Can I use Windows Server hotpatching on on-premises Hyper-V VMs?
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MellowCedar42
I'm migrating from VMware to Hyper-V and, once the move is complete, I'd like to implement hotpatching for my servers. Is hotpatching available for on-premises Hyper-V virtual machines, or does it require running the servers as Azure VMs?
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For Windows Server 2025, hotpatching can be enabled on eligible on-premises systems through Azure Arc, but it requires a per-core subscription and the servers must be Arc-enabled. If you also run Linux, look into kernel livepatch options such as Kpatch or Canonical Livepatch. These approaches rely on vendor-provided fixes that reduce the need for monthly reboots.
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You don’t necessarily need Azure VMs. Supported Windows Server versions can use hotpatching through Azure Arc-enabled servers, including eligible on-premises Hyper-V VMs. Check the exact Windows Server version, licensing model, Azure Arc requirements, and subscription costs before building your design around it.
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MellowCedar42: That matches what I found too—the feature isn’t free, so I’ll need to account for the Microsoft subscription. While planning the Hyper-V cluster, I’m also being careful with CSV BitLocker: I’ll keep a domain controller outside the cluster and avoid placing all domain controllers on the same CSV. I’m also planning to use a witness outside the cluster where possible.