Chapter 10. Restoring the monitor pods in OpenShift Data Foundation

Restore the monitor pods if all three of them go down, and when OpenShift Data Foundation is not able to recover the monitor pods automatically.

Procedure

  1. Scale down the rook-ceph-operator and ocs operator deployments.

    # oc scale deployment rook-ceph-operator --replicas=0 -n openshift-storage
    # oc scale deployment ocs-operator --replicas=0 -n openshift-storage
  2. Create a backup of all deployments in openshift-storage namespace.

    # mkdir backup
    # cd backup
    # oc project openshift-storage
    # for d in $(oc get deployment|awk -F' ' '{print $1}'|grep -v NAME); do echo $d;oc get deployment $d -o yaml > oc_get_deployment.${d}.yaml; done
  3. Patch the OSD deployments to remove the livenessProbe parameter, and run it with the command parameter as sleep.

    # for i in $(oc get deployment -l app=rook-ceph-osd -oname);do oc patch ${i} -n openshift-storage --type='json' -p '[{"op":"remove", "path":"/spec/template/spec/containers/0/livenessProbe"}]' ; oc patch ${i} -n openshift-storage -p '{"spec": {"template": {"spec": {"containers": [{"name": "osd", "command": ["sleep", "infinity"], "args": []}]}}}}' ; done
  4. Retrieve the monstore cluster map from all the OSDs.

    1. Create the recover_mon.sh script.

      #!/bin/bash
      ms=/tmp/monstore
      
      rm -rf $ms
      mkdir $ms
      
      for osd_pod in $(oc get po -l app=rook-ceph-osd -oname -n openshift-storage); do
      
        echo "Starting with pod: $osd_pod"
      
        podname=$(echo $osd_pod|sed 's/pod\///g')
        oc exec $osd_pod -- rm -rf $ms
        oc cp $ms $podname:$ms
      
        rm -rf $ms
        mkdir $ms
      
        echo "pod in loop: $osd_pod ; done deleting local dirs"
      
        oc exec $osd_pod -- ceph-objectstore-tool --type bluestore --data-path /var/lib/ceph/osd/ceph-$(oc get $osd_pod -ojsonpath='{ .metadata.labels.ceph_daemon_id }') --op update-mon-db --no-mon-config --mon-store-path $ms
        echo "Done with COT on pod: $osd_pod"
      
        oc cp $podname:$ms $ms
      
        echo "Finished pulling COT data from pod: $osd_pod"
      done
    2. Run the recover_mon.sh script.

      # chmod +x recover_mon.sh
      # ./recover_mon.sh
  5. Patch the MON deployments, and run it with the command parameter as sleep.

    1. Edit the MON deployments.

      # for i in $(oc get deployment -l app=rook-ceph-mon -oname);do oc patch ${i} -n openshift-storage -p '{"spec": {"template": {"spec": {"containers": [{"name": "mon", "command": ["sleep", "infinity"], "args": []}]}}}}'; done
    2. Patch the MON deployments to increase the initialDelaySeconds.

      # oc get deployment rook-ceph-mon-a -o yaml | sed "s/initialDelaySeconds: 10/initialDelaySeconds: 2000/g" | oc replace -f -
      # oc get deployment rook-ceph-mon-b -o yaml | sed "s/initialDelaySeconds: 10/initialDelaySeconds: 2000/g" | oc replace -f -
      # oc get deployment rook-ceph-mon-c -o yaml | sed "s/initialDelaySeconds: 10/initialDelaySeconds: 2000/g" | oc replace -f -
  6. Copy the previously retrieved monstore to the mon-a pod.

    # oc cp /tmp/monstore/ $(oc get po -l app=rook-ceph-mon,mon=a -oname |sed 's/pod\///g'):/tmp/
  7. Navigate into the MON pod and change the ownership of the retrieved monstore.

    # oc rsh $(oc get po -l app=rook-ceph-mon,mon=a -oname)
    # chown -R ceph:ceph /tmp/monstore
  8. Copy the keyring template file before rebuilding the mon db.

