Chapter 12. Configuring manual node reboot to define KernelArgs

Procedure

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

2. Source the stackrc file:

   [stack@director ~]$ source ~/stackrc

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3. Enable the KernelArgsDeferReboot role parameter in a custom environment file, for example, kernelargs_manual_reboot.yaml:

   parameter_defaults:
     <Role>Parameters:
       KernelArgsDeferReboot: True

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4. Add your custom environment file to the stack with your other environment files and deploy the overcloud:

   (undercloud)$ openstack overcloud deploy --templates \
    -e [your environment files] \
    -e /home/stack/templates/kernelargs_manual_reboot.yaml

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5. Retrieve a list of your Compute nodes to identify the host name of the node that you want to reboot:

   (undercloud)$ source ~/overcloudrc
   (overcloud)$ openstack compute service list

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6. Disable the Compute service on the Compute node you want to reboot, to prevent the Compute scheduler from assigning new instances to the node:

   (overcloud)$ openstack compute service set <node> nova-compute --disable

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   Replace <node> with the host name of the node you want to disable the Compute service on.

7. Retrieve a list of the instances hosted on the Compute node that you want to migrate:

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

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8. Migrate the instances to another Compute node. For information on migrating instances, see Migrating virtual machine instances between Compute nodes.
9. Log in to the node that you want to reboot.

10. Reboot the node:

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

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11. Wait until the node boots.

12. Re-enable the Compute node:

    (overcloud)$ openstack compute service set <node_UUID>  nova-compute --enable

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13. Check that the Compute node is enabled:

    (overcloud)$ openstack compute service list

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