In a Hyper-V failover cluster environment, the best practice for the “Automatic Stop Action” setting is to set it to “Turn Off the virtual machine.” This recommendation may seem counterintuitive at first, but it is crucial for ensuring high availability and proper failover functionality within the cluster.
Why “Turn Off” is Recommended
In a failover cluster, the cluster service manages the state and movement of virtual machines (VMs). Setting the automatic stop action to “Turn Off” prevents the Hyper-V host from initiating any shutdown procedures on the VMs when the host itself is shut down. This allows the cluster to take over and handle the VMs appropriately, such as live migrating them to another node.
If you set the automatic stop action to “Save the virtual machine state” or “Shut down the guest operating system,” it can conflict with the cluster’s efforts to manage the VMs during a failover or host shutdown.
Understanding Other Options
- Save the Virtual Machine State: This option saves the current state of the VM to disk. While this might be suitable for standalone Hyper-V hosts, in a clustered environment, it can hinder the cluster’s ability to failover the VM seamlessly.
- Shut Down the Guest Operating System: This initiates a graceful shutdown of the VM’s operating system. This process takes time and might not complete before the host shuts down.
Conclusion
Setting the “Automatic Stop Action” to “Turn Off” in a Hyper-V failover cluster ensures that the cluster service retains full control over VM management during host shutdowns. This configuration aligns with best practices for high availability and prevents potential conflicts that could disrupt VM operations.