Set Azure Server Reboot Window

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Set Azure Server Reboot Window

Cathy in Maine 36

Azure Server 2022 File server rebooted while users were accessing files. It was an Azure reboot and they did get a message, but had no time to save. How can I set the server to not reboot during a certain window?

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Answer 1

Hemalatha 14,525 Microsoft External Staff Moderator

Hi Cathy in Maine,

Thanks for reaching out Q/A. To control Azure-initiated reboots and avoid downtime during working hours, please review the following recommendations:

Use Azure Update Manager or Maintenance Configurations:

Azure allows you to define maintenance windows, so updates and reboots happen outside of critical usage times.

In the Azure Portal, go to Update Manager >> Machines >> Schedule updates.
Create a maintenance configuration with (A time window outside business hours and Reboot settings: Never reboot or Reboot if required)

Reference: https://learn.microsoft.com/en-us/azure/update-manager/configure-wu-agent

2.You’ll need to configure your VM's Windows Update settings. You can set "ActiveHoursStart" and "ActiveHoursEnd" in the Windows Registry to specify the time window in which reboots should not occur.

Adjust the following registry entries:

HKLM\Software\Policies\Microsoft\Windows\WindowsUpdate

ActiveHoursStart and ActiveHoursEnd: Define the start and end of your active hours.

SetActiveHours: Set this to 1 to enable active hours.

HKLM\Software\Policies\Microsoft\Windows\WindowsUpdate\AU

NoAutoRebootWithLoggedOnUsers: Set to 1 to prevent reboots when users are logged in.

Azure may perform planned maintenance which could require a reboot. You can check the Scheduled Maintenance Notifications and be informed in advance of any scheduled maintenance that affects your VM.

In some cases, Azure performs host-level (platform) maintenance that can restart your VM. While it is not possible to completely prevent these updates, you can control their timing if your VM type supports Maintenance Control.

To configure Maintenance Control:

Navigate to Azure Portal >> Maintenance configurations >> Create configuration.
Select the scope (Host).
Assign supported resources, such as Dedicated Hosts, Isolated VMs, or supported VM scale sets.
Define your preferred maintenance window for Azure to apply updates.

Reference: https://learn.microsoft.com/en-us/azure/virtual-machines/maintenance-configurations

If your VM does not appear in the Select resources list, it is likely running on shared infrastructure, which does not support Maintenance Control. In such cases, you will still receive advance Scheduled Maintenance Notifications in the Azure Portal whenever host maintenance is planned.

Please let me know if you have any questions or need further assistance

Cathy in Maine 36 Reputation points

2025-10-27T13:17:03.6766667+00:00

I went through everything, but now I'm getting this:

"Some virtual machines aren't available due to unsupported patch orchestration options."
Hemalatha 14,525 Reputation points Microsoft External Staff Moderator

2025-10-27T14:05:41.66+00:00
Thank you for your update, and for sharing the details of the message you’re seeing:
"Some virtual machines aren't available due to unsupported patch orchestration options."

This message appears because your VM’s patch orchestration mode is currently set to Windows automatic updates, which does not support full management through Azure Update Manager. As a result, centralized scheduling and patch deployment via Azure Update Manager are unavailable for this configuration.

To allow Azure Update Manager to manage update schedules, patch installation, and reboot coordination, please update the patch orchestration mode to a supported option, such as:

Steps to Update the Patch Orchestration Mode

In the Azure portal, navigate to your Virtual Machine.

Under the Settings section in the left pane, select Updates.

Click Update settings.

In the Patch orchestration dropdown, choose one of the supported options (for example, Customer Managed Schedules or Azure Managed – Safe Deployment).

Save your changes.

You can refer to the screenshot for guidance on where these options appear.

After updating this configuration, your VM will become available for automated patching and reboot scheduling via Azure Update Manager. This will resolve the orchestration issue and allow you to control maintenance windows as desired.

Please find the below documentations for reference:

https://learn.microsoft.com/en-us/azure/update-manager/updates-maintenance-schedules

https://learn.microsoft.com/en-us/azure/update-manager/dynamic-scope-overview?tabs=avms#enable-schedule-patching-on-azure-vms

https://learn.microsoft.com/en-us/azure/update-manager/troubleshoot?tabs=azure-machines
Cathy in Maine 36 Reputation points

2025-10-27T16:47:29.59+00:00

Thank you very much for your help! I have set up Azure Managed – Safe Deployment and Maintenance Windows.
Hemalatha 14,525 Reputation points Microsoft External Staff Moderator

2025-10-27T16:50:45.45+00:00

Thanks for update Cathy in Maine

If it is helpful! Could you please accept the answer and upvote it so it will be helpful to community members as well.

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Set Azure Server Reboot Window

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