Windows Server runs best in Microsoft Azure, especially in combination with management capabilities like Azure Automanage. Today we are announcing the general availability of Hotpatch for Windows Server 2022 Azure Edition. Hotpatching is a new way to install updates on supported Windows Server Azure Edition virtual machines (VMs) that doesn’t require a reboot after installation and drastically increase uptime oof your mission critical application workloads running on Windows Server.
Hotpatching also includes the following benefits:
Lower workload impact with less reboots
Faster deployment of updates as the packages are smaller, install faster, and have easier patch orchestration with Azure Update Manager
Better protection, as the Hotpatch update packages are scoped to Windows security updates that install faster without rebooting
How does Hotpatch for Windows Server Azure VMs work
Hotpatch works by first establishing a baseline with a Windows Update Latest Cumulative Update. Hotpatches are periodically released (for example, on the second Tuesday of the month) that build on that baseline. Hotpatches will contain updates that don't require a reboot. Periodically (starting at every three months), the baseline is refreshed with a new Latest Cumulative Update.
Hotpatch Sample Schedule
There are two types of baselines: Planned baselines and unplanned baselines.
Planned baselines are released on a regular cadence, with hotpatch releases in between. Planned baselines include all the updates in a comparable Latest Cumulative Update for that month, and require a reboot.
The sample schedule above illustrates four planned baseline releases in a calendar year (five total in the diagram), and eight hotpatch releases.
Unplanned baselines are released when an important update (such as a zero-day fix) is released, and that particular update can't be released as a Hotpatch. When unplanned baselines are released, a hotpatch release will be replaced with an unplanned baseline in that month. Unplanned baselines also include all the updates in a comparable Latest Cumulative Update for that month, and also require a reboot.
The sample schedule above illustrates two unplanned baselines that would replace the hotpatch releases for those months (the actual number of unplanned baselines in a year isn't known in advance).
You can find more details on how hotpatch for Windows Server Azure VMs works, on Microsoft Docs.
How to get started
Getting started with hotpatch and Windows Server is straight forward.
Deploy a new Azure VM with hotpatch for Windows Server enabled
To use this feature you currently need to deploy a new Azure virtual machine running the Windows Server 2022 Datacenter: Azure Edition Core Gen2 image.
Now on the create page make sure you still have the Windows Server 2022 Datacenter: Azure Edition Core Gen2 selected.
Create Windows Server 2022 Datacenter Azure Edition Core Gen2 Hotpatch Virtual machine VM
To use this feature, you currently need to deploy a new Azure virtual machine running the Windows Server 2022 Datacenter: Azure Edition Core Gen2 image.
Enable Hotpach Azure VM
If you now go to the virtual machines, you can manage the patch settings and review the patch status of your Azure virtual machine.
Manage Guest patches Hotpach Azure VM
Here you can find an overview of missing updates of the virtual machine.
Azure VM Windows Server Hotpatch Update Overview
If you want to learn more about Windows Server hotpatching, check out Microsoft Docs.