Quorum Drive in Failover Cluster(Windows Server 2008R2)?

Let me share one of the interesting conversations I had couple of days ago with one of my colleagues.  This was regarding Quorum Drive in Failover Cluster(This was Windows Server 2008R2).

Let me tell you the story in short. ” She had a Question regarding Quorum(Q Drive typically) disappearing from Failover Cluster Manager. She also verified all the 3 Nodes(Remember this was a 3 Node Cluster) in the cluster and was not able to locate the Q Drive.

So, is this Normal in Failover Cluster?? The Answer is Absolutely Yes, this is perfectly normal for any Failover Cluster(Starting Win Server 2008) with Odd Number of Nodes. Quorum Drive is not mandatory anymore starting Win Server 2008. This might be really confusing for folks who are coming from Windows Server 2003! Yes, you heard it right..There is no need of having a dedicated Drive to act as Quorum. In this case our Cluster Quorum was configured as “Node Majority“. In Other Words, all the nodes will be participating in forming a Quorum and will be voting. If one Node dies, we still have 2 nodes Up and Running(so, we still have Majority of votes) and hence our cluster will be running without any issues. If 2 Nodes dies, majority of Nodes are down, at this point our cluster goes down. The basic idea is to avoid single point of failure!

Modes of Quorum starting Windows Server 2008:

Node Majority: Each node that is available can vote. The cluster functions only with majority of the votes. – For Odd Number of Nodes.

Node and Disk Majority: Each node + a Dedicated Drive(Typically Q) will be voting. – For Even Number of Nodes.

Node and File Share Majority: Each node + File Share Witness will be voting. ( Personally, I wouldn’t prefer this for any number of nodes)

No Majority(aka Disk only): This is what we used to have till Windows Server 2003, where a dedicated Disk will be acting as a Quorum.

Note: Leave the Quorum Config as is, chosen by windows by default when configuring the cluster.  Windows is smart enough to choose appropriate Quorum configuration for your cluster. Change only if you are sure about what you are doing. Also, please note that Quorum configuration can be changed any time even after creating a cluster.

In My lab, I’ve a 2 Node Single Instance Cluster. So I’ve Node and Disk Majority as my Quorum. Please see below screenshots.

See Quorum Configuration as Node and Disk Majority. ( Just Ignore the warning above :D, my Node2 is turned off as of now, hence that warning!)

How to change the Quorum Configuration?

Right click on your Windows Cluster and choose More Actions as shown below.

Now, you can click Next and choose your Quorum Configuration type and proceed further.

Just want to remind again, Don’t change anything unless you understand completely what you are doing!!…

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Cluster Group in Failover Cluster Manager- Windows Server 2008/2008R2??…

Where did Cluster Group go starting Windows Server 2008? Did microsoft really removed the concept of Cluster group starting Win Server 2008??…

If you worked a long time on Windows Server 2003 Clusters, you will definitely know what a cluster group is. In 2003, we used to have a concept called “Groups”. One of the groups which it displays is “Cluster Group”, when you open your Cluster Administrator(Cluadmin). If you are new to clustering,  just to keep it very simple Cluster group is the Core of your Cluster. If your Cluster group is down, basically your entire cluster(all the applications, resources etc) are down.

Things got drastically changed starting Windows Server 2008. Basically we should no longer call it as “MicroSoft Cluster Services(MSCS)“. They renamed it to simply “Failover Cluster Services”. IMHO, this makes it very clear that we are not referring to NLB(Network Load Balancing) – which is one of the flavors of Clustering Services offered by Windows Servers.

Note: Failover Cluster and Network Load Balancing Cluster are completely two different entities, no way related to each other.

Anyways, let’s see where can we see the cluster Group in Failover Cluster Manager in Win Server 2008. Assuming you’ve already Installed FCS(Failover Cluster Service), once you navigate to your Administrative tools and open Failover Cluster Manager(GUI to Manage your Failover Cluster), you’ll see something very similar to the below Screeshot.

Typically we expand our Cluster and navigate to our Services and Applications, Nodes, Networks to manage our SQL Servers! But you are not able to see the actual Cluster Group anywhere as shown in the below Screenshot!

Soooo….where do i get that info!!…

All you’ve to do is to Navigate to the Main Windows cluster and expand Cluster Core Resources(This will be collapsed by default) as shown below.

Once Expanded, you could see something like the below screenshot, where we can see our Cluster Group 🙂

If you are more CMD/PS person, One Simple Way to get the list of all the Groups within our Cluster from CMD is just typing “CLUSTER GROUP” from your Command Prmt! You can see the Below Screenshot from one of the nodes in my Failover Cluster.

As you can see, we still have the Core Concept of “Cluster Group”! Don’t get confused with “Available Storage” being Offline from above Screenshot, It has nothing to with your current allocated SAN Drives(Storage). I Don’t have any extra(additional) storage available in this cluster as of now(See below Screenshot to see what I mean, as you can see all of my drives are allocated to something or other), that’s the reason this is listed as Offline for now, I believe it will appear ONLINE once i create a new SAN Drive and add to this Cluster(Pls. correct me If I’m wrong.)

Soo…the Bottom Line is…We do have Cluster Group Concept, but in stealth Mode 😉