Tag: Failover Cluster

Cluster Functional Level and Cluster Upgrade Version

Learn about Windows Server Cluster Functional Levels

A couple of weeks ago, I released a blog post about Hyper-V VM Configuration versions to give an overview about the version history of Hyper-V virtual machines. After that I had the chance to work with John Marlin (Microsoft Senior Program Manager High Availability and Storage) on a similar list of Windows Server Cluster Functional Levels.

Why Cluster Functional Levels are important

With Windows Server 2016, Microsoft introduced a new feature called Cluster OS Rolling Upgrade or Cluster Rolling Upgrade. This feature allows you to upgrade the operating system of the cluster nodes to a new version, without stopping the cluster. With mixed-OS mode, you can have for example 2012 R2 and 2016 nodes in the same cluster. Keep in mind that this should only be temporary, while you are upgrading the cluster. You can basically upgrade node by node, and after all nodes are upgraded, you then upgrade the Cluster functional Level to the latest version.

List of Windows Server Cluster Functional Levels

Since the feature Cluster OS Rolling Upgrade was first introduced with Windows Server 2016, you never really knew about Cluster Functional Levels before. However, it already existed since Windows Server NT4.

Windows Server VersionCluster Functional Level
Windows Server 201911
Windows Server RS410.3
Windows Server RS310.2
Windows Server 20169
Windows Server 2012 R28
Windows Server 20127
Windows Server 2008 R26
Windows Server 20085
Windows Server 2003 R24
Windows Server 20033
Windows Server 20002
Windows Server NT41

Tips and PowerShell

If you want to know more about Cluster OS Rolling Upgrade, you can check out the Microsoft Docs. Together with John, I created a quick list of some tips for you, and some of the important PowerShell cmdlets.

To check which Cluster Functional Levels your cluster is running on, you can use the following PowerShell cmdlet:

If you have upgraded all nodes in the cluster, you can use the Update-ClusterFunctionalLevel to update the Cluster Functional Level. Also make sure that you upgrade the workloads running in that cluster, for example upgrade the Hyper-V Configuration Version or in a Storage Spaces Direct Cluster, the Storage Pool version (Update-StoragePool).

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.

Cluster Functional Level Get-ClusterNodeSupportedVersion

This means that the functional level is 11 (Windows 2019).  The Upgrade version column is what you can upgrade to/with, meaning 11.1 or Windows 2019 only.

Cluster Functional Level and Cluster Upgrade Version

This means your Cluster Functional Level is 10.  Meaning you can add basically anything 10.x (2016, RS3, RS4) and 11 (2019) to it.

If you are running System Center Virtual Machine Manager, the Cluster OS rolling upgrade, can be fully automated as well. Check out the Microsoft Docs for Perform a rolling upgrade of a Hyper-V host cluster to Windows Server 2016 in VMM.

To find out more about information Cluster operating system rolling upgrade, like how-to, requirements and limitations, check out the Microsoft Windows Server Docs page.

Windows Server

Recommend Hotfixes and Updates for Hyper-V and Failover Clusters

I the last couple of releases I always posted the pages where you could get the list of Recommended Hotfixes and Updates for Windows Server 2012 Failover Clusters and List of Hyper-V and Failover Cluster Hotfixes for Windows Server 2012. I want to upgrade the post with the links for Windows Server 2008 R2, Windows Server 2012 and Windows Server 2012 R2. So you can find all updates from a single site.

Windows Server 2012 R2

Windows Server 2012

Windows Server 2008 R2

Feel free to share this page and I always recommend to get the latest hotfixes when you are deploying a new Hyper-V or Scale-Out File Server environment. And definitely check also Aidan Finns blog from time to time where he does some deeper look at the Knowledge Base articles for Hyper-V.


Recommended Hotfixes and Updates for Windows Server 2012 Failover Clusters

Windows Server 2012 Logo

Back in March I posted links to two TechNet Wiki Pages where all the available Failover Cluster and Hyper-V hotfixes were listed (List of Hyper-V and Failover Cluster Hotfixes for Windows Server 2012). Now the Microsoft Cluster team created an offical knowledge base article (KB2784261) for recommended hotfixes and updates for Windows Server 2012-based Failover Clusters. Make sure you check this list of hotfixes before you go in production with your Windows Server 2012 cluster.

There are some really important fixes especially if you are running a Windows Server 2012 Hyper-V cluster and you are using Cluster Shared Volumes.

You can find more information on KB2784261 – Recommended hotfixes and updates for Windows Server 2012-based Failover Clusters.


Migrate Hyper-V Cluster to Windows Server 2012 Hyper-V via Cluster Migration Wizard

Windows Server 2012 Logo

If you have already an existing Windows Server 2008 R2 Hyper-V cluster and you want to upgrade to Windows Server 2012 you have two options. The first one is by moving all virtual machines via System Center Virtual Machine Manager from the old Cluster into a new cluster. The second way to do it, is to use the Cluster Migration Wizard which is part of Windows Server 2012.

In my case I have two clusters one “old” Windows Server 2008 R2 Hyper-V cluster and my new Windows Server 2012 Hyper-V cluster. Both Clusters are fully configured and both have access to the same disks/LUNs. The disk and all the VMs are running on the old cluster.