    # oc rsh $(oc get po -l app=rook-ceph-mon,mon=a -oname)
    # cp /etc/ceph/keyring-store/keyring /tmp/keyring
    # cat /tmp/keyring
      [mon.]
        key = AQCleqldWqm5IhAAgZQbEzoShkZV42RiQVffnA==
        caps mon = "allow *"
      [client.admin]
        key = AQCmAKld8J05KxAArOWeRAw63gAwwZO5o75ZNQ==
        auid = 0
        caps mds = "allow *"
        caps mgr = "allow *"
        caps mon = "allow *"
        caps osd = "allow *”
  9. Identify the keyring of all other Ceph daemons (MGR, MDS, RGW, Crash, CSI and CSI provisioners) from its respective secrets.

    # oc get secret rook-ceph-mds-ocs-storagecluster-cephfilesystem-a-keyring -ojson  | jq .data.keyring | xargs echo | base64 -d
    
    [mds.ocs-storagecluster-cephfilesystem-a]
    key = AQB3r8VgAtr6OhAAVhhXpNKqRTuEVdRoxG4uRA==
    caps mon = "allow profile mds"
    caps osd = "allow *"
    caps mds = "allow"

    Example keyring file, /etc/ceph/ceph.client.admin.keyring:

    [mon.]
    	key = AQDxTF1hNgLTNxAAi51cCojs01b4I5E6v2H8Uw==
    	caps mon = "allow "
    [client.admin]
            key = AQDxTF1hpzguOxAA0sS8nN4udoO35OEbt3bqMQ==
            caps mds = "allow " caps mgr = "allow *" caps mon = "allow *" caps osd = "allow *" [mds.ocs-storagecluster-cephfilesystem-a] key = AQCKTV1horgjARAA8aF/BDh/4+eG4RCNBCl+aw== caps mds = "allow" caps mon = "allow profile mds" caps osd = "allow *" [mds.ocs-storagecluster-cephfilesystem-b] key = AQCKTV1hN4gKLBAA5emIVq3ncV7AMEM1c1RmGA== caps mds = "allow" caps mon = "allow profile mds" caps osd = "allow *" [client.rgw.ocs.storagecluster.cephobjectstore.a] key = AQCOkdBixmpiAxAA4X7zjn6SGTI9c1MBflszYA== caps mon = "allow rw" caps osd = "allow rwx" [mgr.a] key = AQBOTV1hGYOEORAA87471+eIZLZtptfkcHvTRg== caps mds = "allow *" caps mon = "allow profile mgr" caps osd = "allow *" [client.crash] key = AQBOTV1htO1aGRAAe2MPYcGdiAT+Oo4CNPSF1g== caps mgr = "allow rw" caps mon = "allow profile crash" [client.csi-cephfs-node] key = AQBOTV1hiAtuBBAAaPPBVgh1AqZJlDeHWdoFLw== caps mds = "allow rw" caps mgr = "allow rw" caps mon = "allow r" caps osd = "allow rw tag cephfs *=" [client.csi-cephfs-provisioner] key = AQBNTV1hHu6wMBAAzNXZv36aZJuE1iz7S7GfeQ== caps mgr = "allow rw" caps mon = "allow r" caps osd = "allow rw tag cephfs metadata="
    [client.csi-rbd-node]
    	key = AQBNTV1h+LnkIRAAWnpIN9bUAmSHOvJ0EJXHRw==
    	caps mgr = "allow rw"
    	caps mon = "profile rbd"
    	caps osd = "profile rbd"
    [client.csi-rbd-provisioner]
    	key = AQBNTV1hMNcsExAAvA3gHB2qaY33LOdWCvHG/A==
    	caps mgr = "allow rw"
    	caps mon = "profile rbd"
    	caps osd = "profile rbd"
    Important
    • For client.csi related keyring, refer to the previous keyring file output and add the default caps after fetching the key from its respective OpenShift Data Foundation secret.
    • OSD keyring is added automatically post recovery.
  10. Navigate into the mon-a pod, and verify that the monstore has monmap.

    1. Navigate into the mon-a pod.

      # oc rsh $(oc get po -l app=rook-ceph-mon,mon=a -oname)
    2. Verify that the monstore has monmap.

      # ceph-monstore-tool /tmp/monstore get monmap -- --out /tmp/monmap
      # monmaptool /tmp/monmap --print
  11. Optional: If the monmap is missing then create a new monmap.

