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Replacing devices

Red Hat OpenShift Container Storage 4.7

Instructions for safely replacing operational or failed devices

Red Hat Storage Documentation Team

Abstract

This document explains how to safely replace storage devices for Red Hat OpenShift Container Storage.

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Preface
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Depending on the type of your deployment, you can choose one of the following procedures to replace a storage device:

Note

OpenShift Container Storage does not support heterogeneous OSD sizes.

When you need to replace a device in a dynamically created storage cluster on an AWS user-provisioned infrastructure, you must replace the storage node. For information about how to replace nodes, see:

When you need to replace a device in a dynamically created storage cluster on an AWS installer-provisioned infrastructure, you must replace the storage node. For information about how to replace nodes, see:

Use this procedure when one or more virtual machine disks (VMDK) needs to be replaced in OpenShift Container Storage which is deployed dynamically on VMware infrastructure. This procedure helps to create a new Persistent Volume Claim (PVC) on a new volume and remove the old object storage device (OSD).

Prerequisites

  • Ensure that the data is resilient.

    • On the OpenShift Web console, navigate to Storage → Overview.
    • Under Persistent Storage in the Status card, confirm that the Data Resiliency has a green tick mark.

Procedure

  1. Identify the OSD that needs to be replaced and the OpenShift Container Platform node that has the OSD scheduled on it. 

    $ oc get -n openshift-storage pods -l app=rook-ceph-osd -o wide
    Copy to Clipboard Toggle word wrap

    Example output: 

    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>
    Copy to Clipboard Toggle word wrap

    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.

  2. Scale down the OSD deployment for the OSD to be replaced.

    Each time you want to replace the OSD, repeat this step by updating the osd_id_to_remove parameter with the OSD ID. 

    $ osd_id_to_remove=0
$ oc scale -n openshift-storage deployment rook-ceph-osd-${osd_id_to_remove} --replicas=0
    Copy to Clipboard Toggle word wrap

    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: 

    deployment.extensions/rook-ceph-osd-0 scaled
    Copy to Clipboard Toggle word wrap

  3. Verify that the rook-ceph-osd pod is terminated. 

    $ oc get -n openshift-storage pods -l ceph-osd-id=${osd_id_to_remove}
    Copy to Clipboard Toggle word wrap

    Example output: 

    No resources found.
    Copy to Clipboard Toggle word wrap
    Note

    If the rook-ceph-osd pod is in terminating state, use the force option to delete the pod. 

    $ oc delete pod rook-ceph-osd-0-6d77d6c7c6-m8xj6 --force --grace-period=0
    Copy to Clipboard Toggle word wrap

    Example output: 

    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
    Copy to Clipboard Toggle word wrap

  4. Remove the old OSD from the cluster so that a new OSD can be added.

    1. Delete any old ocs-osd-removal jobs. 

      $ oc delete -n openshift-storage job ocs-osd-removal-job
      Copy to Clipboard Toggle word wrap

      Example output: 

      job.batch "ocs-osd-removal-job" deleted
      Copy to Clipboard Toggle word wrap

    2. Change to the openshift-storage project. 

      $ oc project openshift-storage
      Copy to Clipboard Toggle word wrap

    3. Remove the old OSD from the cluster. 

      $ oc process -n openshift-storage ocs-osd-removal \
-p FAILED_OSD_IDS=<failed_osd_id> FORCE_OSD_REMOVAL=false | oc create -n openshift-storage -f -
      Copy to Clipboard Toggle word wrap
      <failed_osd_id>

      Is the integer in the pod name immediately after the rook-ceph-osd prefix. 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.

  5. Verify that the OSD is 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-job -n openshift-storage
    Copy to Clipboard Toggle word wrap
    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-job -n openshift-storage --tail=-1'
    Copy to Clipboard Toggle word wrap

  6. 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 Container Storage nodes.

    1. Get PVC name(s) of the replaced OSD(s) from the logs of ocs-osd-removal-job pod : 

      $ oc logs -l job-name=ocs-osd-removal-job -n openshift-storage --tail=-1  |egrep -i ‘pvc|deviceset’
      Copy to Clipboard Toggle word wrap

      For example: 

      2021-05-12 14:31:34.666000 I | cephosd: removing the OSD PVC "ocs-deviceset-xxxx-xxx-xxx-xxx"
      Copy to Clipboard Toggle word wrap

    2. For each of the nodes identified in step #1, do the following:

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

        $ oc debug node/<node name>
$ chroot /host
        Copy to Clipboard Toggle word wrap

      2. Find relevant device name based on the PVC names identified in the previous step 

        sh-4.4# dmsetup ls| grep <pvc name>
ocs-deviceset-xxx-xxx-xxx-xxx-block-dmcrypt (253:0)
        Copy to Clipboard Toggle word wrap

      3. Remove the mapped device. 

        $ cryptsetup luksClose --debug --verbose ocs-deviceset-xxx-xxx-xxx-xxx-block-dmcrypt
        Copy to Clipboard Toggle word wrap
        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. 

          $ ps -ef | grep crypt
          Copy to Clipboard Toggle word wrap

        • Terminate the process using kill command. 

          $ kill -9 <PID>
          Copy to Clipboard Toggle word wrap

        • Verify that the device name is removed. 

