Draft of new article

Author: johnmarco

articles/openshift/howto-large-clusters.md

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+---
+title: Deploy a large Azure Red Hat OpenShift cluster
+description: Discover how to deploy a large Azure Red Hat OpenShift cluster.
+author: johnmarco
+ms.author: johnmarc
+ms.service: azure-redhat-openshift
+ms.topic: article
+ms.date: 07/05/2024
+---
+# Deploy a large Azure Red Hat OpenShift cluster
+
+This article provides the steps and best practices for deploying large scale Azure Red Hat OpenShift clusters up to 180 nodes. For clusters of that size, a combination of control plane nodes and infrastructure nodes to ensure the cluster functions properly.
+
+## Deploy a cluster
+
+For clusters with over 101 nodes, use the following [virtual machine instance types](support-policies-v4.md#supported-virtual-machine-sizes) size recommendations (or similar, newer generation instance types):
+
+- Standard_D32s_v3
+- Standard_D32s_v4
+- Standard_D32s_v5
+
+Following is a sample script using Azure CLI to deploy a cluster with Standard_D32s_v5 as the control plane nodes:
+
+```azurecli
+#az aro create \ --resource-group $RESOURCEGROUP \ --name $CLUSTER \ --vnet aro-vnet \ --master-subnet master-subnet \ --worker-subnet worker-subnet --master-vm-size Standard_D32s_v5
+```
+
+## Deploy infrastructure nodes for the cluster
+
+For clusters with over 101 nodes, infrastructure nodes are required to separate cluster workloads (such as prometheus) to minimize contention with other workloads.
+ 
+> [!NOTE]
+> It's recommended that you deploy 3 infrastructure nodes per cluster for redundancy and scalability needs. 
+> 
+
+The following instance types are recommended for infrastructure nodes:
+
+- Standard_E16as_v5
+- Standard_E16s_v5
+
+For instructions on configuring infrastructure nodes, see [Deploy infrastructure nodes in an Azure Red Hat OpenShift (ARO) cluster](howto-infrastructure-nodes.md).
+
+## Add IP addresses to the cluster
+
+A maximum of 20 IP addresses can be added to a load balancer. One (1) OP addresses is needed per 65 nodes, so a cluster with 180 nodes requires a minimum of three (3) IP addresses.
+
+To add IP addresses to the load balancer using Azure CLI, run the following:
+
+`az aro update -n [clustername] –g [resourcegroup]  --lb-ip-count 20`
+
+To add IP addresses through a rest API call:
+
+```rest
+az rest --method patch --url https://management.azure.com/subscriptions/fe16a035-e540-4ab7-80d9-373fa9a3d6ae/resourceGroups/shared-cluster/providers/Microsoft.RedHatOpenShift/OpenShiftClusters/shared-cluster?api-version=2023-07-01-preview --body '{"properties": {"networkProfile": {"loadBalancerProfile": {"managedOutboundIps": {"count": 5}}}}}' --headers "Content-Type=application/json"
+```
+

articles/openshift/toc.yml

@@ -32,6 +32,8 @@
           href: quickstart-openshift-arm-bicep-template.md
         - name: Upgrade an Azure Red Hat OpenShift cluster
           href: howto-upgrade.md
+        - name: Deploy large ARO clusters spot nodes
+          href: howto-large-clusters.md
         - name: Use spot nodes
           href: howto-spot-nodes.md
         - name: Deploy infrastructure nodes