Chapter 4. Rebooting the overcloud

Procedure

1. Log in to the node that you want to reboot.

2. Optional: If the node uses Pacemaker resources, stop the cluster:

   [heat-admin@overcloud-controller-0 ~]$ sudo pcs cluster stop

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3. Reboot the node:

   [heat-admin@overcloud-controller-0 ~]$ sudo reboot

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4. Wait until the node boots.

5. Check the services. For example:

   1. If the node uses Pacemaker services, check the node has rejoined the cluster:

      [heat-admin@overcloud-controller-0 ~]$ sudo pcs status

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   2. If the node uses Systemd services, check all services are enabled:

      [heat-admin@overcloud-controller-0 ~]$ sudo systemctl status

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   3. If the node uses containerized services, check all containers on the node are active:

      [heat-admin@overcloud-controller-0 ~]$ sudo podman ps

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Procedure

1. Log in to a Ceph MON or Controller node and disable Ceph Storage cluster rebalancing temporarily:

   $ sudo podman exec -it ceph-mon-controller-0 ceph osd set noout
   $ sudo podman exec -it ceph-mon-controller-0 ceph osd set norebalance

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2. Select the first Ceph Storage node to reboot and log into the node.

3. Reboot the node:

   $ sudo reboot

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4. Wait until the node boots.

5. Log in to the node and check the cluster status:

   $ sudo podman exec -it ceph-mon-controller-0 ceph status

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   Check the pgmap reports all pgs as normal (active+clean).

6. Log out of the node, reboot the next node, and check its status. Repeat this process until you have rebooted all Ceph storage nodes.

7. When complete, log into a Ceph MON or Controller node and enable cluster rebalancing again:

   $ sudo podman exec -it ceph-mon-controller-0 ceph osd unset noout
   $ sudo podman exec -it ceph-mon-controller-0 ceph osd unset norebalance

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8. Perform a final status check to verify the cluster reports HEALTH_OK:

   $ sudo podman exec -it ceph-mon-controller-0 ceph status

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Procedure

1. Log in to the undercloud as the stack user.

2. List all Compute nodes and their UUIDs:

   $ source ~/stackrc
   (undercloud) $ openstack server list --name compute

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   Identify the UUID of the Compute node you want to reboot.

3. From the undercloud, select a Compute Node. Disable the node:

   $ source ~/overcloudrc
   (overcloud) $ openstack compute service list
   (overcloud) $ openstack compute service set [hostname] nova-compute --disable

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4. List all instances on the Compute node:

   (overcloud) $ openstack server list --host [hostname] --all-projects

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5. If you decided not to migrate instances, skip to this step.

6. If you decided to migrate the instances to another Compute node, use one of the following commands:

   1. Migrate the instance to a different host:

      (overcloud) $ openstack server migrate [instance-id] --live [target-host]--wait

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   2. Let nova-scheduler automatically select the target host:

      (overcloud) $ nova live-migration [instance-id]

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   3. Live migrate all instances at once:

      $ nova host-evacuate-live [hostname]

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      Note

      The nova command might cause some deprecation warnings, which are safe to ignore.

7. Wait until migration completes.

8. Confirm the migration was successful:

   (overcloud) $ openstack server list --host [hostname] --all-projects

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9. Continue migrating instances until none remain on the chosen Compute Node.

10. Log in to the Compute Node. Reboot the node:

    [heat-admin@overcloud-compute-0 ~]$ sudo reboot

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11. Wait until the node boots.

12. Enable the Compute Node again:

    $ source ~/overcloudrc
    (overcloud) $ openstack compute service set [hostname] nova-compute --enable

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13. Check whether the Compute node is enabled:

    (overcloud) $ openstack compute service list

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Procedure

1. Log in to a Ceph MON or a Controller node and identify the name of the Ceph MON container:

   $ sudo podman ps | grep -i ceph | grep -i mon
   
   45fe68d340e5  docker-registry.upshift.redhat.com/ceph/rhceph-4.0-rhel8:latest

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2. Set the CEPH_MON_CONTAINER variable to the name of the container:

   $ CEPH_MON_CONTAINER=ceph-mon-controller-0

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3. Verify that you can use the CEPH_MON_CONTAINER variable to run Ceph commands:

   $ sudo podman exec $CEPH_MON_CONTAINER ceph -s

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4. From the Ceph MON or Controller node, disable Ceph Storage cluster rebalancing temporarily:

   $ sudo podman exec $CEPH_MON_CONTAINER ceph osd set noout
   $ sudo podman exec $CEPH_MON_CONTAINER ceph osd set norebalance

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5. Log in to the undercloud as the stack user.

6. List all Compute nodes and their UUIDs:

   $ source ~/stackrc
   (undercloud) $ openstack server list --name compute

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   Identify the UUID of the Compute node you aim to reboot.

7. From the undercloud, select a Compute node and disable it:

   $ source ~/overcloudrc
   (overcloud) $ openstack compute service list
   (overcloud) $ openstack compute service set [hostname] nova-compute --disable

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8. List all instances on the Compute node:

   (overcloud) $ openstack server list --host [hostname] --all-projects

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9. Use one of the following commands to migrate your instances:

   1. Migrate the instance to a specific host of your choice:

      (overcloud) $ openstack server migrate [instance-id] --live [target-host]--wait

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   2. Let nova-scheduler automatically select the target host:

      (overcloud) $ nova live-migration [instance-id]

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   3. Live migrate all instances at once:

      $ nova host-evacuate-live [hostname]

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      Note

      The nova command might cause some deprecation warnings, which are safe to ignore.

10. Wait until the migration completes.

11. Confirm that the migration was successful:

    (overcloud) $ openstack server list --host [hostname] --all-projects

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12. Continue migrating instances until none remain on the chosen Compute node.

13. Log in to a Ceph MON or a Controller node and check the cluster status:

    $ sudo podman exec $CEPH_MON_CONTAINER ceph -s

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    Check that the pgmap reports all pgs as normal (active+clean).

14. Reboot the Compute HCI node:

    $ sudo reboot

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15. Wait until the node boots.

16. Enable the Compute node again:

    $ source ~/overcloudrc
    (overcloud) $ openstack compute service set [hostname] nova-compute --enable

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17. Verify that the Compute node is enabled:

    (overcloud) $ openstack compute service list

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18. Log out of the node, reboot the next node, and check its status. Repeat this process until you have rebooted all Ceph storage nodes.

19. When complete, log in to a Ceph MON or Controller node and enable cluster rebalancing again:

    $ sudo podman exec $CEPH_MON_CONTAINER ceph osd unset noout
    $ sudo podman exec $CEPH_MON_CONTAINER ceph osd unset norebalance

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20. Perform a final status check to verify the cluster reports HEALTH_OK:

    $ sudo podman exec $CEPH_MON_CONTAINER ceph status

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