          $ dmsetup ls
          Copy to Clipboard Toggle word wrap

  7. Delete the ocs-osd-removal job. 

    $ oc delete -n openshift-storage job ocs-osd-removal-job
    Copy to Clipboard Toggle word wrap

    Example output: 

    job.batch "ocs-osd-removal-job" deleted
    Copy to Clipboard Toggle word wrap
Note

When using an external key management system (KMS) with data encryption, the old OSD encryption key can be removed from the Vault server as it is now an orphan key.

Verfication steps

  1. Verify that there is a new OSD running. 

    $ oc get -n openshift-storage pods -l app=rook-ceph-osd
    Copy to Clipboard Toggle word wrap

    Example output: 

    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
    Copy to Clipboard Toggle word wrap

  2. Verify that there is a new PVC created which is in Bound state. 

    $ oc get -n openshift-storage pvc
    Copy to Clipboard Toggle word wrap

    Example output: 

    NAME                      STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS    AGE
ocs-deviceset-0-0-2s6w4   Bound    pvc-7c9bcaf7-de68-40e1-95f9-0b0d7c0ae2fc   512Gi      RWO            thin            5m
ocs-deviceset-1-0-q8fwh   Bound    pvc-9e7e00cb-6b33-402e-9dc5-b8df4fd9010f   512Gi      RWO            thin            1d20h
ocs-deviceset-2-0-9v8lq   Bound    pvc-38cdfcee-ea7e-42a5-a6e1-aaa6d4924291   512Gi      RWO            thin            1d20h
    Copy to Clipboard Toggle word wrap

  3. (Optional) If cluster-wide encryption is enabled on the cluster, verify that the new OSD devices are encrypted.

    1. Identify the node(s) where the new OSD pod(s) are running. 

      $ oc get -o=custom-columns=NODE:.spec.nodeName pod/<OSD pod name>
      Copy to Clipboard Toggle word wrap

      For example: 

      oc get -o=custom-columns=NODE:.spec.nodeName pod/rook-ceph-osd-0-544db49d7f-qrgqm
      Copy to Clipboard Toggle word wrap

    2. For each of the 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
        Copy to Clipboard Toggle word wrap

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

        $ lsblk
        Copy to Clipboard Toggle word wrap

  4. Log in to OpenShift Web Console and view the storage dashboard.

    Figure 2.1. OSD status in OpenShift Container Platform storage dashboard after device replacement

    RHOCP storage dashboard showing the healthy OSD.
    View larger image
    RHOCP storage dashboard showing the healthy OSD.

Use this procedure when one or more virtual machine disks (VMDK) needs to be replaced in OpenShift Container Storage which is deployed on Red Hat Virtualization infrastructure. This procedure helps to create a new Persistent Volume Claim (PVC) on a new volume and remove the old object storage device (OSD).

Prerequisites

  • Ensure that the data is resilient.

    • On the OpenShift Web console, navigate to Storage → Overview.
    • Under Persistent Storage in the Status card, confirm that the Data Resiliency has a green tick mark.

Procedure

  1. Identify the OSD that needs to be replaced and the OpenShift Container Platform node that has the OSD scheduled on it. 

    $ oc get -n openshift-storage pods -l app=rook-ceph-osd -o wide
    Copy to Clipboard Toggle word wrap

    Example output: 

    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>
    Copy to Clipboard Toggle word wrap

    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.

  2. Scale down the OSD deployment for the OSD to be replaced.

    Each time you want to replace the OSD, repeat this step by updating the osd_id_to_remove parameter with the OSD ID. 

    $ osd_id_to_remove=0
$ oc scale -n openshift-storage deployment rook-ceph-osd-${osd_id_to_remove} --replicas=0
    Copy to Clipboard Toggle word wrap

    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: 

    deployment.extensions/rook-ceph-osd-0 scaled
    Copy to Clipboard Toggle word wrap

  3. Verify that the rook-ceph-osd pod is terminated. 

    $ oc get -n openshift-storage pods -l ceph-osd-id=${osd_id_to_remove}
    Copy to Clipboard Toggle word wrap

    Example output: 

    No resources found.
    Copy to Clipboard Toggle word wrap
    Note

    If the rook-ceph-osd pod is in terminating state, use the force option to delete the pod. 

    $ oc delete pod rook-ceph-osd-0-6d77d6c7c6-m8xj6 --force --grace-period=0
    Copy to Clipboard Toggle word wrap

    Example output: 

    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
    Copy to Clipboard Toggle word wrap

  4. Remove the old OSD from the cluster so that a new OSD can be added.

    1. Delete any old ocs-osd-removal jobs. 

      $ oc delete -n openshift-storage job ocs-osd-removal-job
      Copy to Clipboard Toggle word wrap

      Example output: 

      job.batch "ocs-osd-removal-job"
      Copy to Clipboard Toggle word wrap

    2. Change to the openshift-storage project. 

      $ oc project openshift-storage
      Copy to Clipboard Toggle word wrap

    3. Remove the old OSD from the cluster. 

      $ oc process -n openshift-storage ocs-osd-removal \
-p FAILED_OSD_IDS=<failed_osd_id> FORCE_OSD_REMOVAL=false | oc create -n openshift-storage -f -
      Copy to Clipboard Toggle word wrap
      <failed_osd_id>

      Is the integer in the pod name immediately after the rook-ceph-osd prefix. 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.

  5. Verify that the OSD is 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-job -n openshift-storage
    Copy to Clipboard Toggle word wrap
    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-job -n openshift-storage --tail=-1'
    Copy to Clipboard Toggle word wrap

  6. 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 Container Storage nodes.