    # monmaptool --create --add <mon-a-id> <mon-a-ip> --add <mon-b-id> <mon-b-ip> --add <mon-c-id> <mon-c-ip> --enable-all-features --clobber /root/monmap --fsid <fsid>
    <mon-a-id>
    Is the ID of the mon-a pod.
    <mon-a-ip>
    Is the IP address of the mon-a pod.
    <mon-b-id>
    Is the ID of the mon-b pod.
    <mon-b-ip>
    Is the IP address of the mon-b pod.
    <mon-c-id>
    Is the ID of the mon-c pod.
    <mon-c-ip>
    Is the IP address of the mon-c pod.
    <fsid>
    Is the file system ID.
  12. Verify the monmap.

    # monmaptool /root/monmap --print
  13. Import the monmap.

    Important

    Use the previously created keyring file.

    # ceph-monstore-tool /tmp/monstore rebuild -- --keyring /tmp/keyring --monmap /root/monmap
    # chown -R ceph:ceph /tmp/monstore
  14. Create a backup of the old store.db file.

    # mv /var/lib/ceph/mon/ceph-a/store.db /var/lib/ceph/mon/ceph-a/store.db.corrupted
    # mv /var/lib/ceph/mon/ceph-b/store.db /var/lib/ceph/mon/ceph-b/store.db.corrupted
    # mv /var/lib/ceph/mon/ceph-c/store.db /var/lib/ceph/mon/ceph-c/store.db.corrupted
  15. Copy the rebuild store.db file to the monstore directory.

    # mv /tmp/monstore/store.db /var/lib/ceph/mon/ceph-a/store.db
    # chown -R ceph:ceph /var/lib/ceph/mon/ceph-a/store.db
  16. After rebuilding the monstore directory, copy the store.db file from local to the rest of the MON pods.

    # oc cp $(oc get po -l app=rook-ceph-mon,mon=a -oname | sed 's/pod\///g'):/var/lib/ceph/mon/ceph-a/store.db /tmp/store.db
    # oc cp /tmp/store.db $(oc get po -l app=rook-ceph-mon,mon=<id> -oname | sed 's/pod\///g'):/var/lib/ceph/mon/ceph-<id>
    <id>
    Is the ID of the MON pod
  17. Navigate into the rest of the MON pods and change the ownership of the copied monstore.

    # oc rsh $(oc get po -l app=rook-ceph-mon,mon=<id> -oname)
    # chown -R ceph:ceph /var/lib/ceph/mon/ceph-<id>/store.db
    <id>
    Is the ID of the MON pod
  18. Revert the patched changes.

    • For MON deployments:

      # oc replace --force -f <mon-deployment.yaml>
      <mon-deployment.yaml>
      Is the MON deployment yaml file
    • For OSD deployments:

      # oc replace --force -f <osd-deployment.yaml>
      <osd-deployment.yaml>
      Is the OSD deployment yaml file
    • For MGR deployments:

      # oc replace --force -f <mgr-deployment.yaml>
      <mgr-deployment.yaml>

      Is the MGR deployment yaml file

      Important

      Ensure that the MON, MGR and OSD pods are up and running.

  19. Scale up the rook-ceph-operator and ocs-operator deployments.

    # oc -n openshift-storage scale deployment ocs-operator --replicas=1

Verification steps

  1. Check the Ceph status to confirm that CephFS is running.

    # ceph -s

    Example output:

    cluster:
       id:     f111402f-84d1-4e06-9fdb-c27607676e55
       health: HEALTH_ERR
                1 filesystem is offline
                1 filesystem is online with fewer MDS than max_mds
                3 daemons have recently crashed
    
       services:
         mon: 3 daemons, quorum b,c,a (age 15m)
         mgr: a(active, since 14m)
         mds: ocs-storagecluster-cephfilesystem:0
         osd: 3 osds: 3 up (since 15m), 3 in (since 2h)
    
       data:
         pools:   3 pools, 96 pgs
         objects: 500 objects, 1.1 GiB
         usage:   5.5 GiB used, 295 GiB / 300 GiB avail
         pgs:     96 active+clean
    Important

    If the filesystem is offline or MDS service is missing, you need to restore the CephFS. For more information, see Section 10.1, “Restoring the CephFS”.

