Chapter 3. Rebooting Compute nodes You can reboot your Compute nodes any time after you complete the minor update. You check which updated nodes require a reboot first, and then specify them in an OpenStackDatPlaneDeployment custom resource (CR) to start the reboot. Until after the reboot, your environment still uses the old kernel and Open vSwitch (OVS) for data plane development kit (DPDK) implementations. To ensure minimal downtime of instances in your Red Hat OpenStack Services on OpenShift (RHOSO) environment, you should migrate the instances from the Compute node that you need to reboot. Prerequisites You have decided whether to migrate instances to another Compute node before you start the reboot. Note If you have a Multi-RHEL environment, and you want to migrate virtual machines from a Compute node that is running RHEL 9.4 to a Compute node that is running RHEL 9.2, only cold migration is supported. If you cannot migrate the instances, you can set the shutdown_timeout configuration option to control the state of the instances after the Compute node reboots. This option determines the number of seconds to wait for an instance to perform a clean shutdown. The default value is 60 . Procedure Confirm which updated nodes need a reboot: Replace <deployment_name> with the name of the deployment that includes your Compute nodes. Replace <nodeSet_name> with the names of the node sets that you need to check. The command shows the following output if a reboot is required: Reboot is required but was not started. Edpm_reboot_strategy is set to never or this is already deployed machine. Reboot has to be planned. To start reboot set edpm_reboot_strategy to force . Open a remote shell connection to the OpenStackClient pod: Retrieve a list of your Compute nodes to identify the host name of the nodes that require a reboot: Disable the Compute service on the Compute node that you need to reboot: Replace <hostname> with the host name of the Compute node on which you are disabling the service. List all instances on the Compute node: USD openstack server list --host <hostname> --all-projects Optional: If you decide to migrate the instances to another Compute node, for example, if you plan to reboot nodes that include running workloads, run the following command: USD openstack server migrate --live-migration --host <target_host> --wait <instance_id> Replace <instance_id> with your instance ID. Replace <target_host> with the host that you are migrating the instance to. Wait until migration completes. Confirm that the migration was successful: USD openstack server list --host <hostname> --all-projects Continue to migrate instances until none remain on the Compute node. Exit the OpenStackClient pod: Create an OpenStackDataPlaneDeployment CR to reboot the nodes: apiVersion: dataplane.openstack.org/v1beta1 kind: OpenStackDataPlaneDeployment metadata: name: openstack-edpm-ipam-reboot namespace: openstack spec: nodeSets: 1 - <nodeSet_name> servicesOverride: 2 - reboot-os ansibleExtraVars: 3 edpm_reboot_strategy: force ansibleLimit: <node_hostname>,...,<node_hostname> 4 1 Lists the OpenStackDataPlaneNodeSet CRs that contain the nodes that you are rebooting. 2 Specifies the reboot-os as the only service to execute. 3 Reboots all the nodes in the node set at the same time. 4 Optional: Lists the individual nodes in the node set to reboot. If not set, all the nodes in the node set are rebooted at the same time. Verify that the openstack-edpm-ipam-reboot deployment completed: If the deployment fails, see Troubleshooting data plane creation and deployment in the Deploying Red Hat OpenStack Services on OpenShift guide. Re-enable the Compute node: USD oc rsh openstackclient -n openstack USD openstack compute service set <hostname> nova-compute --enable Check that the Compute node is enabled: USD openstack compute service list

Commands:
oc logs jobs/reboot-os-<deployment_name>-<nodeSet_name>
oc rsh -n openstack openstackclient
openstack compute service list
openstack compute service set <hostname> nova-compute --disable
openstack server list --host <hostname> --all-projects
openstack server migrate --live-migration --host <target_host> --wait <instance_id>
openstack server list --host <hostname> --all-projects
exit
apiVersion: dataplane.openstack.org/v1beta1 kind: OpenStackDataPlaneDeployment metadata: name: openstack-edpm-ipam-reboot namespace: openstack spec: nodeSets: 1 - <nodeSet_name> servicesOverride: 2 - reboot-os ansibleExtraVars: 3 edpm_reboot_strategy: force ansibleLimit: <node_hostname>,...,<node_hostname> 4
oc get openstackdataplanedeployment NAME STATUS MESSAGE openstack-edpm-deployment-ipam-reboot True Setup complete
oc rsh openstackclient -n openstack openstack compute service set <hostname> nova-compute --enable
openstack compute service list