Merge pull request #3360 from anupras-mohapatra-arm/servers-and-cloud-computing

Longhorn for Kubernetes persistent storage on Azure documentation review

Author: jasonrandrews

content/learning-paths/servers-and-cloud-computing/longhorn-cobalt/_index.md

@@ -1,24 +1,20 @@
 ---
-title: Deploy Longhorn on Azure Cobalt 100 Arm64 virtual machines for Kubernetes persistent storage
-
-draft: true
-cascade:
-    draft: true
+title: Use Longhorn to deploy persistent storage for Kubernetes workloads on Arm-based Azure virtual machines
 
-description: Learn how to install and configure Longhorn on an Azure Cobalt 100 Arm64 virtual machine, deploy Kubernetes persistent storage using K3s, create Persistent Volumes, and benchmark storage performance for cloud-native workloads.
+description: Learn how to install and configure Longhorn on an Arm64 Azure virtual machine powered by Azure Cobalt 100, deploy Kubernetes persistent storage using Longhorn on K3s, create persistent volumes, and benchmark storage performance for cloud-native workloads.
 
 minutes_to_complete: 60
 
 who_is_this_for: This is an introductory topic for developers, DevOps engineers, platform engineers, and Kubernetes administrators who want to deploy persistent storage for Kubernetes workloads using Longhorn on Arm-based cloud infrastructure.
 
 learning_objectives:
-    - Install and configure K3s Kubernetes on Azure Cobalt 100 Arm64 virtual machines
-    - Deploy and configure Longhorn distributed block storage on Arm64
-    - Create and manage Kubernetes Persistent Volumes using Longhorn
+    - Install and configure K3s Kubernetes on an Arm64 Azure virtual machine powered by Azure Cobalt 100
+    - Install and configure Longhorn distributed block storage on Arm64
+    - Create and manage Kubernetes persistent volumes using Longhorn
     - Benchmark Kubernetes storage performance using fio
 
 prerequisites:
-  - A [Microsoft Azure account](https://azure.microsoft.com/) with access to Cobalt 100 based instances (Dpsv6)
+  - A [Microsoft Azure account](https://azure.microsoft.com/) with access to Cobalt 100-based instances (Dpsv6)
   - Basic knowledge of Linux command-line operations
   - Familiarity with SSH and remote server access
   - Basic understanding of Kubernetes and containerized workloads

content/learning-paths/servers-and-cloud-computing/longhorn-cobalt/background.md

@@ -1,5 +1,6 @@
 ---
 title: Understand Longhorn on Azure Cobalt 100
+description: Understand how Longhorn provides Kubernetes persistent storage on Arm64 virtual machines powered by Azure Cobalt 100.
 
 weight: 2
 
@@ -8,52 +9,49 @@ layout: "learningpathall"
 
 ## Why run Longhorn on Azure Cobalt 100
 
-Longhorn on Arm-based Azure Cobalt 100 processors provides lightweight, Kubernetes-native distributed storage for cloud-native workloads running on Arm64 infrastructure.
+Longhorn on Arm-based Azure Cobalt 100 processors provides lightweight, Kubernetes-native, persistent distributed storage for cloud-native workloads running on Arm64 infrastructure.
 
-Azure Cobalt 100 processors deliver dedicated physical cores per vCPU, providing predictable and consistent performance for Kubernetes storage workloads. This architecture complements Longhorn’s distributed block storage model and helps deliver stable storage performance for stateful applications running on Kubernetes.
+Azure Cobalt 100 processors deliver dedicated physical cores per vCPU, providing predictable and consistent performance for Kubernetes storage workloads. This architecture complements Longhorn’s distributed block storage model and delivers stable storage performance for stateful applications running on Kubernetes.
 
-Longhorn enables persistent storage for Kubernetes workloads such as databases, analytics platforms, monitoring stacks, and stateful cloud-native applications running on Azure Cobalt 100 Arm64 virtual machines.
+You’ll use this architecture in the following sections to install Longhorn on K3s, create a Longhorn-backed PersistentVolume, and validate storage behavior with fio.
 