On the new cluster you can start the Cluster Migration Wizard.

Failover Cluster Manager Migrate Roles

This will bring up the Cluster Migration Wizard. The wizard will ask you about the old cluster.

Cluster Migration Wizard Old Cluster

The Cluster Migration Wizard will scan the old cluster for CSVs and Cluster roles. You have to select the Cluster Shared Volume you want to migrate to the new cluster. Note: you can only migrate CSVs including all virtual machines running on this CSV and not just single virtual machines. If you want to migrate single virtual machines you could do a Hyper-V Export/Import or using System Center Virtual Machine Manager.

Cluster Migration Wizard Old Cluster Roles

Since the Cluster Migration Wizard detects the roles as Hyper-V virtual machines he also asks for the new Hyper-V Virtual Switch.

Cluster Migration Wizard Hyper-V Virtual Switch

You get a quick summary with all the information what the Migration Wizard will do, and you can migrate all roles. This means the Migration Wizard will create all cluster roles on the new cluster but will not take the existing VMs offline the VMs at this point are still running on the old cluster. You also get a Failover Cluster Migration Report at the end.

Failover Cluster Migration Report

This report also shows you what’s next:

All the clustered services and applications selected for migration were migrated successfully. You may now take the clustered services and applications offline in your old cluster. Also take offline Cluster Shared Volumes used by any migrated roles, as well as storage pools for virtual disks used by any migrated roles. Then these disks, Cluster Shared Volumes, and clustered services and applications can be brought online in your new cluster.

In the new cluster you can now see the roles which are all turned of because there are still running on the old cluster. And you can also see the CSV which is offline on the new cluster and online on the old cluster.

Failover Cluster Migration new roles

As already mentioned we had no downtime until now. Now you can go and shutdown all the virtual machines running on your old cluster and take the migrated CSV offline.

Failover Cluster Migration shutdown VMS

Take the CSV offline

Failover Cluster Migration take CSV offline

On the new cluster bring the CSV online

Failover Cluster Migration bring CSV online

Bring the virtual machines on the new cluster back online.

Failover Cluster Migration bring VMs back online

And this is more how you can migrate a cluster. Remember there are still some tasks left.

There is also a great video from Symon Perriman and Rob Hindman, a Program Manager on the Windows Server Clustering & High-Availability team, in which they explain how you can upgrade to Windows Server 2012 Hyper-V.


List of Hyper-V and Failover Cluster Hotfixes for Windows Server 2012

Windows Server 2012 Logo

As for Windows Server 2008 R2 Microsoft created a TechNet Wiki page with the list for Hyper-V and Failover Cluster hotfixes for Windows Server 2012. This will help you find hotfixes for problems you may experience.

List of Hyper-V Hotfixes for Windows Server 2012 (TechNet Wiki):


List of Failover Cluster Hotfixes for Windows Server 2012 (TechNet Wiki):


Source: Hans Vredevoort (MVP Virtual Machine) Hyper-V.nu

How to make an existing Hyper-V Virtual Machine Highly Available

Windows Server 2012 Logo

If you have a running Hyper-V Virtual Machine with is not part of a cluster you can make this virtual machine highly available via the Failover Cluster Manager. First of all the Virtual Machine has to be stored on a shared storage. In Windows Server 2008 R2 this means the Virtual Machine and the attached Virtual Disks had to be stored on a Cluster Shared Volume (C:\ClusterStorage\…), with Windows Server 2012 the VM could also be stored on a SMB 3.0 file share.

Windows Server 2008 R2 Make Virtual Machine Highly Available

And there is also a big difference in Windows Server 2008 R2 Hyper-V and in Windows Server 2012 Hyper-V. In Windows Server 2008 R2 the Virtual Machine had to be offline during you add the VM to the Cluster, and in Windows Server 2012 you can do this online.

First open the Failover Cluster Manager and right click on your Cluster Name in the menu select “Configure Role”

Windows Server 2012 Failover Cluster Manager Configure Role

This started the High Availability Wizard. First select the role you want to make high available, in the Hyper-V case this is “Virtual Machine”.

Windows Server 2012 Failover Cluster Manager High Availability Wizard

Now select the Virtual Machine you want to add to the cluster. Note: In Windows Server 2012 the Virtual Machine can be online, in Windows Server 2008 R2 the Virtual Machine had to be offline.

Select Virtual MachineAfter clicking next on the wizard, you the VMs will be added to the Failover Cluster.

Btw. thanks to Philipp Witschi (itnetx), who I now owe a dinner.


Failover Cluster Manager Error caused by KB2750149

Hans Vredevoort (MVP Virtual Machine) yesterday reported a issue with one of the January updates for Windows Server 2012. After he deployed the latest Windows Updates from January to the Windows Server 2012 Hyper-V Cluster it was not possible to view the roles of this Cluster and got the following error:

Windows Server 2012 Failover Cluster Error

The issue only affect the MMC with the Failover Cluster Manager. All roles on the Cluster still run fine and without any issues.

After he reported this problem, he got a quick note from the Microsoft cluster team that KB2750149 was the cause of this problem and that the current advice is to uninstall this update until further notice.

Thanks to Hans for reporting this issue.