# Migrate Cluster from VKS to VKS
To migrate a Cluster from the VKS system to the VKS system, follow the steps in this document.
### Prerequisites
* **Perform download helper bash script and grand execute permission for this file** ([ velero\_helper.sh](https://raw.githubusercontent.com/vngcloud/velero/main/velero_helper.sh) )
* (Optional) Deploy some services to check the correctness of the migration. Suppose, at the source Cluster, I have deployed an nginx service as follows:
* Deployment files:
```
apiVersion: v1
kind: Service
metadata:
name: nginx
namespace: mynamespace
labels:
app: nginx
spec:
ports:
- port: 80
name: web
selector:
app: nginx
type: NodePort
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: web
namespace: mynamespace
spec:
selector:
matchLabels:
app: nginx
serviceName: "nginx"
replicas: 1
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx
ports:
- containerPort: 80
name: web
volumeMounts:
- name: disk-ssd
mountPath: /usr/share/nginx/html
volumeClaimTemplates:
- metadata:
name: disk-ssd
namespace: mynamespace
spec:
accessModes: [ "ReadWriteOnce" ]
storageClassName: ssd-3000
resources:
requests:
storage: 40Gi
```
Copy
```
kubectl exec -n mynamespace -it web-0 bash
cd /usr/share/nginx/html
echo -e "\n\n MyGreenNode\n\n\n Hello, MyGreenNode
\n\n" > index.html
```
* Now, when you access Node's Public IP, you will see "Hello, MyGreenNode".
***
### Prepare target cluster (Prepare target resource)
On the VKS system, you need to initialize a Cluster according to the instructions [here](https://docs-vngcloud-vn.translate.goog/vng-cloud-document/v/vn/vks/clusters) . Make sure that the destination cluster's configuration is the same as the source cluster's configuration.
{% hint style="info" %}
**Attention:**
For the migration to be successful, on the target Cluster, you need to ensure the following requirements:
* The amount of resources needed such as number of nodes, node instance configuration,...
* Node labels and node taints are the same as the old cluster.
* Corresponding or alternative Storage Class.
{% endhint %}
***
### \[Optional] Migrate private resources outside cluster
Migrating private resources outside cluster (moving private resources outside the cluster) is the process of moving private resources outside the source Cluster to a place that the destination Cluster can use. For example, you may have private resources such as images, databases, etc. Now, before starting to migrate, you need to migrate these resources yourself. For example, if you need:
* Migrate Container Images: you can migrate images to GreenNode Container Registry through instructions [here](https://docs-vngcloud-vn.translate.goog/vng-cloud-document/v/vn/vcontainer-registry) .
* Migrate Databases: you can use **Relational Database Service (RDS)** and **Object Storage Service (OBS)** depending on your needs. After the migration is complete, remember to reconfigure the database for your applications on VKS Cluster.
* Migrate Storage: you can use vServer's **NFS Server** .
{% hint style="info" %}
**Attention:**
* After you migrate resources outside the Cluster, you need to ensure the target Cluster can connect to these migrated resources.
{% endhint %}
***
### Install Velero on both source and destination clusters (Install Velero tool)
After you have migrated private resources outside the cluster, you can use the migration tool to backup and restore the application on the source cluster and target cluster.
* Create a **vStorage Project, Container** to receive the cluster's backup data according to instructions [here](https://docs-vngcloud-vn.translate.goog/vng-cloud-document/v/vn/vstorage/object-storage/vstorage-hcm03/cac-tinh-nang-cua-vstorage/lam-viec-voi-project/khoi-tao-project) .
* Create an S3 key corresponding to this vStorage Project according to the instructions [here](https://docs-vngcloud-vn.translate.goog/vng-cloud-document/v/vn/vstorage/object-storage/vstorage-hcm03/quan-ly-truy-cap/quan-ly-tai-khoan-truy-cap-vstorage/tai-khoan-service-account/khoi-tao-vstorage-credentials/khoi-tao-s3-key) .
For example, I have initialized a vStorage Project, Container with the following information: Region: HCM03, Container: mycontainer, Endpoint: [https://hcm03.vstorage.vngcloud.vn](https://hcm03.vstorage.vngcloud.vn/) .
#### On both Clusters (source and target)
* Create file **credentials-velero** with the following content:
```
[default]
aws_access_key_id=________________________
aws_secret_access_key=________________________
```
* Install Velero CLI:
```
curl -OL https://github.com/vmware-tanzu/velero/releases/download/v1.13.2/velero-v1.13.2-linux-amd64.tar.gz
tar -xvf velero-v1.13.2-linux-amd64.tar.gz
cp velero-v1.13.2-linux-amd64/velero /usr/local/bin
```
* Install Velero on your 2 clusters with the command:
```
velero install --provider aws \
--plugins velero/velero-plugin-for-aws:v1.9.0,velero/velero-plugin-for-csi:v0.7.0 \
--secret-file ./credentials-velero \
--bucket ________________________ \
--backup-location-config region=hcm03,s3ForcePathStyle="true",s3Url=https://hcm03.vstorage.vngcloud.vn \
--use-node-agent \
--features=EnableCSI
```
```
velero client config set features=EnableCSI
```
{% hint style="info" %}
**Attention:**
* When you perform a cluster migration from VKS to VKS, we recommend that you use **Snapshot** to migrate your Volume from the source cluster to the destination cluster.
{% endhint %}
* Install the **GreenNode Snapshot Controller** plugin on 2 clusters with the command:
Copy
```
helm repo add vks-helm-charts https://vngcloud.github.io/vks-helm-charts
helm repo update
helm install vngcloud-snapshot-controller vks-helm-charts/vngcloud-snapshot-controller \
--replace --namespace kube-system
```
***
### At the source Cluster
* Annotate the Persistent Volumes that need to be backed up. By default, Velero will not backup volume. You can run the command below to annotate backup of all volumes.
```
./velero_helper.sh mark_volume -c
```
* Additionally, you can mark not to backup system resources with the following command:
```
./velero_helper.sh mark_exclude -c
```
* Apply the file below to create the default VolumeSnapshotClass:
```
apiVersion: snapshot.storage.k8s.io/v1
kind: VolumeSnapshotClass
metadata:
name: vngcloud-vsclass
labels:
velero.io/csi-volumesnapshot-class: "true"
driver: bs.csi.vngcloud.vn
deletionPolicy: Delete
# user can choose the VolumeSnapshotClass by setting annotation velero.io/csi-volumesnapshot-class_disk.csi.cloud.com: "test-snapclass" on backup resource.
# user can choose the VolumeSnapshotClass by setting annotation velero.io/csi-volumesnapshot-class: "test-snapclass" on PersistentVolumeClaim resource.
```
* Perform backup according to the syntax:
```
velero backup create vks-full-backup \
--exclude-namespaces velero \
--include-cluster-resources=true \
--wait
```
```
velero backup describe vks-full-backup --details
```
***
### At the destination Cluster
* Perform restore according to the command:
```
velero restore create --from-backup vks-full-backup \
--exclude-resources="MutatingWebhookConfiguration,ValidatingWebhookConfiguration"
```
```
velero restore create --from-backup vks-full-backup
```
---
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