    1. Get PVC name(s) of the replaced OSD(s) from the logs of ocs-osd-removal-job pod : 

      $ oc logs -l job-name=ocs-osd-removal-job -n openshift-storage --tail=-1  |egrep -i ‘pvc|deviceset’
      Copy to Clipboard Toggle word wrap

      For example: 

      2021-05-12 14:31:34.666000 I | cephosd: removing the OSD PVC "ocs-deviceset-xxxx-xxx-xxx-xxx"
      Copy to Clipboard Toggle word wrap

    2. For each of the nodes identified in step #1, do the following:

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

        $ oc debug node/<node name>
$ chroot /host
        Copy to Clipboard Toggle word wrap

      2. Find relevant device name based on the PVC names identified in the previous step 

        sh-4.4# dmsetup ls| grep <pvc name>
ocs-deviceset-xxx-xxx-xxx-xxx-block-dmcrypt (253:0)
        Copy to Clipboard Toggle word wrap

      3. Remove the mapped device. 

        $ cryptsetup luksClose --debug --verbose ocs-deviceset-xxx-xxx-xxx-xxx-block-dmcrypt
        Copy to Clipboard Toggle word wrap
        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. 

          $ ps -ef | grep crypt
          Copy to Clipboard Toggle word wrap

        • Terminate the process using kill command. 

          $ kill -9 <PID>
          Copy to Clipboard Toggle word wrap

        • Verify that the device name is removed. 

          $ dmsetup ls
          Copy to Clipboard Toggle word wrap

  7. Delete the ocs-osd-removal job. 

    $ oc delete -n openshift-storage job ocs-osd-removal-job
    Copy to Clipboard Toggle word wrap

    Example output: 

    job.batch "ocs-osd-removal-job" deleted
    Copy to Clipboard Toggle word wrap
Note

When using an external key management system (KMS) with data encryption, the old OSD encryption key can be removed from the Vault server as it is now an orphan key.

Verfication steps

  1. Verify that there is a new OSD running. 

    $ oc get -n openshift-storage pods -l app=rook-ceph-osd
    Copy to Clipboard Toggle word wrap

    Example output: 

    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
    Copy to Clipboard Toggle word wrap

  2. Verify that there is a new PVC created which is in Bound state. 

    $ oc get -n openshift-storage pvc
    Copy to Clipboard Toggle word wrap

  3. (Optional) If cluster-wide encryption is enabled on the cluster, verify that the new OSD devices are encrypted.

    1. Identify the node(s) where the new OSD pod(s) are running. 

      $ oc get -o=custom-columns=NODE:.spec.nodeName pod/<OSD pod name>
      Copy to Clipboard Toggle word wrap

      For example: 

      oc get -o=custom-columns=NODE:.spec.nodeName pod/rook-ceph-osd-0-544db49d7f-qrgqm
      Copy to Clipboard Toggle word wrap

    2. For each of the 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
        Copy to Clipboard Toggle word wrap

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

        $ lsblk
        Copy to Clipboard Toggle word wrap

  4. Log in to OpenShift Web Console and view the storage dashboard.

    Figure 3.1. OSD status in OpenShift Container Platform storage dashboard after device replacement

    RHOCP storage dashboard showing the healthy OSD.
    View larger image
    RHOCP storage dashboard showing the healthy OSD.

When you need to replace a device in a dynamically created storage cluster on an Azure installer-provisioned infrastructure, you must replace the storage node. For information about how to replace nodes, see:

When you need to replace a storage device on an Amazon EC2 (storage-optimized I3) infrastructure, you must replace the storage node. For information about how to replace nodes, see Replacing failed storage nodes on Amazon EC2 infrastructure.

You can replace an object storage device (OSD) in OpenShift Container Storage deployed using local storage devices on the following infrastructures:

  • Bare metal
  • VMware
  • Red Hat Virtualization

Use this procedure when one or more underlying storage devices need to be replaced.

Prerequisites

  • Red Hat recommends that replacement devices are configured with similar infrastructure and resources to the device being replaced.
  • If you upgraded to OpenShift Container Storage 4.7 from a previous version and have not already created a LocalVolumeSet object to enable automatic provisioning of devices, do so now by following the procedure described in Post-update configuration changes for clusters backed by local storage.
  • If you upgraded to OpenShift Container Storage 4.7 from a previous version and have not already created the LocalVolumeDiscovery object, do so now by following the procedure described in Post-update configuration changes for clusters backed by local storage.

  • Ensure that the data is resilient.

    • On the OpenShift Web console, navigate to Storage → Overview.
    • Under Persistent Storage in the Status card, confirm that the Data Resiliency has a green tick mark.

Procedure

  1. Remove the underlying storage device from relevant worker node.

  2. Verify that relevant OSD Pod has moved to CrashLoopBackOff state.

    Identify the OSD that needs to be replaced and the OpenShift Container Platform node that has the OSD scheduled on it. 

    $ oc get -n openshift-storage pods -l app=rook-ceph-osd -o wide
    Copy to Clipboard Toggle word wrap

    Example output: 

    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>
    Copy to Clipboard Toggle word wrap

    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.

