# OS Migration for SMCP 5.12

***

## **1. Run step 1-4 from**[ **this document**](https://platform9.com/docs/PEC/upgrade-smcp) **to take the appropriate backup from the cluster, along with etcd backup and cleanup the old cluster**

{% hint style="warning" %}
**RECOMMENDED**

Before cluster destruction, take the backup of ***`/etc/hosts`*** from the nodelet cluster node. Apply the changes once the management cluster is up.
{% endhint %}

* [Backup Current System](https://platform9.com/docs/PEC/upgrade-smcp#1-backup-current-system) : Take a fresh backup of the upgraded SMCP cluster (SMCP 5.12) and store it in a secure location.
* [Take etcd Snapshot](https://platform9.com/docs/PEC/upgrade-smcp#2-take-etcd-snapshot)
* [Destroy Old Cluster](https://platform9.com/docs/PEC/upgrade-smcp#3-destroy-old-cluster)
* [Clean Up Configuration](https://platform9.com/docs/PEC/upgrade-smcp#4-clean-up-configuration)

{% hint style="info" %}
**NOTE**

Take the backup of airctl-config.yaml and nodelet-bootstrap.yaml for references.
{% endhint %}

2. **Follow next two step from the SMCP installation guide to setup nodelet cluster on the the new OS host.**

* [Install Base Artifacts](https://platform9.com/docs/5.12/PEC/installation#install-base-artifacts)
* [Configuration](https://platform9.com/docs/5.12/PEC/installation#configuration)

{% hint style="info" %}
**NOTE**

Ensure the S3 DNS entry *`34.35.69.42 s3-us-west-1.amazonaws.com`* is added to the `nodelet-bootstrap.yaml`. Also, note that the `userImages:` section in the `nodelet-bootstrap.yaml` is not required.
{% endhint %}

{% tabs %}
{% tab title="nodelet-bootstrap.yaml" %}

```yaml
dns:
  corednsHosts:
  - 34.35.69.42 s3-us-west-1.amazonaws.com 
isAirgapped: true
systemImages:
- /opt/pf9/airctl/imgs/kubedu-imgs-v-5.12.1-3802903.tar.gz
- /opt/pf9/airctl/imgs/nodelet-imgs-v-5.12.1-3802903.tar.gz
```

{% endtab %}
{% endtabs %}

{% hint style="info" %}
**NOTE**

To enable passwordless access to the workload hosts from the DU, update the `~/.ssh/authorized_keys` file on all workload hosts with the public key from the nodelet hosts, if it has been changed
{% endhint %}

**3. Follow step 7-9 from** [**this document** ](https://platform9.com/docs/PEC/upgrade-smcp)**to create management cluster and restore the cluster.**

* [Deploy New Management Cluster](https://platform9.com/docs/PEC/upgrade-smcp#7-deploy-new-management-cluster)
* [Restore from Backup](https://platform9.com/docs/PEC/upgrade-smcp#8-restore-from-backup)
* [Verify DU Status](https://platform9.com/docs/PEC/upgrade-smcp#9-verify-du-status)

{% hint style="info" %}
**NOTE**

If the external IP of the nodelet cluster has changed, we need to update all the attached nodes with the new IP. Run the following command to update the `/etc/hosts` file without performing any package installation:
{% endhint %}

{% tabs %}
{% tab title="Bash" %}

```bash
/opt/pf9/airctl/airctl configure-hosts --skip-docker-img-import --skip-docker-install --skip-yum-repo-install --config /opt/pf9/airctl/conf/airctl-config.yaml
```

{% endtab %}
{% endtabs %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.platform9.com/self-managed-cloud-platform/5.13/sso-configuration/os-migration-for-smcp.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.