OSD pods are running. <OSD-pod-name> Is the name of the OSD pod. For example: Example output: For each of the nodes identified in step, do the following: Create a debug pod and open a chroot environment for the selected host(s). Run "lsblk" and check for the "crypt" keyword beside the ocs-deviceset name(s) Log in to OpenShift Web Console and view the storage dashboard. Figure 16.1. OSD status in OpenShift Container Platform storage dashboard after device replacement

Commands:
oc get -n openshift-storage pods -l app=rook-ceph-osd -o wide
rook-ceph-osd-0-6d77d6c7c6-m8xj6 0/1 CrashLoopBackOff 0 24h 10.129.0.16 compute-2 <none> <none> rook-ceph-osd-1-85d99fb95f-2svc7 1/1 Running 0 24h 10.128.2.24 compute-0 <none> <none> rook-ceph-osd-2-6c66cdb977-jp542 1/1 Running 0 24h 10.130.0.18 compute-1 <none> <none>
osd_id_to_remove=0 oc scale -n openshift-storage deployment rook-ceph-osd-USD{osd_id_to_remove} --replicas=0
deployment.extensions/rook-ceph-osd-0 scaled
oc get -n openshift-storage pods -l ceph-osd-id=USD{osd_id_to_remove}
No resources found.
oc delete pod rook-ceph-osd-0-6d77d6c7c6-m8xj6 --force --grace-period=0
warning: Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely. pod "rook-ceph-osd-0-6d77d6c7c6-m8xj6" force deleted
oc get pv oc delete pv <failed-pv-name>
oc delete -n openshift-storage job ocs-osd-removal-USD{osd_id_to_remove}
job.batch "ocs-osd-removal-0" deleted
oc project openshift-storage
oc process -n openshift-storage ocs-osd-removal -p FAILED_OSD_IDS=USD{osd_id_to_remove} -p FORCE_OSD_REMOVAL=false |oc create -n openshift-storage -f -
oc get pod -l job-name=ocs-osd-removal-job -n openshift-storage
oc logs -l job-name=ocs-osd-removal-job -n openshift-storage --tail=-1 | egrep -i 'completed removal'
2022-05-10 06:50:04.501511 I | cephosd: completed removal of OSD 0
oc logs -l job-name=ocs-osd-removal-job -n openshift-storage --tail=-1
oc logs -l job-name=ocs-osd-removal-job -n openshift-storage --tail=-1 |egrep -i 'pvc|deviceset'
2021-05-12 14:31:34.666000 I | cephosd: removing the OSD PVC "ocs-deviceset-xxxx-xxx-xxx-xxx"
oc debug node/<node name> chroot /host
sh-4.4# dmsetup ls| grep <pvc name> ocs-deviceset-xxx-xxx-xxx-xxx-block-dmcrypt (253:0)
cryptsetup luksClose --debug --verbose ocs-deviceset-xxx-xxx-xxx-xxx-block-dmcrypt
ps -ef | grep crypt
kill -9 <PID>
dmsetup ls
oc delete -n openshift-storage job ocs-osd-removal-USD{osd_id_to_remove}
job.batch "ocs-osd-removal-0" deleted
oc get -n openshift-storage pods -l app=rook-ceph-osd
rook-ceph-osd-0-5f7f4747d4-snshw 1/1 Running 0 4m47s rook-ceph-osd-1-85d99fb95f-2svc7 1/1 Running 0 1d20h rook-ceph-osd-2-6c66cdb977-jp542 1/1 Running 0 1d20h
oc get -n openshift-storage pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE db-noobaa-db-0 Bound pvc-b44ebb5e-3c67-4000-998e-304752deb5a7 50Gi RWO ocs-storagecluster-ceph-rbd 6d ocs-deviceset-0-data-0-gwb5l Bound pvc-bea680cd-7278-463d-a4f6-3eb5d3d0defe 512Gi RWO standard 94s ocs-deviceset-1-data-0-w9pjm Bound pvc-01aded83-6ef1-42d1-a32e-6ca0964b96d4 512Gi RWO standard 6d ocs-deviceset-2-data-0-7bxcq Bound pvc-5d07cd6c-23cb-468c-89c1-72d07040e308 512Gi RWO standard 6d
oc get -n openshift-storage -o=custom-columns=NODE:.spec.nodeName pod/_<OSD-pod-name>_
oc get -n openshift-storage -o=custom-columns=NODE:.spec.nodeName pod/rook-ceph-osd-0-544db49d7f-qrgqm
NODE compute-1
oc debug node/<node name> chroot /host
lsblk