feat(k8s): add documentation for etcd quotas (#3515)

containers/kubernetes/reference-content/kubernetes-control-plane-offers.mdx

@@ -7,7 +7,7 @@ content:
   paragraph: This page provides information about the different control plane offers available for Scaleway Kubernetes Kapsule and Kosmos
 tags: kubernetes control plane control-plane offers dedicated mutualized
 dates:
-  validation: 2024-04-03
+  validation: 2024-08-22
   posted: 2023-09-26
 categories:
   - kubernetes
@@ -34,10 +34,13 @@ Whether you are seeking a mutualized environment or a dedicated control plane, w
 | SLA                | N/A                       | 99.5% uptime      | 99.5% uptime      | 99.5% uptime       |
 | Audit logs         | N/A                       | Enabled      | Enabled      | Enabled       |
 | Max cluster size   | 150 nodes                 | 250 nodes         | 500 nodes         | 500 nodes          |
+| Max etcd size      | 55 MB                     | 2OO MB            | 200 MB            | 200 MB             |
+
 
 <Message type="note">
   * <sup>1</sup> Each mutualized control plane can use up to 4 GB memory (RAM and swap).
   * The resource quotas for each offer are subject to potential evolutions over time, and this table will be modified accordingly.
+  * The size of the etcd key value store is limited to 55 MB and 200 MB, for mutualized and dedicated control planes, respectively. You can view the usage of your control plane’s etcd in Cockpit.
 </Message>
 
 <Lightbox src="scaleway-dcp-detailed.webp" alt="Schema Scaleway Dedicated control planes for Kubernetes" size="large" />
@@ -62,6 +65,24 @@ Once a dedicated control plane is no longer under commitment, you can freely mig
 
 If a dedicated cluster is deleted, the commitment is automatically canceled, and there will be no further billing for this dedicated service.
 
+## etcd size limitation on Scaleway managed Kubernetes products
+
+In Scaleway's managed Kubernetes offers, the size of the etcd key-value store is a critical factor that users must consider.
+The etcd store is the backbone of Kubernetes, holding all cluster data and ensuring the smooth operation of the control plane. However, there are size limitations to be aware of:
+
+- **Mutualized control planes**: The etcd size is limited to 55 MB.
+- **Dedicated control planes**: The etcd size is increased to 200 MB.
+
+These limitations exist to ensure the stability and performance of your Kubernetes clusters.
+
+For users running complex applications or managing large volumes of data, opting for a dedicated control plane is advisable. This not only provides a more substantial etcd quota but also enhances overall cluster performance and reliability. 
+
+You can monitor the size of your control plane’s etcd using [Cockpit](/observability/cockpit/quickstart/), Scaleway’s intuitive management interface. This visibility helps in proactive management and ensures you remain within the allotted limits, avoiding potential disruptions.
+
+<Message type="note">
+  You can not downgrade your cluster's control plane from a dedicated one to a mutualized control plane when your etcd quota exceeds the mutualized storage allowance.
+</Message>
+
 ## Changing a control plane offer
 
 During the lifecycle of a Kubernetes cluster, you have the flexibility to transition its control plane to a different type, whether it involves [scaling up or scaling down](/faq/kubernetes/#can-i-change-the-plan-of-my-cluster's-control-plane), to align with their specific workloads.