  3. Scale down the OSD deployment for the OSD to be replaced. 

    $ osd_id_to_remove=0
$ oc scale -n openshift-storage deployment rook-ceph-osd-${osd_id_to_remove} --replicas=0
    Copy to Clipboard Toggle word wrap

    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: 

    deployment.extensions/rook-ceph-osd-0 scaled
    Copy to Clipboard Toggle word wrap

  4. Verify that the rook-ceph-osd pod is terminated. 

    $ oc get -n openshift-storage pods -l ceph-osd-id=${osd_id_to_remove}
    Copy to Clipboard Toggle word wrap

    Example output: 

    No resources found in openshift-storage namespace.
    Copy to Clipboard Toggle word wrap
    Note

    If the rook-ceph-osd pod is in terminating state for more than a few minutes, use the force option to delete the pod. 

    $ oc delete -n openshift-storage pod rook-ceph-osd-0-6d77d6c7c6-m8xj6 --grace-period=0 --force
    Copy to Clipboard Toggle word wrap

    Example output: 

    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
    Copy to Clipboard Toggle word wrap

  5. Remove the old OSD from the cluster so that a new OSD can be added.

    1. Delete any old ocs-osd-removal jobs. 

      $ oc delete -n openshift-storage job ocs-osd-removal-job
      Copy to Clipboard Toggle word wrap

      Example output: 

      job.batch "ocs-osd-removal-job" deleted
      Copy to Clipboard Toggle word wrap

    2. Change to the openshift-storage project. 

      $ oc project openshift-storage
      Copy to Clipboard Toggle word wrap

    3. Remove the old OSD from the cluster. 

      $ oc process -n openshift-storage ocs-osd-removal \
-p FAILED_OSD_IDS=<failed_osd_id> FORCE_OSD_REMOVAL=false | oc create -n openshift-storage -f -
      Copy to Clipboard Toggle word wrap
      <failed_osd_id>

      Is the integer in the pod name immediately after the rook-ceph-osd prefix. 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.

  6. Verify that the OSD is 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-job -n openshift-storage
    Copy to Clipboard Toggle word wrap
    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-job -n openshift-storage --tail=-1
    Copy to Clipboard Toggle word wrap

  7. 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 Container Storage nodes.

    1. Get PVC name(s) of the replaced OSD(s) from the logs of ocs-osd-removal-job pod : 

      $ oc logs -l job-name=ocs-osd-removal-job -n openshift-storage --tail=-1  |egrep -i ‘pvc|deviceset’
      Copy to Clipboard Toggle word wrap

      For example: 

      2021-05-12 14:31:34.666000 I | cephosd: removing the OSD PVC "ocs-deviceset-xxxx-xxx-xxx-xxx"
      Copy to Clipboard Toggle word wrap

    2. For each of the nodes identified in step #1, do the following:

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

        $ oc debug node/<node name>
$ chroot /host
        Copy to Clipboard Toggle word wrap

      2. Find relevant device name based on the PVC names identified in the previous step 

        sh-4.4# dmsetup ls| grep <pvc name>
ocs-deviceset-xxx-xxx-xxx-xxx-block-dmcrypt (253:0)
        Copy to Clipboard Toggle word wrap

      3. Remove the mapped device. 

        $ cryptsetup luksClose --debug --verbose ocs-deviceset-xxx-xxx-xxx-xxx-block-dmcrypt
        Copy to Clipboard Toggle word wrap
        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. 

          $ ps -ef | grep crypt
          Copy to Clipboard Toggle word wrap

        • Terminate the process using kill command. 

          $ kill -9 <PID>
          Copy to Clipboard Toggle word wrap

        • Verify that the device name is removed. 

          $ dmsetup ls
          Copy to Clipboard Toggle word wrap

  8. Find the persistent volume (PV) that need to be deleted by the command: 

    $ oc get pv -L kubernetes.io/hostname | grep localblock | grep Released

local-pv-d6bf175b           1490Gi       RWO         Delete          Released            openshift-storage/ocs-deviceset-0-data-0-6c5pw      localblock      2d22h       compute-1
    Copy to Clipboard Toggle word wrap

  9. Delete the persistent volume. 

    $ oc delete pv local-pv-d6bf175b
    Copy to Clipboard Toggle word wrap
  10. Physically add a new device to the node.

  11. Use the following command to track provisioning of persistent volumes for devices that match the deviceInclusionSpec. It can take a few minutes to provision persistent volumes. 

    $ oc -n openshift-local-storage describe localvolumeset localblock
    Copy to Clipboard Toggle word wrap

    Example output: 

    [...]
Status:
  Conditions:
    Last Transition Time:          2020-11-17T05:03:32Z
    Message:                       DiskMaker: Available, LocalProvisioner: Available
    Status:                        True
    Type:                          DaemonSetsAvailable
    Last Transition Time:          2020-11-17T05:03:34Z
    Message:                       Operator reconciled successfully.
    Status:                        True
    Type:                          Available
  Observed Generation:             1
  Total Provisioned Device Count: 4
Events:
Type    Reason      Age          From                Message
----    ------      ----         ----                -------
Normal  Discovered  2m30s (x4    localvolumeset-     node.example.com -
        NewDevice   over 2m30s)  symlink-controller  found possible
                                                     matching disk,
                                                     waiting 1m to claim
Normal  FoundMatch  89s (x4      localvolumeset-     node.example.com -
        ingDisk     over 89s)    symlink-controller  symlinking matching
                                                     disk
    Copy to Clipboard Toggle word wrap

    Once the persistent volume is provisioned, a new OSD pod is automatically created for the provisioned volume.

