docs(k8s): add warning to documentation (#5725)

* docs(k8s): add warning to documentation * fix(k8s): close message

Author: bene2k1

pages/kubernetes/how-to/upgrade-kapsule-new-node-image-system.mdx

@@ -3,7 +3,7 @@ title: How to upgrade a Kapsule cluster to the new node image system
 description: Learn how to upgrade a Kapsule cluster to the new node image system.
 tags: kubernetes kapsule node image
 dates:
- validation: 2025-09-04
+ validation: 2025-10-28
  posted: 2025-09-04
 categories:
  - containers
@@ -17,7 +17,7 @@ Upgrades will also be faster, as nodes will be replaced instead of rebooted.
 
 ## Technical specifications of the upgrade process
 
-* **Node replacement**: During upgrade, nodes will be replaced with new ones, which may have implications for data stored locally on nodes (e.g., `hostPath`). Data stored in persistent volumes (PV) will not be affected.
+* **Node replacement**: During upgrade, nodes will be replaced with new ones, **any local data will be lost**. Data stored in Persistent Volumes (PV) will not be affected.
 * **New IP addresses**: The new replacement nodes will have new IP addresses (both public and private), which could impact IP filtering configurations.
 * **GPU pool upgrade**: The upgrade of GPU pools may result in a partial downtime due to a limitation in the GPU operator, which cannot handle mixed Ubuntu versions (22.04 vs 24.04). The operator will install incorrect drivers on new nodes until the upgrade is complete, after which it will recover automatically.
 
@@ -30,6 +30,12 @@ Upgrades will also be faster, as nodes will be replaced instead of rebooted.
 
 You can upgrade your Scaleway Kubernetes Kapsule cluster to the new image system using either the console or the CLI.
 
+<Message type="important">
+ During the upgrade process, all cluster nodes will be replaced with new ones.
+ Any data stored locally on the nodes (for example, using `hostPath`) will be **permanently lost**.
+ Data stored in **Persistent Volumes (PVs)** will **not** be affected.
+</Message>
+
 ### Console upgrade
 
 1. Navigate to **Kubernetes** under the **Containers** section of the [Scaleway console](https://console.scaleway.com/) side menu. The Kubernetes dashboard displays.
@@ -48,5 +54,5 @@ Example of commands:
  ```
 * Migrate a specific pool of a cluster to new images:
  ```
- scw k8s pool migrate-to-new-images cluster-id=11111111-1111-1111-1111-111111111111 pools.0=22222222-2222-2222-2222-222222222222
+ scw k8s pool migrate-to-new-images cluster-id=11111111-1111-1111-1111-111111111111 pools-ids.0=22222222-2222-2222-2222-222222222222
  ```