Merge pull request #205099 from stl327/main

[AKS] Add Default OS Disk Sizing Feature

Author: PRMerger9

articles/aks/concepts-clusters-workloads.md

@@ -78,6 +78,8 @@ The Azure VM size for your nodes defines the storage CPUs, memory, size, and typ
 
 In AKS, the VM image for your cluster's nodes is based on Ubuntu Linux or Windows Server 2019. When you create an AKS cluster or scale out the number of nodes, the Azure platform automatically creates and configures the requested number of VMs. Agent nodes are billed as standard VMs, so any VM size discounts (including [Azure reservations][reservation-discounts]) are automatically applied.
 
+For managed disks, the default disk size and performance will be assigned according to the selected VM SKU and vCPU count. For more information, see [Default OS disk sizing](cluster-configuration.md#default-os-disk-sizing).
+
 If you need advanced configuration and control on your Kubernetes node container runtime and OS, you can deploy a self-managed cluster using [Cluster API Provider Azure][cluster-api-provider-azure].
 
 ### Resource reservations

articles/aks/operator-best-practices-storage.md

@@ -84,8 +84,13 @@ In this example, the *Standard_DS2_v2* offers twice as many attached disks, and
 
 Work with your application development team to understand their storage capacity and performance needs. Choose the appropriate VM size for the AKS nodes to meet or exceed their performance needs. Regularly baseline applications to adjust VM size as needed.
 
+> [!NOTE]
+> By default, disk size and performance for managed disks is assigned according to the selected VM SKU and vCPU count. Default OS disk sizing is only used on new clusters or node pools when Ephemeral OS disks are not supported and a default OS disk size is not specified. For more information, see [Default OS disk sizing](cluster-configuration.md#default-os-disk-sizing).
+
 For more information about available VM sizes, see [Sizes for Linux virtual machines in Azure][vm-sizes].
 
+
+
 ## Dynamically provision volumes
 
 > **Best practice guidance**