  12. Delete the ocs-osd-removal job(s). 

    $ oc delete -n openshift-storage job ocs-osd-removal-job
    Copy to Clipboard Toggle word wrap

    Example output: 

    job.batch "ocs-osd-removal-job" deleted
    Copy to Clipboard Toggle word wrap
Note

When using an external key management system (KMS) with data encryption, the old OSD encryption key can be removed from the Vault server as it is now an orphan key.

Verification steps

  1. Verify that there is a new OSD running. 

    $ oc get -n openshift-storage pods -l app=rook-ceph-osd
    Copy to Clipboard Toggle word wrap

    Example output: 

    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
    Copy to Clipboard Toggle word wrap
    Note

    If the new OSD does not show as Running after a few minutes, restart the rook-ceph-operator pod to force a reconciliation. 

    $ oc delete pod -n openshift-storage -l app=rook-ceph-operator
    Copy to Clipboard Toggle word wrap

    Example output: 

    pod "rook-ceph-operator-6f74fb5bff-2d982" deleted
    Copy to Clipboard Toggle word wrap

  2. Verify that a new PVC is created. 

    $ oc get -n openshift-storage pvc | grep localblock
    Copy to Clipboard Toggle word wrap

    Example output: 

    ocs-deviceset-0-0-c2mqb   Bound    local-pv-b481410         1490Gi     RWO            localblock                    5m
ocs-deviceset-1-0-959rp   Bound    local-pv-414755e0        1490Gi     RWO            localblock                    1d20h
ocs-deviceset-2-0-79j94   Bound    local-pv-3e8964d3        1490Gi     RWO            localblock                    1d20h
    Copy to Clipboard Toggle word wrap

  3. (Optional) If cluster-wide encryption is enabled on the cluster, verify that the new OSD devices are encrypted.

    1. Identify the node(s) where the new OSD pod(s) are running. 

      $ oc get -o=custom-columns=NODE:.spec.nodeName pod/<OSD pod name>
      Copy to Clipboard Toggle word wrap

      For example: 

      oc get -o=custom-columns=NODE:.spec.nodeName pod/rook-ceph-osd-0-544db49d7f-qrgqm
      Copy to Clipboard Toggle word wrap

    2. For each of the 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
        Copy to Clipboard Toggle word wrap

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

        $ lsblk
        Copy to Clipboard Toggle word wrap

  4. Log in to OpenShift Web Console and check the OSD status on the storage dashboard.

    Figure 5.1. OSD status in OpenShift Container Platform storage dashboard after device replacement

    RHOCP storage dashboard showing the healthy OSD.
    View larger image
    RHOCP storage dashboard showing the healthy OSD.
Note

A full data recovery may take longer depending on the volume of data being recovered.

You can replace an object storage device (OSD) in OpenShift Container Storage deployed using local storage devices on IBM Power Systems. Use this procedure when an underlying storage device needs to be replaced.

Prerequisites

  • Ensure that the data is resilient.

    • On the OpenShift Web console, navigate to Storage → Overview.
    • Under Persistent Storage in the Status card, confirm that the Data Resiliency has a green tick mark.

Procedure

  1. Identify the OSD that needs to be replaced and the OpenShift Container Platform node that has the OSD scheduled on it. 

    $ oc get -n openshift-storage pods -l app=rook-ceph-osd -o wide
    Copy to Clipboard Toggle word wrap

    Example output: 

    rook-ceph-osd-0-86bf8cdc8-4nb5t   0/1     crashLoopBackOff   0   24h   10.129.2.26     worker-0     <none>       <none>
rook-ceph-osd-1-7c99657cfb-jdzvz   1/1     Running   0          24h     10.128.2.46     worker-1     <none>       <none>
rook-ceph-osd-2-5f9f6dfb5b-2mnw9    1/1     Running   0          24h     10.131.0.33    worker-2     <none>       <none>
    Copy to Clipboard Toggle word wrap

    In this example, rook-ceph-osd-0-86bf8cdc8-4nb5t needs to be replaced and worker-0 is the RHOCP node on which the OSD is scheduled.

    Note

    If the OSD to be replaced is healthy, the status of the pod will be Running.

  2. Scale down the OSD deployment for the OSD to be replaced. 

    $ osd_id_to_remove=0
$ oc scale -n openshift-storage deployment rook-ceph-osd-${osd_id_to_remove} --replicas=0
    Copy to Clipboard Toggle word wrap

    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: 

    deployment.apps/rook-ceph-osd-0 scaled
    Copy to Clipboard Toggle word wrap

  3. Verify that the rook-ceph-osd pod is terminated. 

    $ oc get -n openshift-storage pods -l ceph-osd-id=${osd_id_to_remove}
    Copy to Clipboard Toggle word wrap

    Example output: 

    No resources found in openshift-storage namespace.
    Copy to Clipboard Toggle word wrap
    Note

    If the rook-ceph-osd pod is in terminating state, use the force option to delete the pod. 