  2. Check the Multicloud Object Gateway (MCG) status. It should be active, and the backingstore and bucketclass should be in Ready state.

    noobaa status -n openshift-storage
    Important

    If the MCG is not in the active state, and the backingstore and bucketclass not in the Ready state, you need to restart all the MCG related pods. For more information, see Section 10.2, “Restoring the Multicloud Object Gateway”.

10.1. Restoring the CephFS

If the filesystem is offline or MDS service is missing you need to restore the CephFS.

Procedure

  1. Scale down the rook-ceph-operator and ocs operator deployments.

    # oc scale deployment rook-ceph-operator --replicas=0 -n openshift-storage
    # oc scale deployment ocs-operator --replicas=0 -n openshift-storage
  2. Patch the MDS deployments to remove the livenessProbe parameter and run it with the command parameter as sleep.

    # for i in $(oc get deployment -l app=rook-ceph-mds -oname);do oc patch ${i} -n openshift-storage --type='json' -p '[{"op":"remove", "path":"/spec/template/spec/containers/0/livenessProbe"}]' ; oc patch ${i} -n openshift-storage -p '{"spec": {"template": {"spec": {"containers": [{"name": "mds", "command": ["sleep", "infinity"], "args": []}]}}}}' ; done
  3. Recover the CephFS.

    # ceph fs reset ocs-storagecluster-cephfilesystem --yes-i-really-mean-it

    If the reset command fails, force create the default filesystem with the data and metadata pools, and then reset it.

    Note

    The reset command might fail if the cephfilesystem is missing.

    # ceph fs new ocs-storagecluster-cephfilesystem ocs-storagecluster-cephfilesystem-metadata ocs-storagecluster-cephfilesystem-data0 --force
    # ceph fs reset ocs-storagecluster-cephfilesystem --yes-i-really-mean-it
  4. Replace the MDS deployments.

    # oc replace --force -f oc_get_deployment.rook-ceph-mds-ocs-storagecluster-cephfilesystem-a.yaml
    # oc replace --force -f oc_get_deployment.rook-ceph-mds-ocs-storagecluster-cephfilesystem-b.yaml
  5. Scale up the rook-ceph-operator and ocs-operator deployments.

    # oc scale deployment ocs-operator --replicas=1 -n openshift-storage
  6. Check the CephFS status.

    # ceph fs status

    The status should be active.

Important
  • If the application pods attached to the deployments which were using the CephFS Persistent Volume Claims (PVCs) get stuck in CreateContainerError state post restoring the CephFS, restart the application pods.

    # oc -n <namespace> delete pods <cephfs-app-pod>
    <namespace>
    Is the project namespace
    <cephfs-app-pod>
    Is the name of the CephFS application pod
  • If new CephFS or RBD PVCs are not getting bound, restart all the pods related to Ceph CSI.

10.2. Restoring the Multicloud Object Gateway

If the Multicloud Object Gateway (MCG) is not in the active state, and the backingstore and bucketclass is not in the Ready state, you need to restart all the MCG related pods, and check the MCG status to confirm that the MCG is back up and running.

Procedure

  1. Restart all the pods related to the MCG.

    # oc delete pods <noobaa-operator> -n openshift-storage
    # oc delete pods <noobaa-core> -n openshift-storage
    # oc delete pods <noobaa-endpoint> -n openshift-storage
    # oc delete pods <noobaa-db> -n openshift-storage
    <noobaa-operator>
    Is the name of the MCG operator
    <noobaa-core>
    Is the name of the MCG core pod
    <noobaa-endpoint>
    Is the name of the MCG endpoint
    <noobaa-db>
    Is the name of the MCG db pod
  2. If the RADOS Object Gateway (RGW) is configured, restart the pod.

    # oc delete pods <rgw-pod> -n openshift-storage
    <rgw-pod>
    Is the name of the RGW pod