Hotpatching is a feature in Microsoft Azure that allows users to apply operating system updates to virtual machines (VMs) without the need to restart them. This feature can help minimize downtime and reduce the need for maintenance windows.
Hotpatching works by applying updates to running processes in memory, without the need to reboot the system. This feature is available for certain updates on certain operating systems, and not all updates can be applied using hotpatching.
To use hotpatching in Azure, you need to enable it in the VM settings. You can then apply hotpatches through the Azure portal, PowerShell, or the Azure command-line interface (CLI). Once a hotpatch is applied, the VM will co
Hotpatching is a new way to install updates on new Windows Server Azure Edition virtual machines (VMs) that doesn’t require a reboot after installation and comes with 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
You can find more about this feature on Microsoft Docs.
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.Microsoft Docs
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.
- 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.
You can find more details on how hotpatch for Windows Server Azure VMs works, on Microsoft Docs.
How to get started with Hotpatch for Windows Server Azure Virtual Machines
Now you can start using hotpatching for new Azure VMs running Windows Server 2022 Datacenter: Azure Edition Core Gen2.
- 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.
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.
- Create page make sure you still have the Windows Server 2022 Datacenter: Azure Edition Core Gen2 selected.
If you now go to the virtual machines, you can manage the patch settings and review the patch status of your Azure virtual machine.
Conclusion
Azure Automanage is an excellent feature to automatically manage your Azure virtual machines, and with hotpatch for Windows Server VMs, it just became even better! It helps you to reduce reboots of your Windows Server, and with that reduce downtime.