    $ oc delete -n openshift-storage pod rook-ceph-osd-0-86bf8cdc8-4nb5t --grace-period=0 --force
    Copy to Clipboard Toggle word wrap

    Example output: 

    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-0-86bf8cdc8-4nb5t" force deleted
    Copy to Clipboard Toggle word wrap

  1. Remove the old OSD from the cluster so that a new OSD can be added.

    1. Identify the DeviceSet associated with the OSD to be replaced. 

      $ oc get -n openshift-storage -o yaml deployment rook-ceph-osd-${osd_id_to_remove} | grep ceph.rook.io/pvc
      Copy to Clipboard Toggle word wrap

      Example output: 

      ceph.rook.io/pvc: ocs-deviceset-localblock-0-data-0-64xjl
    ceph.rook.io/pvc: ocs-deviceset-localblock-0-data-0-64xjl
      Copy to Clipboard Toggle word wrap

      In this example, the PVC name is ocs-deviceset-localblock-0-data-0-64xjl.

    2. Delete any old ocs-osd-removal jobs. 

      $ oc delete -n openshift-storage job ocs-osd-removal-job
      Copy to Clipboard Toggle word wrap

      Example output: 

      job.batch "ocs-osd-removal-job" deleted
      Copy to Clipboard Toggle word wrap

    3. Change to the openshift-storage project. 

      $ oc project openshift-storage
      Copy to Clipboard Toggle word wrap

    4. Remove the old OSD from the cluster 

      $ oc process -n openshift-storage ocs-osd-removal -p FAILED_OSD_IDS=${osd_id_to_remove} | oc -n openshift-storage create -f -
      Copy to Clipboard Toggle word wrap

      You can remove more than one OSD by adding comma separated OSD IDs in the command. (For example: FAILED_OSD_IDS=0,1,2)

      Warning

      This step results in OSD being completely removed from the cluster. Make sure that the correct value of osd_id_to_remove is provided.

  2. Verify that the OSD is removed successfully by checking the status of the ocs-osd-removal pod. A status of Completed confirms that the OSD removal job completed successfully. 

    $ oc get pod -l job-name=ocs-osd-removal-job -n openshift-storage
    Copy to Clipboard Toggle word wrap
    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-job -n openshift-storage --tail=-1
    Copy to Clipboard Toggle word wrap

  3. Delete the persistent volume claim (PVC) resources associated with the OSD to be replaced.

    1. Identify the PV associated with the PVC. 

      $ oc get -n openshift-storage pvc ocs-deviceset-<x>-<y>-<pvc-suffix>
      Copy to Clipboard Toggle word wrap

      where, x, y, and pvc-suffix are the values in the DeviceSet identified in an step 4(a).

      Example output: 

      NAME                      STATUS        VOLUME        CAPACITY   ACCESS MODES   STORAGECLASS   AGE
ocs-deviceset-localblock-0-data-0-64xjl   Bound    local-pv-8137c873    256Gi      RWO     localblock     24h
      Copy to Clipboard Toggle word wrap

      In this example, the associated PV is local-pv-8137c873.

    2. Identify the name of the device to be replaced. 

      $ oc get pv local-pv-<pv-suffix> -o yaml | grep path
      Copy to Clipboard Toggle word wrap

      where, pv-suffix is the value in the PV name identified in an earlier step.

      Example output: 

      path: /mnt/local-storage/localblock/vdc
      Copy to Clipboard Toggle word wrap

      In this example, the device name is vdc.

    3. Identify the prepare-pod associated with the OSD to be replaced. 

      $ oc describe -n openshift-storage pvc ocs-deviceset-<x>-<y>-<pvc-suffix> | grep Mounted
      Copy to Clipboard Toggle word wrap

      where, x, y, and pvc-suffix are the values in the DeviceSet identified in an earlier step.

      Example output: 

      Mounted By:    rook-ceph-osd-prepare-ocs-deviceset-localblock-0-data-0-64knzkc
      Copy to Clipboard Toggle word wrap

      In this example the prepare-pod name is rook-ceph-osd-prepare-ocs-deviceset-localblock-0-data-0-64knzkc.

    4. Delete the osd-prepare pod before removing the associated PVC. 

      $ oc delete -n openshift-storage pod rook-ceph-osd-prepare-ocs-deviceset-<x>-<y>-<pvc-suffix>-<pod-suffix>
      Copy to Clipboard Toggle word wrap

      where, x, y, pvc-suffix, and pod-suffix are the values in the osd-prepare pod name identified in an earlier step.

      Example output: 

      job.batch "ocs-osd-removal-job" deleted
      Copy to Clipboard Toggle word wrap

    5. Change to the openshift-storage project. 

      $ oc project openshift-storage
      Copy to Clipboard Toggle word wrap

    6. Remove the old OSD from the cluster 

      $ oc process -n openshift-storage ocs-osd-removal \
-p FAILED_OSD_IDS=<failed_osd_id> FORCE_OSD_REMOVAL=false | oc create -n openshift-storage -f -
      Copy to Clipboard Toggle word wrap
      <failed_osd_id>

      Is the integer in the pod name immediately after the rook-ceph-osd prefix. 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.s

      Warning

      This step results in OSD being completely removed from the cluster. Make sure that the correct value of osd_id_to_remove is provided.

  4. 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. 

    pod "rook-ceph-osd-prepare-ocs-deviceset-localblock-0-data-0-64knzkc" deleted
    Copy to Clipboard Toggle word wrap

    1. Delete the PVC associated with the OSD to be replaced. 

      $ oc delete -n openshift-storage pvc ocs-deviceset-<x>-<y>-<pvc-suffix>
      Copy to Clipboard Toggle word wrap

      where, x, y, and pvc-suffix are the values in the DeviceSet identified in an earlier step.