 ## Azure Cobalt 100 Arm-based processor
 
-Azure’s Cobalt 100 is Microsoft’s first-generation, in-house Arm-based processor. Built on Arm Neoverse N2, Cobalt 100 is a 64-bit CPU that delivers strong performance and energy efficiency for cloud-native, scale-out Linux workloads.
+Azure’s Cobalt 100 is Microsoft’s first-generation, in-house Arm-based processor. Built on Arm Neoverse N2, Cobalt 100 is a 64-bit CPU that delivers strong performance and energy efficiency for cloud-native, scale-out Linux workloads. 
 
 These workloads include:
-
 - Kubernetes platforms
 - Containerized applications
-- Open-source databases
+- Open-source databases 
 - Data analytics systems
 - Storage and caching platforms
 
 Running at 3.4 GHz, Cobalt 100 allocates a dedicated physical core for each vCPU, ensuring predictable and consistent workload performance.
 
 To learn more, see the Microsoft blog [Announcing the preview of new Azure VMs based on the Azure Cobalt 100 processor](https://techcommunity.microsoft.com/blog/azurecompute/announcing-the-preview-of-new-azure-vms-based-on-the-azure-cobalt-100-processor/4146353).
 
-## How Longhorn improves Kubernetes storage
+## How Longhorn provides Kubernetes storage
 
 Longhorn is an open-source cloud-native distributed block storage platform designed specifically for Kubernetes environments.
 
 It provides persistent storage volumes for Kubernetes workloads and enables applications to retain data independently of container or pod lifecycle events.
 
 Longhorn integrates directly with Kubernetes through the Container Storage Interface (CSI) and provides dynamic volume provisioning, storage management, and persistent storage capabilities for stateful workloads.
 
-To learn more, see the official [Longhorn documentation](https://longhorn.io/docs/).
-
 Longhorn provides several important capabilities for Kubernetes storage management:
 
-- Persistent Volumes: Dynamically provisions Kubernetes Persistent Volumes for stateful workloads.
-- Distributed Storage: Replicates and manages block storage volumes across Kubernetes nodes.
-- CSI Integration: Integrates natively with Kubernetes using the Container Storage Interface.
-- Snapshot and Backup Support: Supports volume snapshots and backup operations for Kubernetes workloads.
-- Stateful Workload Support: Enables databases, monitoring stacks, and analytics applications to run with persistent storage.
+- Persistent volumes: Dynamically provisions Kubernetes persistent volumes for stateful workloads.
+- Distributed storage: Replicates and manages block storage volumes across Kubernetes nodes.
+- CSI integration: Integrates natively with Kubernetes using CSI.
+- Snapshot and backup support: Supports volume snapshots and backup operations.
+- Stateful workload support: Enables databases, monitoring stacks, and analytics applications to run with persistent storage.
 
-Longhorn is widely used in Kubernetes environments to provide lightweight and reliable storage without requiring external SAN or NAS infrastructure.
+It's widely used in Kubernetes environments to provide lightweight and reliable storage without requiring external Storage Area Network (SAN) or Network Attached Storage (NAS) infrastructure.
 
-In this Learning Path, you'll deploy Longhorn on an Azure Cobalt 100 Arm64 virtual machine using K3s Kubernetes. You'll configure Longhorn for a single-node Kubernetes cluster, create Persistent Volumes, validate storage persistence, and benchmark storage performance using fio.
+To learn more about Longhorn, see the official [Longhorn documentation](https://longhorn.io/docs/).
 
 ## What you've learned and what's next
 
-You now understand why Azure Cobalt 100 and Longhorn are a strong combination for Kubernetes-native persistent storage on Arm64 infrastructure.
+You now understand why Azure Cobalt 100 and Longhorn are a strong combination for Kubernetes-native persistent storage on Arm64 infrastructure. You also learned about the Kubernetes storage management capabilities that Longhorn provides.
 
