Merge pull request #54048 from staleycyn/patch-1

Content-drift vm availability

Author: v-ccolin

learn-pr/wwl-azure/configure-virtual-machine-availability/includes/3-setup-availability-sets.md

@@ -18,11 +18,10 @@ Let's review some characteristics of availability sets.
 
 - You can build availability sets by using the Azure portal, Azure Resource Manager (ARM) templates, scripting, or API tools.
 
-- Microsoft provides robust Service Level Agreements (SLAs) for Azure virtual machines and availability sets. For details, see [SLA for Azure Virtual Machines](https://azure.microsoft.com/support/legal/sla/virtual-machines/v1_9/).
+
 
 > [!NOTE]
-> Adding your virtual machines to an availability set won't protect your applications from operating system or application-specific failures.
-> You'll need to explore other disaster recovery and backup techniques to provide application-level protection.
+> Adding your virtual machines to an availability set doesn't protect your applications from operating system or application-specific failures. You need to explore other disaster recovery and backup techniques to provide application-level protection.
 
 ### Things to consider when using availability sets
 
@@ -34,4 +33,4 @@ Availability sets are an essential capability when you want to build reliable cl
 
 - **Consider load balancing**. For high availability and network performance, create a load-balanced availability set by using Azure Load Balancer. Load Balancer distributes incoming traffic across working instances of services that are defined in your load-balanced availability set.
 
-- **Consider managed disks**. You can use Azure managed disks with your Azure virtual machines in availability sets for block-level storage.
+- **Consider managed disks**. You can use Azure managed disks with your Azure virtual machines in availability sets for block-level storage.

learn-pr/wwl-azure/configure-virtual-machine-availability/includes/4-review-update-fault-domains.md

@@ -8,9 +8,10 @@ An update domain is a group of nodes that are upgraded together during the proce
 
 - During planned maintenance, only one update domain is rebooted at a time.
 
-- By default, there are five (non-user-configurable) update domains.
+- You can specify between 1 and 20 update domains when creating an availability set.  If you don't specify a value, Azure defaults to five update domains.
+  
+- The update domain count is immutable after creation; to change it, you must delete and recreate the availability set.
 
-- You can configure up to 20 update domains.
 
 ### Things to know about fault domains
 
@@ -22,4 +23,4 @@ A fault domain is a group of nodes that represent a physical unit of failure. Th
 
 Let's look at a scenario with two fault domains that have two virtual machines each. The virtual machines in each fault domain are contained in different availability sets. The web availability set contains two virtual machines with one machine from each fault domain. The SQL availability set contains two different virtual machines with one from each fault domain.
 
-:::image type="content" source="../media/update-fault-domains-c1ceee00.png" alt-text="Illustration that shows two fault domains with two virtual machines each. The virtual machines in each fault domain are contained in different availability sets." border="false":::
+:::image type="content" source="../media/update-fault-domains-c1ceee00.png" alt-text="Illustration that shows two fault domains with two virtual machines each. The virtual machines in each fault domain are contained in different availability sets." border="false":::

learn-pr/wwl-azure/configure-virtual-machine-availability/includes/5-review-availability-zones.md

@@ -23,8 +23,11 @@ Azure services that support availability zones are divided into two categories.
 
 | Category | Description | Examples |
 | --- | --- | --- |
-| **Zonal services** | Azure _zonal_ services pin each resource to a specific zone. | - Azure Virtual Machines <br> - Azure managed disks <br> - Standard IP addresses |
+| **Zonal services** | Azure _zonal_ services pin each resource to a specific zone. | - Azure virtual machines <br> - Azure managed disks  |
 | **Zone-redundant services** | For Azure services that are zone-redundant, the platform replicates automatically across all zones. | - Azure Storage that's zone-redundant <br> - Azure SQL Database |
 
+> [!Note]
+> > Note: Standard IP addresses can be configured as zone-redundant (recommended for high availability), zonal (pinned to a specific zone), or non-zonal (regional) depending on your deployment choice.
+
 > [!Tip]
 > To achieve comprehensive business continuity on Azure, build your application architecture with a combination of availability zones and Azure [regional pairs](/azure/virtual-machines/regions#region-pairs).

learn-pr/wwl-azure/configure-virtual-machine-availability/includes/7-implement-scale-sets.md

@@ -11,12 +11,12 @@ With Virtual Machine Scale Sets, you don't need to pre-provision your virtual ma
 
 Review the following characteristics of Azure Virtual Machine Scale Sets.
 