      Example output: 

      persistentvolumeclaim "ocs-deviceset-localblock-0-data-0-64xjl" deleted
      Copy to Clipboard Toggle word wrap

  5. Delete the PV associated with the device to be replaced, which was identified in earlier steps. In this example, the PV name is local-pv-8137c873. 

    $ oc delete pv local-pv-8137c873
    Copy to Clipboard Toggle word wrap

    Example output: 

    persistentvolume "local-pv-8137c873" deleted
    Copy to Clipboard Toggle word wrap

  6. Replace the old device and use the new device to create a new OpenShift Container Platform PV.

    1. Log in to OpenShift Container Platform node with the device to be replaced. In this example, the OpenShift Container Platform node is worker-0. 

      $ oc debug node/worker-0
      Copy to Clipboard Toggle word wrap

      Example output: 

      Starting pod/worker-0-debug ...
To use host binaries, run `chroot /host`
Pod IP: 192.168.88.21
If you don't see a command prompt, try pressing enter.
# chroot /host
      Copy to Clipboard Toggle word wrap

    2. Record the /dev/disk that is to be replaced using the device name, vdc, identified earlier. 

      # ls -alh /mnt/local-storage/localblock
      Copy to Clipboard Toggle word wrap

      Example output: 

      total 0
drwxr-xr-x. 2 root root 17 Nov  18 15:23 .
drwxr-xr-x. 3 root root 24 Nov  18 15:23 ..
lrwxrwxrwx. 1 root root  8 Nov  18 15:23 vdc -> /dev/vdc
      Copy to Clipboard Toggle word wrap

    3. Find the name of the LocalVolumeSet CR, and remove or comment out the device /dev/disk that is to be replaced. 

      $ oc get -n openshift-local-storage localvolumeset
NAME          AGE
localblock   25h
      Copy to Clipboard Toggle word wrap

  7. Log in to OpenShift Container Platform node with the device to be replaced and remove the old symlink. 

    $ oc debug node/worker-0
    Copy to Clipboard Toggle word wrap

    Example output: 

    Starting pod/worker-0-debug ...
To use host binaries, run `chroot /host`
Pod IP: 192.168.88.21
If you don't see a command prompt, try pressing enter.
# chroot /host
    Copy to Clipboard Toggle word wrap

    1. Identify the old symlink for the device name to be replaced. In this example, the device name is vdc. 

      # ls -alh /mnt/local-storage/localblock
      Copy to Clipboard Toggle word wrap

      Example output: 

      total 0
drwxr-xr-x. 2 root root 17 Nov  18 15:23 .
drwxr-xr-x. 3 root root 24 Nov  18 15:23 ..
lrwxrwxrwx. 1 root root  8 Nov  18 15:23 vdc -> /dev/vdc
      Copy to Clipboard Toggle word wrap

    2. Remove the symlink. 

      # rm /mnt/local-storage/localblock/vdc
      Copy to Clipboard Toggle word wrap

    3. Verify that the symlink is removed. 

      # ls -alh /mnt/local-storage/localblock
      Copy to Clipboard Toggle word wrap

      Example output: 

      total 0
drwxr-xr-x. 2 root root 6 Nov 18 17:11 .
drwxr-xr-x. 3 root root 24 Nov 18 15:23 ..
      Copy to Clipboard Toggle word wrap
      Important

      For new deployments of OpenShift Container Storage 4.5 or later, LVM is not in use, ceph-volume raw mode is in play instead. Therefore, additional validation is not needed and you can proceed to the next step.

  8. Replace the device with the new device.

  9. Log back into the correct OpenShift Cotainer Platform node and identify the device name for the new drive. The device name must change unless you are reseating the same device. 

    # lsblk
    Copy to Clipboard Toggle word wrap

    Example output: 

    NAME                         MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
vda                          252:0    0   40G  0 disk
|-vda1                       252:1    0    4M  0 part
|-vda2                       252:2    0  384M  0 part /boot
`-vda4                       252:4    0 39.6G  0 part
  `-coreos-luks-root-nocrypt 253:0    0 39.6G  0 dm   /sysroot
vdb                          252:16   0  512B  1 disk
vdd                          252:32   0  256G  0 disk
    Copy to Clipboard Toggle word wrap

    In this example, the new device name is vdd.

  10. After the new /dev/disk is available ,it will be auto detected by localvolumeset.

  11. Verify that there is a new PV in Available state and of the correct size. 

    $ oc get pv | grep 256Gi
    Copy to Clipboard Toggle word wrap

    Example output: 

    local-pv-1e31f771   256Gi   RWO    Delete  Bound  openshift-storage/ocs-deviceset-localblock-2-data-0-6xhkf   localblock    24h
local-pv-ec7f2b80   256Gi   RWO    Delete  Bound  openshift-storage/ocs-deviceset-localblock-1-data-0-hr2fx   localblock    24h
local-pv-8137c873   256Gi   RWO    Delete  Available                                                          localblock    32m
    Copy to Clipboard Toggle word wrap

  12. Create new OSD for new device.

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

      1. Identify the name of the rook-ceph-operator. 

        $ oc get -n openshift-storage pod -l app=rook-ceph-operator
        Copy to Clipboard Toggle word wrap

        Example output: 

        NAME                                  READY   STATUS    RESTARTS   AGE
rook-ceph-operator-85f6494db4-sg62v   1/1     Running   0          1d20h
        Copy to Clipboard Toggle word wrap

      2. Delete the rook-ceph-operator. 

        $ oc delete -n openshift-storage pod rook-ceph-operator-85f6494db4-sg62v
        Copy to Clipboard Toggle word wrap

        Example output: 

        pod "rook-ceph-operator-85f6494db4-sg62v" deleted
        Copy to Clipboard Toggle word wrap

        In this example, the rook-ceph-operator pod name is rook-ceph-operator-85f6494db4-sg62v.

