Merge pull request #250743 from MGoedtel/task154633

updated azure-files-csi

Author: prmerger-automator[bot]

articles/aks/azure-files-csi.md

@@ -3,7 +3,7 @@ title: Use Container Storage Interface (CSI) driver for Azure Files on Azure Kub
 description: Learn how to use the Container Storage Interface (CSI) driver for Azure Files in an Azure Kubernetes Service (AKS) cluster.
 ms.topic: article
 ms.custom: devx-track-linux
-ms.date: 04/19/2023
+ms.date: 09/12/2023
 ---
 
 # Use Azure Files Container Storage Interface (CSI) driver in Azure Kubernetes Service (AKS)
@@ -313,6 +313,33 @@ This option is optimized for random access workloads with in-place data updates
 > [!NOTE]
 > You can use a private endpoint instead of allowing access to the selected VNet.
 
+### Optimizing read and write size options
+
+This section provides information about how to approach performance tuning NFS with the Azure Files CSI driver with the *rsize* and *wsize* options. The rsize and wsize options set the maximum transfer size of an NFS operation. If rsize or wsize are not specified on mount, the client and server negotiate the largest size supported by the two. Currently, both Azure NetApp Files and modern Linux distributions support read and write sizes as large as 1,048,576 Bytes (1 MiB).
+
+Optimal performance is based on efficient client-server communication. Increasing or decreasing the **mount** read and write option size values can improve NFS performance. The default size of the read/write packets transferred between client and server are 8 KB for NFS version 2, and 32 KB for NFS version 3 and 4. These defaults may be too large or too small. Reducing the rsize and wsize might improve NFS performance in a congested network by sending smaller packets for each NFS-read reply and write request. However, this can increase the number of packets needed to send data across the network, increasing total network traffic and CPU utilization on the client and server.
+
+It's important that you perform testing to find an rsize and wsize that sustains efficent packet transfer, where it doesn't decrease throughput and increase latency.
+
+For more information on optimizing rsize and wsize, see [Linux NFS mount options best practices for Azure NetApp Files][azure-netapp-files-mount-options-best-practices].
+
+For example, to configure a maximum *rsize* and *wsize* of 256-KiB, configure the `mountOptions` in the storage class as follows:
+
+```yml
+apiVersion: storage.k8s.io/v1
+kind: StorageClass
+metadata:
+  name: azurefile-csi-nfs
+provisioner: file.csi.azure.com
+allowVolumeExpansion: true
+parameters:
+  protocol: nfs
+mountOptions:
+  - nconnect=4
+  - rsize=262144
+  - wsize=262144
+```
+
 ### Create NFS file share storage class
 
 Create a file named `nfs-sc.yaml` and copy the manifest below.
@@ -481,3 +508,4 @@ The output of the commands resembles the following example:
 [tag-resources]: ../azure-resource-manager/management/tag-resources.md
 [statically-provision-a-volume]: azure-csi-files-storage-provision.md#statically-provision-a-volume
 [azure-private-endpoint-dns]: ../private-link/private-endpoint-dns.md#azure-services-dns-zone-configuration
+[azure-netapp-files-mount-options-best-practices]: ../azure-netapp-files/performance-linux-mount-options.md#rsize-and-wsize