7.4. Removing a Compute node from the data plane

Procedure

1. Access the remote shell for the openstackclient pod:

   $ oc rsh -n openstack openstackclient

2. Retrieve the IP address of the Compute node that you want to remove:

   $ openstack hypervisor list

3. Retrieve a list of your Compute nodes to identify the name and UUID of the node that you want to remove:

   $ openstack compute service list

4. Disable the nova-compute service on the Compute node to be removed:

   $ openstack compute service set <hostname> nova-compute --disable

   작은 정보

   Use the --disable-reason option to add a short explanation on why the service is being disabled. This is useful if you intend to redeploy the Compute service.

5. Exit the OpenStackClient pod:

   $ exit

6. SSH into the Compute node to be removed and stop the ovn and nova-compute containers:

   $ ssh -i <key_file_name> cloud-admin@<node_IP_address>
   [cloud-admin@<hostname> ~]$ sudo systemctl stop edpm_ovn_controller
   [cloud-admin@<hostname> ~]$ sudo systemctl stop edpm_ovn_metadata_agent
   [cloud-admin@<hostname> ~]$ sudo systemctl stop edpm_nova_compute

   • Replace <key_file_name> with the name and location of the SSH key pair file you created to enable Ansible to manage the RHEL nodes.
   • Replace <node_IP_address> with the IP address for the Compute node that you retrieved in step 2.

7. Remove the systemd unit files that manage the ovn and nova-compute containers to prevent the agents from being automatically started and registered in the database if the removed node is rebooted:

   [cloud-admin@<hostname> ~]$ sudo rm -f /etc/systemd/system/edpm_ovn_controller
   [cloud-admin@<hostname> ~]$ sudo rm -f /etc/systemd/system/edpm_ovn_metadata_agent
   [cloud-admin@<hostname> ~]$ sudo rm -f /etc/systemd/system/edpm_nova_compute

8. Disconnect from the Compute node:

   $ exit

9. Access the remote shell for openstackclient:

   $ oc rsh -n openstack openstackclient

10. Delete the network agents for the Compute node to be removed:

    $ openstack network agent list [--host <hostname>]
    $ openstack network agent delete <agent_id>

11. Delete the nova-compute service for the Compute node to be removed:

    $ openstack compute service delete <node_uuid>

    • Replace <node_uuid> with the UUID of the node to be removed that you retrieved in step 3.

12. Exit the OpenStackClient pod:

    $ exit

13. Remove the node from the OpenStackDataPlaneNodeSet CR:

    $ oc patch openstackdataplanenodeset/<node_set_name> --type json --patch '[{ "op": "remove", "path": "/spec/nodes/<node_name>" }]'

    • Replace <node_set_name> with the name of the OpenStackDataPlaneNodeSet CR that the node belongs to.
    • Replace <node_name> with the name of the node defined in the nodes section of the OpenStackDataPlaneNodeSet CR.

14. Create a file on your workstation to define the OpenStackDataPlaneDeployment CR to update the node set with the Compute node removed:

    apiVersion: dataplane.openstack.org/v1beta1
    kind: OpenStackDataPlaneDeployment
    metadata:
      name: <node_set_deployment_name>

    • Replace <node_set_deployment_name> with the name of the OpenStackDataPlaneDeployment CR. The name must be unique, must consist of lower case alphanumeric characters, - (hyphen) or . (period), and must start and end with an alphanumeric character.
    작은 정보

    Give the definition file and the OpenStackDataPlaneDeployment CR unique and descriptive names that indicate the purpose of the modified node set.

15. Add the OpenStackDataPlaneNodeSet CR that you removed the node from:

    spec:
      nodeSets:
        - <nodeSet_name>

16. Save the OpenStackDataPlaneDeployment CR deployment file.

17. Deploy the OpenStackDataPlaneDeployment CR to delete the removed nodes:

    $ oc create -f openstack_data_plane_deploy.yaml -n openstack

    You can view the Ansible logs while the deployment executes:

    $ oc get pod -l app=openstackansibleee -w
    $ oc logs -l app=openstackansibleee -f --max-log-requests 10

    If the oc logs command returns an error similar to the following error, increase the --max-log-requests value:

    error: you are attempting to follow 19 log streams, but maximum allowed concurrency is 10, use --max-log-requests to increase the limit

18. Verify that the modified OpenStackDataPlaneNodeSet CR is deployed:

    $ oc get openstackdataplanedeployment -n openstack
    NAME                  NODESETS                  STATUS  MESSAGE
    openstack-data-plane  ["openstack-data-plane"]  True    Setup Complete
    
    $ oc get openstackdataplanenodeset -n openstack
    NAME                  STATUS  MESSAGE
    openstack-data-plane  True    NodeSet Ready

    For information about the meaning of the returned status, see Data plane conditions and states in Deploying Red Hat OpenStack Services on OpenShift.

    If the status indicates that the data plane has not been deployed, then troubleshoot the deployment. For information, see Troubleshooting the data plane creation and deployment in Deploying Red Hat OpenStack Services on OpenShift.