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Magnum must be stopped for upgrades, and can thus be performed on all magnum-hosts at the same time. It might be an idea to keep one set of hosts stopped at old code in case of the need for a sudden roll-back.

1. Reinstall the server to CentOS 8
2. Stop all magnum-services by adding the following keys to node-specific hiera, and then make sure to run puppet on the magnum hosts:

   1. magnum::conductor::enabled: false

   2. apache::service_ensure: 'stopped'

3. Run puppet with the ussuri modules/tags

4. Run yum upgrade

5. Run su -s /bin/sh -c "magnum-db-manage upgrade" magnum

6. Re-start magnum services by removing the keys added in step 1 and re-run puppet.

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1. Stop all magnum-services by adding the following keys to node-specific hiera, and then make sure to run puppet on the magnum hosts:

   1. octavia::housekeeping::enabled: false

   2. octavia::health_manager::enabled: false

   3. octavia::api::enabled: false

   4. octavia::worker::enabled: false

2. Run puppet with the ussuri modules/tags

3. Run apt-get dist-upgrade && apt-get autoremove

4. Run puppet

5. Run octavia-db-manage upgrade head


6. Re-start octavia services by removing the keys added in step 1 and re-run puppet.

7. Build a ussuri-based octavia-image and upload to glance. Tag it and make octavia start to replace the amphora.

Horizon

1. Reinstall the server to CentOS 8
2. Run puppet with the ussuri modules/tags
3. run yum upgrade

4. Run puppet again
5. restart httpd

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1. Run puppet with the ussuri modules/tags
2. Run apt-get purge python-cinderclient && apt dist-upgrade && apt-get autoremove
3. Run puppet again
4. Restart openstack services and openvswitch-services
   1. No downtime: systemctl restart nova-compute.service neutron-openvswitch-agent.service
   2. At a later point: reboot

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1. Reboot the compute-node

GPU-nodes

1. Reinstall the server to CentOS 8
2. Run puppet with the ussuri modules/tags
3. Run yum upgrade && yum autoremove
4. Run puppet again
5. Restart openstack services and openvswitch-services

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