Rehome a Subcloud¶

When the System Controller needs to be reinstalled, or when the subclouds from multiple System Controllers are being consolidated into a single System Controller, you can add already deployed subclouds to a different System Controller using the rehoming playbook.

Note

The rehoming playbook does not work with freshly installed/bootstrapped subclouds.

Note

The system time should be accurately configured on the System Controllers and the subcloud’s controllers before rehoming the subcloud.

Note

The system controllers and subclouds must run the same software versions.

Warning

Do not rehome a subcloud if the RECONCILED status on the system resource or any host resource of the subcloud is FALSE. To check the RECONCILED status, run the kubectl -n deployment get system and kubectl -n deployment get hosts commands.

Use the following procedure to enable subcloud rehoming and to update the new subcloud configuration (networking parameters, passwords, etc.) to be compatible with the new System Controller.

About this task

There are six phases for Rehoming a subcloud:

Unmanage the subcloud from the previous System Controller.

Note

You can skip this phase if the previous System Controller is no longer running or is unable to connect to the subcloud.
Update the admin password on the subcloud to match the new System Controller, if required.
Run the subcloud add command with the --migrate option on the new System Controller. This will update the System Controller and connect to the subcloud to update the appropriate configuration parameters.
On the subcloud, lock/unlock the subcloud controller(s) to enable the new configuration.
Use the dcmanager subcloud list command to check the status of the subcloud, ensure the subcloud is online and complete before managing the subcloud.
On the new System Controller, set the subcloud to “managed” and wait for it to sync.

Prerequisites

Ensure that the subcloud management subnet, oam_floating_address, oam_node_0_address and oam_node_1_address (if applicable) does not overlap addresses already being used by the new System Controller or any of its subclouds.
Ensure that the subcloud has been backed up, in case something goes wrong and a subcloud system recovery is required.
Transfer the yaml file that was used to bootstrap the subcloud prior to rehoming, to the new System Controller. This data is required for rehoming.
If the subcloud can be remotely installed via Redfish Virtual Media service, transfer the yaml file that contains the install data for this subcloud, and use this install data in the new System Controller, via the --install-values option, when running the remote subcloud reinstall, upgrade or restore commands.

Note

These prerequisites apply if the old System Controller is still available.

Procedure

If the previous System Controller is running, use the following command to ensure that it does not try to change subcloud configuration while you are modifying it to be compatible with the new System Controller.
```
~(keystone_admin)]$ dcmanager subcloud unmanage <subcloud_name>
```
Ensure that the subcloud’s bootstrap values file is available on the new System Controller. If required, in the subcloud’s bootstrap values file update the systemcontroller_gateway_address entry to point to the appropriate network gateway for the new System Controller to communicate with the subcloud.
If the admin password of the subcloud does not match the admin password of the new System Controller, use the following command to change the subcloud admin password. This step is done on the subcloud that is being migrated.
```
~(keystone_admin)]$ openstack user password set
```
Note

You will need to specify the old and the new password.
For an AIO-DX subcloud, ensure that the active controller is controller-0. Perform a host-swact of the active controller (controller-1) to make controller-0 active.
```
~(keystone_admin)]$ system host-swact controller-1
```

Lock controller-1 of the subcloud.

~(keystone_admin)]$ system host-lock controller-1

On the new System Controller, use the following command to start the rehoming process.
```
~(keystone_admin)]$ dcmanager subcloud add --migrate --bootstrap-address <subcloud-controller-0-oam-address> --bootstrap-values <bootstrap_values_file> [--install-values <install_values_file>]
```
Note

You will need to update the systemcontroller_gateway_address variable in the bootstrap values file before you perform the migration. This field is the gateway address to the new System Controller.

The subcloud deploy status will change to “pre-rehome” and if the preliminary steps complete successfully it will change to “rehoming”. At this point an Ansible playbook will run and update the appropriate configuration data in the subcloud. You can query the status by running dcmanager subcloud show command. Once the subcloud has been updated, the subcloud deploy status will change to “complete”.

Note

The --install-values parameter is optional and is not mandatory for subcloud rehoming. However, you can opt to save these values on the new System Controller as part of the rehoming process so that future operations that involve remote reinstallation of the subcloud (e.g. reinstall, upgrade, restore) can be performed for the rehomed subcloud.

The subcloud install values can also be added to or updated on the new System Controller using the dcmanager subcloud update --install-values command post subcloud rehoming.

Delete the “image:” line from the install-values file, if it exists, so that the image is correctly located based on the new System Controller configuration.
If the previous System Controller is still running, delete the subcloud after it goes offline, using the following command.
```
~(keystone_admin)]$ dcmanager subcloud delete <subcloud-name>
```
For an AIO-SX subcloud, use the following commands to lock/unlock the controller (wait for the lock to complete before unlocking the controller).
```
~(keystone_admin)]$ system host-lock controller-0
~(keystone_admin)]$ system host-unlock controller-0
```
For an AIO-DX subcloud, first, use the following command to unlock controller-1.
```
~(keystone_admin)]$ system host-unlock controller-1
```
1. Wait until controller-1 is unlocked/online/available, then use the following command to switch activity to controller-1.
```
~(keystone_admin)]$ system host-swact controller-0
```
2. After the swact is complete, use the following commands to lock/unlock controller-0.
```
~(keystone_admin)]$ system host-lock controller-0
~(keystone_admin)]$ system host-unlock controller-0
```
3. Wait until controller-0 is unlocked/online/available, then switch activity back to controller-0.
4. Perform a swact on controller-1.
```
~(keystone_admin)]$ system host-swact controller-1
```
  Wait until the swact is complete.

Use the dcmanager subcloud list command to display the status of the subcloud, and ensure the subcloud is online and complete before managing the subcloud.

~(keystone_admin)]$ dcmanager subcloud list

+----+-----------+------------+--------------+---------------+---------+
| id | name      | management | availability | deploy status | sync    |
+----+-----------+------------+--------------+---------------+---------+
|  1 | subcloud1 | unmanaged  | online       | complete      | unknown |
+----+-----------+------------+--------------+---------------+---------+

Use the following command to “manage” the subcloud. This is executed on the System Controller.
```
~(keystone_admin)]$ dcmanager subcloud manage <subcloud-name>
```
The new System Controller will audit the subcloud and determine whether it is in-sync with the System Controller.

Error Recovery

If the subcloud rehoming process begins successfully, (status changes to “rehoming”) but there is a transient fault that prevents step 5 from completing successfully, then manual error recovery is required.

The first stage of error recovery is to delete the subcloud from the new System Controller and re-attempt rehoming using the following commands:

~(keystone_admin)]$ dcmanager subcloud delete <subcloud-name>
~(keystone_admin)]$ dcmanager subcloud add --migrate --bootstrap-address <subcloud-controller-0-oam-address> --bootstrap-values <bootstrap_values_file> [--install-values <install_values_file>]

If all attempts fail, restore the subcloud from backups, that will revert the subcloud to the original state prior to rehoming.

Rehome a Subcloud

Rehome a Subcloud¶

StarlingX R6.0