Book Tipp: Introduction to Windows Server Failover Clustering

Hi everybody,

5nine Software Vice President Symon Perriman published a book with some cool best practices for configuration Windows Server Failover Clusters. ūüôā

Greate stuff and great to read.

You can download it here.

Where to find logs from cluster role movement?

Hi everybody,

as you know sometimes it is neccessary to get some more information about where and when roles within a cluster were successfully moved from one node to another.

One example could be Hyper-V Livemigrations or role movements from mixed role cluster servers.

When you have errors or warnings during rolemigrations, you can see the events directly within the failover cluster manager.

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But what is if I want to see successfull role moves? Where do I find them?

Those messages are a bit hidden within the logfile structures of a Windows Server.

  1. Navigate to Applications and Services Logs\Microsoft\Windows\Failover Clustering\Operational
  2. There you can find several events dependig if you are on the role sender or receiver2016-02-19_11-07-222016-02-19_11-07-522016-02-19_11-08-14

You install Hyper-V & VMM from the green? Please do it in the right order.

Hi everybody,

today another story I see most of the days when I do Healthcheck on customer site.

One of the first things I found was a new VMM installation on top of a new Microsoft Hyper-V Cluster. The issue was, that the cluster was installed first and every thing was running on Hyper-V converged network and standard Hyper-V Switches. There was no VMM network configured or the host made compliant within VMM.

Why is that so bad? It’s bad because VMM uses it’s own kind of switches (logical switches) and needs some additional configurations to manage the hosts in the best possible way.

When I ask guy’s why they do it in that way, I normally get the answer “how should I configure the host when no VMM is in place before he install the cluster?”.

So now my answer and how you can do it in the right way.

  1. Install a Hyper-V Host as Standalone host
  2. Configure and install the VMs for VMM and SQL Server (if needed) on the standalone host
  3. Performe the ful VMM configuration
  4. Install the other Hyper-V Hosts and roll out the VMM configuration to that hosts
  5. Cluster the Hyper-V Hosts
  6. Migrate your SQL DB and VMM with shared nothing livemigration to the new Hyper-V Cluster
  7. Reconfigure the standalone Hyper-V Host with VMM and add it to the cluster
  8. Run the cluster validation again

That’s all and it will cost you the same amount of time.

Small scripts to configure Livemigration on Hyper-V Hosts & Cluster

Hi everybody,

based on blogposts by¬†John Savill and Ben Armstrong I developed two small scripts to configure Livemigration on Hyper-V Hosts and Cluster to save some time for configuration. I will no provide my whole script but I think the two snipes will help you too ūüôā

First one you run on all Hyper-V Hosts.

The next one you run on the cluster its self. You only need to run one, depending on what suits you best.

 

 

Cluster Manager, Server Manager & Hyper-V Console not starting

This week I had a very strange issue with a Hyper-V Cluster managed by Virtual Machine Manager.

Completely randomly different cluster nodes failed and I weren’t able to start failover cluster manager on one of the cluster nodes. ¬†On the infected node it self, I wasn’t able to open the hyper-v manager or server manager.

After a lot of research I found a solution from the windows server core team which pointed me to the solution.

Unable to launch Cluster Failover Manager on any node of a 2012/2012R2 Cluster

When Failover Cluster Manager is opened to manage a Cluster, it will contact all the nodes and retrieve Cluster configuration information using WMI calls. If any one of the nodes in the Cluster does not have the cluster namespace “root\mscluster” in WMI, Failover Cluster Manager will fail and give one of the below errors:

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Or,

Unfortunately, it does not give any indication of which node is missing the WMI namespace.  One of the ways you can check to see which one has it missing is to run the below command on each node of the Cluster.

It can be a bit tedious and time consuming if you have quite a few nodes, say like 64 of them.  The below script can be run on one of the nodes that will connect to all the other nodes and check to see if the namespace is present.  If it is, it will succeed.  If the namespace does not exist, it will fail.

—————–

 
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In the below example, you can see that one of the nodes failed.

To correct the problem, you would need to run the below from an administrative command prompt on the “failed” node(s).

cd c:\windows\system32\wbem
mofcomp.exe cluswmi.mof

Once the Cluster WMI has been added back, you can successfully open Failover Cluster Management.  There is no restart of the machine or the Cluster Service needed.

Quote: Microsoft Ask the Core Team Blog

In my case I wasn’t able to fix it so easy because the server vendor implemented the WMI Provider directly in his BMC via Agent (for the interested ones Fujitsu). during the process of recompiling the WMI for the Cluster the whole Server Network interfaces and BMC fail.

so my fix:

  1. shutdown the server
  2. make it powerless
  3. start it
  4. check cluster (everything fine)
  5. uninstall the (fucking) agent

Since than it worked.