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

        $ oc get -n openshift-storage pod -l app=rook-ceph-operator
        Copy to Clipboard Toggle word wrap

        Example output: 

        NAME                                  READY   STATUS    RESTARTS   AGE
rook-ceph-operator-85f6494db4-wx9xx   1/1     Running   0          50s
        Copy to Clipboard Toggle word wrap

        Creation of the new OSD may take several minutes after the operator restarts.

  13. Delete the ocs-osd-removal job(s). 

    $ oc delete -n openshift-storage job ocs-osd-removal-job
    Copy to Clipboard Toggle word wrap

    Example output: 

    job.batch "ocs-osd-removal-job" deleted
    Copy to Clipboard Toggle word wrap

Verfication steps

  • Verify that there is a new OSD running and a new PVC created. 

    $ oc get -n openshift-storage pods -l app=rook-ceph-osd
    Copy to Clipboard Toggle word wrap

    Example output: 

    rook-ceph-osd-0-76d8fb97f9-mn8qz   1/1     Running   0          23m
rook-ceph-osd-1-7c99657cfb-jdzvz   1/1     Running   1          25h
rook-ceph-osd-2-5f9f6dfb5b-2mnw9   1/1     Running   0          25h
    Copy to Clipboard Toggle word wrap 
    $ oc get -n openshift-storage pvc | grep localblock
    Copy to Clipboard Toggle word wrap

    Example output: 

    ocs-deviceset-localblock-0-data-0-q4q6b   Bound    local-pv-8137c873       256Gi     RWO         localblock         10m
ocs-deviceset-localblock-1-data-0-hr2fx   Bound    local-pv-ec7f2b80       256Gi     RWO         localblock         1d20h
ocs-deviceset-localblock-2-data-0-6xhkf   Bound    local-pv-1e31f771       256Gi     RWO         localblock         1d20h
    Copy to Clipboard Toggle word wrap

  • Log in to OpenShift Web Console and view the storage dashboard.

    Figure 5.2. OSD status in OpenShift Container Platform storage dashboard after device replacement

    RHOCP storage dashboard showing the healthy OSD.
    View larger image
    RHOCP storage dashboard showing the healthy OSD.

You can replace operational or failed storage devices on IBM Z or LinuxONE infrastructure with new SCSI disks.

IBM Z or LinuxONE supports SCSI FCP disk logical units (SCSI disks) as persistent storage devices from external disk storage. A SCSI disk can be identified by using its FCP Device number, two target worldwide port names (WWPN1 and WWPN2), and the logical unit number (LUN). For more information, see https://www.ibm.com/support/knowledgecenter/SSB27U_6.4.0/com.ibm.zvm.v640.hcpa5/scsiover.html

Prerequisites

  • Ensure that the data is resilient.

    • On the OpenShift Web console, navigate to Storage → Overview.
    • Under Persistent Storage in the Status card, confirm that the Data Resiliency has a green tick mark.

Procedure

  1. List all the disks with the following command. 

    $ lszdev
    Copy to Clipboard Toggle word wrap

    Example output: 

    TYPE         ID
zfcp-host    0.0.8204                                        yes  yes
zfcp-lun     0.0.8204:0x102107630b1b5060:0x4001402900000000 yes  no    sda sg0
zfcp-lun     0.0.8204:0x500407630c0b50a4:0x3002b03000000000  yes  yes   sdb sg1
qeth         0.0.bdd0:0.0.bdd1:0.0.bdd2                      yes  no    encbdd0
generic-ccw  0.0.0009                                        yes  no
    Copy to Clipboard Toggle word wrap

    A SCSI disk is represented as a zfcp-lun with the structure <device-id>:<wwpn>:<lun-id> in the ID section. The first disk is used for the operating system. If one storage device fails, it can be replaced with a new disk.

  2. Remove the disk.

    Run the following command on the disk, replacing scsi-id with the SCSI disk identifier of the disk to be replaced. 

    $ chzdev -d scsi-id
    Copy to Clipboard Toggle word wrap

    For example, the following command removes one disk with the device ID 0.0.8204, the WWPN 0x500507630a0b50a4, and the LUN 0x4002403000000000 with the following command: 

    $ chzdev -d 0.0.8204:0x500407630c0b50a4:0x3002b03000000000
    Copy to Clipboard Toggle word wrap

  3. Append a new SCSI disk with the following command: 

    $ chzdev -e 0.0.8204:0x500507630b1b50a4:0x4001302a00000000
    Copy to Clipboard Toggle word wrap
    Note

    The device ID for the new disk must be the same as the disk to be replaced. The new disk is identified with its WWPN and LUN ID.

  4. List all the FCP devices to verify the new disk is configured. 

    $ lszdev zfcp-lun
TYPE         ID                                              ON   PERS  NAMES
zfcp-lun     0.0.8204:0x102107630b1b5060:0x4001402900000000 yes  no    sda sg0
zfcp-lun     0.0.8204:0x500507630b1b50a4:0x4001302a00000000  yes  yes   sdb sg1
    Copy to Clipboard Toggle word wrap
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