Rob’s Ragg…. Tech Talk & Cool Toys for Grown up Boys & Girls

All of your Cluster Nodes have to be the Same Installation Method

I’m working on a Microsoft Hyper-V Server cluster and wanted to play “What if”, so I added one of my Hyper-V Servers to my existing Windows Hyper-V Cluster.  I was able to add it, but it failed when I then ran the validation tests on my cluster:

Validate Operating System Installation Option

Validate that the operating systems on the servers use the same installation option (full installation or Server Core installation).

Validating that all servers have the same operating system installation type (Full/Core).

Node	Installation Type
c4.	Full Install
dc1.	Full Install
hv1.	Core Install

This is a fatal error under the System Configuration Section.  I get a lot of warnings in my test scenarios and can work past them, but errors like this will prevent your cluster from being a Supportable Cluster, so I’d caution against deploying a mixed installation cluster in production.

I’m one that wants to understand the why of a situation, but I don’t have an explanation for this one… yet.  I’m looking around to see if I can find any detail on this situation.  If I find anything I’ll share it, but for now, please take note that you cannot mix Full Installations and Core Installations, or Full Installations with the Microsoft Hyper-V Server, if you want to maintain a supportable cluster.  

I have an update on the why.  The reality is that a Server Core installation does not support all of the roles and features that a full installation supports, so we found it made more sense to require similar installs for our clusters.  If we have a mixed installation there could be scenarios where some nodes of your cluster cannot support a failover event, so we chose to require similar installations.  While it is possible to make a mixed configuration work, the bottom line is that our supported configuration, the configuration that puts you in the best position for success, is to ensure that all of the installations within your cluster be either full, or core, not a mixed configuration.

Until next time!

Rob