How to Upgrade Failover Cluster Functional Level

When you add new nodes with a higher operating system to your Windows Failover cluster environment, you will receive warnings about "Functional Level" mismatch in your failover cluster logs.

The main reason for these warnings is that the operating systems and functional levels of the clusters connected to the nodes in your environment are different from each other.

You can follow the steps below to change the functional level compatibility;

  • To view the Failover Cluster Functional Level version
    Get-Cluster | select ClusterFunctionalLevel
  • To upgrade the Failover Cluster Functional Level version
  • To view the upgrade process of the Failover Cluster Functional Level version
    Get-Cluster | select ClusterFunctionalLevel
  • In Windows Server 2019 the Clustering team introduced a new PowerShell cmdlet to check how many nodes of the cluster are running on which level
    "Get-ClusterNodeSupportedVersion" helps you to identify the Cluster Functional Level and the Cluster Upgrade Version.

The table below shows the values and each corresponding functional level:


For more detailed information;

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How to Fix Hyper-V Failover Cluster Node Quarantine

In case you see quarantine status on your nodes in your Hyper-V Failover Clustering system,you should first examine the Cluster Events.

If the error code you will encounter while examining the cluster events is 1676, the action details you need to do are included in the error code. Don’t look for a different solution.

Open Windows Powershell –> Start-ClusterNode -ClearQuarantine

Check Cluster Node state –> Get-ClusterNode

Then go back to Failover Cluster Manager console and resume the paused node , taking fail roles back or don’t fail roles back.

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