-Next, you'll configure Azure networking and firewall rules, install K3s Kubernetes, deploy Longhorn, and begin creating Persistent Volumes for Kubernetes workloads.
+Next, you'll create a virtual machine with Azure Cobalt 100.

content/learning-paths/servers-and-cloud-computing/longhorn-cobalt/firewall.md

@@ -1,5 +1,6 @@
 ---
-title: Allow access to the Longhorn Web UI on Azure
+title: Allow network access to the Longhorn Web UI on Azure
+description: Configure Azure Network Security Group inbound rules for Kubernetes API access, HTTP workloads, and the Longhorn web UI on an Arm64 Azure VM powered by Azure Cobalt 100.
 weight: 4
 
 ### FIXED, DO NOT MODIFY
@@ -8,18 +9,18 @@ layout: learningpathall
 
 ## Configure external traffic for Longhorn and Kubernetes
 
-To allow external traffic for the Longhorn Web UI and Kubernetes services on an Azure virtual machine, open the required ports in the Network Security Group (NSG). The NSG can be attached to the virtual machine's network interface or subnet.
+To allow external traffic for the Longhorn web UI and Kubernetes services on an Azure virtual machine (VM), open the required ports in the Network Security Group (NSG). The NSG can be attached to the VM's network interface or subnet.
 
 {{% notice Note %}}For more information about Azure setup, see [Getting started with Microsoft Azure Platform](/learning-paths/servers-and-cloud-computing/csp/azure/).{{% /notice %}}
 
 
 ### Add inbound firewall rules in Azure
 
-To expose the required TCP ports for Kubernetes and Longhorn, create an inbound firewall rule.
+To expose the required TCP ports for Kubernetes and Longhorn, create an inbound firewall rule:
 
-1. Navigate to the [Azure portal](https://portal.azure.com), go to **Virtual Machines**, and select your virtual machine.
+1. Navigate to the [Azure portal](https://portal.azure.com), go to **Virtual Machines**, and select your VM.
 
-![Azure Portal Virtual Machines page with the target VM selected. Verify that the correct Azure Cobalt 100 virtual machine is selected before configuring network access.#center](images/virtual_machine.png "Azure Virtual Machine")
+![Azure Portal Virtual Machines page with the target VM selected. Verify that the correct Arm64 Azure VM powered by Azure Cobalt 100 is selected before configuring network access.#center](images/virtual_machine.png "Azure Virtual Machine")
 
 2. In the left menu, select **Networking**, then select **Network settings**.
 
@@ -35,25 +36,19 @@ To expose the required TCP ports for Kubernetes and Longhorn, create an inbound
 - **Source IP addresses:** *(auto-populated with your current public IP)*  
 - **Source port ranges:** *  
 - **Destination:** Any  
-- **Destination port ranges:** **80,8080,6443**  
+- **Destination port ranges:** `80`,`8080`,`6443`
 - **Protocol:** TCP  
 - **Action:** Allow  
-- **Name:** allow-longhorn-kubernetes
+- **Name:** `allow-longhorn-kubernetes`
 
-This rule allows external access for:
-
-- Port `80` → HTTP workloads
-- Port `8080` → Longhorn Web UI
-- Port `6443` → Kubernetes API server
+This rule allows external access for port `80` for HTTP workloads, port `8080` for the Longhorn web UI, and port `6443` for the Kubernetes API server.
 
 {{% notice Note %}}Setting **Source** to **My IP address** restricts access to these ports to your current machine only. If your public IP address changes or you access the environment from another system, update the source IP in the NSG rule accordingly.{{% /notice %}}
 
-5. After filling in the details, select **Add** to save the rule.
+5. After configuring the rule, select **Add** to save the rule.
 
 ## What you've learned and what's next
 
-You've now configured the Azure Network Security Group to allow external traffic for Kubernetes API access, HTTP workloads, and the Longhorn Web UI.
-
-These firewall rules allow secure remote management of the Azure Cobalt 100 virtual machine and external access to the Kubernetes storage dashboard.
+You've now configured the Azure Network Security Group to allow external traffic for Kubernetes API access, HTTP workloads, and the Longhorn Web UI. These firewall rules allow secure remote management of the VM and external access to the Kubernetes storage dashboard.
 
-Next, you'll install K3s Kubernetes and Longhorn on the virtual machine, then deploy and configure persistent storage.
+Next, you'll install K3s Kubernetes and Longhorn on the VM.