Chapter 21. Rebooting nodes

Procedure

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

2. Reboot the undercloud:

   $ sudo reboot

3. Wait until the node boots.

Procedure

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

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

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

3. Reboot the node:

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

4. Wait until the node boots.

Verification

1. Verify that the services are enabled.

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

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

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

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

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

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

Procedure

1. Log in to a Ceph MON node.

2. Reboot the node:

   $ sudo reboot

3. Wait until the node boots and rejoins the MON cluster.

Procedure

1. Log in to a Ceph Monitor or Controller node that is running the ceph-mon service, and disable Ceph Storage cluster rebalancing temporarily:

   $ sudo cephadm shell -- ceph osd set noout
   $ sudo cephadm shell -- ceph osd set norebalance

   Note

   If you have a multistack or distributed compute node (DCN) architecture, you must specify the Ceph cluster name when you set the noout and norebalance flags. For example: sudo cephadm shell -c /etc/ceph/<cluster>.conf -k /etc/ceph/<cluster>.client.keyring.

2. Select the first Ceph Storage node that you want to reboot and log in to the node.

3. Reboot the node:

   $ sudo reboot

4. Wait until the node boots.

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

   $ sudo cephadm -- shell ceph status

   Check that 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 in to a Ceph Monitor or Controller node that is running the ceph-mon service and enable Ceph cluster rebalancing:

   $ sudo cephadm shell -- ceph osd unset noout
   $ sudo cephadm shell -- ceph osd unset norebalance

   Note

   If you have a multistack or distributed compute node (DCN) architecture, you must specify the Ceph cluster name when you unset the noout and norebalance flags. For example: sudo cephadm shell -c /etc/ceph/<cluster>.conf -k /etc/ceph/<cluster>.client.keyring

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

   $ sudo cephadm shell ceph status

Procedure

1. Log in to an Object Storage node.

2. Reboot the node:

   $ sudo reboot

3. Wait until the node boots.
4. Repeat the reboot for each Object Storage node in the cluster.

Migrating instances workflow

1. Decide whether to migrate instances to another Compute node before rebooting the node.
2. Select and disable the Compute node that you want to reboot so that it does not provision new instances.
3. Migrate the instances to another Compute node.
4. Reboot the empty Compute node.
5. Enable the empty Compute node.

Procedure

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

2. List all Compute nodes and their UUIDs:

   $ source ~/stackrc
   (undercloud) $ metalsmith list | grep compute

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

3. From the overcloud, select a Compute node and disable it:

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

   • Replace <hostname> with the hostname of your Compute node.

4. List all instances on the Compute node:

   (overcloud)$ openstack server list --host <hostname> --all-projects

5. Optional: To migrate the instances to another Compute node, complete the following steps:

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

      • To migrate the instance to a different host, run the following command:

        (overcloud) $ openstack server migrate <instance_id> --live <target_host> --wait

        • Replace <instance_id> with your instance ID.
        • Replace <target_host> with the host that you are migrating the instance to.

      • Let nova-scheduler automatically select the target host:

        (overcloud) $ nova live-migration <instance_id>

      • Live migrate all instances at once:

        $ nova host-evacuate-live <hostname>

        Note

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

   2. Wait until migration completes.

   3. Confirm that the migration was successful:

      (overcloud) $ openstack server list --host <hostname> --all-projects

   4. Continue to migrate instances until none remain on the Compute node.

6. Log in to the Compute node and reboot the node:

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

7. Wait until the node boots.

8. Re-enable the Compute node:

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

9. Check that the Compute node is enabled:

   (overcloud) $ openstack compute service list