Merge pull request #216398 from pruphil/pphillips-maintenance-config-changes

added important limitation to host scope

Author: denrea

articles/virtual-machines/maintenance-configurations.md

@@ -15,7 +15,7 @@ ms.author: cynthn
 
 **Applies to:** :heavy_check_mark: Linux VMs :heavy_check_mark: Windows VMs :heavy_check_mark: Flexible scale sets :heavy_check_mark: Uniform scale sets
 
-Maintenance Configurations give you the ability to control and manage updates for many Azure virtual machine resources since Azure frequently updates its infrastructure to improve reliability, performance, security or launch new features. Most updates are transparent to users, but some sensitive workloads, like gaming, media streaming, and financial transactions, can't tolerate even few seconds of a VM freezing or disconnecting for maintenance. Maintenance configurations is integrated with Azure Resource Graph (ARG) for low latency and high scale customer experience. 
+Maintenance Configurations gives you the ability to control and manage updates for many Azure virtual machine resources since Azure frequently updates its infrastructure to improve reliability, performance, security or launch new features. Most updates are transparent to users, but some sensitive workloads, like gaming, media streaming, and financial transactions, can't tolerate even few seconds of a VM freezing or disconnecting for maintenance. Maintenance Configurations is integrated with Azure Resource Graph (ARG) for low latency and high scale customer experience.
 
 >[!IMPORTANT]
 > Users are required to have a role of at least contributor in order to use maintenance configurations.
@@ -24,38 +24,40 @@ Maintenance Configurations give you the ability to control and manage updates fo
 
 Maintenance Configurations currently supports three (3) scopes: Host, OS image, and Guest. While each scope allows scheduling and managing updates, the major difference lies in the resource they each support. This section outlines the details on the various scopes and their supported types:
 
-
 | Scope    | Support Resources          |
 |----------|----------------------------|
 | Host     | Isolated Virtual Machines, Isolated Virtual Machine Scale Sets, Dedicated Hosts  |
 | OS Image | Virtual Machine Scale Sets |
 | Guest    | Virtual Machines, Azure Arc Servers |
 
-
 ### Host
+
 With this scope, you can manage platform updates that do not require a reboot on your *isolated VMs*, *isolated Virtual Machine Scale Set instances* and *dedicated hosts*. Some features and limitations unique to the host scope are:
 
 - Schedules can be set anytime within 35 days. After 35 days, updates are automatically applied.
 - A minimum of a 2 hour maintenance window is required for this scope.
+- Rack level maintenance is not currently supported.
 
 [Learn more about Azure Dedicated Hosts](dedicated-hosts.md)
 
 ### OS image
-Using this scope with maintenance configurations lets you decide when to apply upgrades to OS disks in your *virtual machine scale sets* through an easier and more predictable experience. An upgrade works by replacing the OS disk of a VM with a new disk created using the latest image version. Any configured extensions and custom data scripts are run on the OS disk, while data disks are retained. Some features and limitations unique to this scope are: 
 
-- Scale sets need to have [automatic OS upgrades](../virtual-machine-scale-sets/virtual-machine-scale-sets-automatic-upgrade.md) enabled in order to use maintenance configurations.
-- Schedule recurrence is defaulted to daily 
-- A minimum of 5 hours is required for the maintenance window
+Using this scope with maintenance configurations lets you decide when to apply upgrades to OS disks in your *Virtual Machine Scale Sets* through an easier and more predictable experience. An upgrade works by replacing the OS disk of a VM with a new disk created using the latest image version. Any configured extensions and custom data scripts are run on the OS disk, while data disks are retained. Some features and limitations unique to this scope are:
+
+- Scale sets need to have [automatic OS upgrades](/articles/virtual-machine-scale-sets/virtual-machine-scale-sets-automatic-upgrade.md) enabled in order to use maintenance configurations.
+- You can schedule recurrence up to a week (7 days).
+- A minimum of 5 hours is required for the maintenance window.
 
 ### Guest
+
 This scope is integrated with [update management center](../update-center/overview.md) which allows you to save recurring deployment schedules to install updates for your Windows Server and Linux machines in Azure, in on-premises environments, and in other cloud environments connected using Azure Arc-enabled servers. Some features and limitations unique to this scope include:
 
 - [Patch orchestration](automatic-vm-guest-patching.md#patch-orchestration-modes) for virtual machines need to be set to AutomaticByPlatform
 - A minimum of 1 hour and 10 minutes is required for the maintenance window.
-- There is no limit to the recurrence of your schedule 
+- There is no limit to the recurrence of your schedule.
 
 To learn more about this topic, checkout [update management center and scheduled patching](../update-center/scheduled-patching.md)
- 
+
 ## Management options
 
 You can create and manage maintenance configurations using any of the following options:
@@ -68,4 +70,4 @@ For an Azure Functions sample, see [Scheduling Maintenance Updates with Maintena
 
 ## Next steps
 
-To learn more, see [Maintenance and updates](maintenance-and-updates.md).
+To learn more, see [Maintenance and updates](maintenance-and-updates.md).