-- All virtual machine instances are created from the same base operating system image and configuration. This approach lets you easily manage hundreds of virtual machines without extra configuration tasks or network management.
 
 - Virtual Machine Scale Sets support the use of Azure Load Balancer for basic layer-4 traffic distribution, and Azure Application Gateway for more advanced layer-7 traffic distribution and TLS/SSL termination.
 
 - You can use Virtual Machine Scale Sets to run multiple instances of your application. If one of the virtual machine instances has a problem, customers continue to access your application through another virtual machine instance with minimal interruption.
 
+- There are two types of orchestration modes available for Azure virtual machine scale sets: Uniform and Flexible. In **Uniform orchestration mode**, all virtual machine instances are created from the same base operating system image and configuration. In **Flexible orchestration mode**, VMs can use different images, sizes, or configurations within the same scale set. The orchestration mode must be chosen when the scale set is created.
+
 - Customer demand for your application might change throughout the day or week. To meet customer demand, Virtual Machine Scale Sets implements autoscaling to automatically increase and decrease the number of virtual machines.
 
-- Virtual Machine Scale Sets support up to 1,000 virtual machine instances. If you create and upload your own custom virtual machine images, the limit is 600 virtual machine instances.

learn-pr/wwl-azure/configure-virtual-machine-availability/includes/8-create-scale-sets.md

@@ -5,7 +5,7 @@ In the Azure portal, there are several settings to configure to create an Azure
 :::image type="content" source="../media/implement-scale-sets-61516afb.png" alt-text="Screenshot that shows how to create Virtual Machine Scale Sets in the Azure portal.":::
 
 
-- [**Orchestration mode**](/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-orchestration-modes): Choose how the scale set manages the virtual machines. In flexible orchestration mode, you manually create and add a virtual machine of any configuration to the scale set. In uniform orchestration mode, you define a virtual machine model and Azure generates identical instances based on that model.
+- [**Orchestration mode**](/azure/virtual-machine-scale-sets/virtual-machine-scale-sets-orchestration-modes): Choose how the scale set manages the virtual machines. Flexible orchestration is the default and recommended mode for new deployments. For most new workloads, accept the Flexible default unless you have a specific requirement for identical instances.
 
 - **Image**: Choose the base operating system or application for the VM.
 
@@ -15,4 +15,4 @@ In the Azure portal, there are several settings to configure to create an Azure
 
 Under the **Advanced** tab, you can also select the following: 
 
-- **Spreading algorithm**: The spreading algorithm determines how VMs in the scale set are balanced across fault domains. With max spreading, VMs are spread across as many fault domains as possible in each zone. With fixed spreading, VMs are always spread across exactly five fault domains. In the case where fewer than five fault domains are available, a scale set using "Max spreading" completes, while a scale set using "Fixed spreading" fails. For this reason, Microsoft recommends using **Max spreading** for your implementation. 
+- **Spreading algorithm**: The spreading algorithm determines how VMs in the scale set are balanced across fault domains. With max spreading, VMs are spread across as many fault domains as possible in each zone. With fixed spreading, VMs are always spread across exactly five fault domains. In the case where fewer than five fault domains are available, a scale set using "Max spreading" completes, while a scale set using "Fixed spreading" fails. For this reason, Microsoft recommends using **Max spreading** for your implementation. 

learn-pr/wwl-azure/configure-virtual-machine-availability/index.yml

@@ -3,7 +3,7 @@ uid: learn.wwl.configure-virtual-machine-availability
 metadata:
   title: Configure Virtual Machine Availability
   description: "Learn how to configure virtual machine availability including vertical and horizontal scaling."
-  ms.date: 02/12/2026
+  ms.date: 03/23/2026
   author: wwlpublish
   ms.author: cynthist
   ms.topic: module