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3 Node Cluster Quorum RRS feed

  • Question

  • Hello,

    I have a couple of 3 node failover clusters running Hyper-V, S2D, and Storage Replica. I have set the quorum on each cluster to be NodeMajority with no witness.

    This would mean that I could lose a single node and the cluster still run correct? If I lose 2 nodes out of 3 in the cluster, that cluster should go down.

    At least that's what I thought. I can shut down two of the machines in the cluster, but the cluster keeps running. What am I missing here?

    Matt

    Friday, August 18, 2017 8:23 PM

Answers

All replies

  • Hi Mattew,

    You are correct, NodeMajority quorum you can sustain failures of half the nodes (rounding up). In you case, you can down only 1 node.

    Also, I'd like to share this two links that can improve your knowedge about the quorum modes and the news improvements on W2k16.

    Understanding Quorum Configurations in a Failover Cluster

    What's new in Failover Clustering in Windows Server 2016

    Friday, August 18, 2017 10:44 PM
  • Hi Matthew,

    >This would mean that I could lose a single node and the cluster still run correct? If I lose 2 nodes out of 3 in the cluster, that cluster should go down.

    Yes, it is.

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Monday, August 21, 2017 8:53 AM
    Moderator
  • While that does confirm how a 3 node cluster is supposed to function in terms of a Node majority quorum, it does not solve my problem.

    As I stated, I have a couple 3 node clusters with node majority quorum. When 2 nodes in the cluster are shut down, I would like for that cluster to be stopped and go offline to initiate failover to my second cluster. This is done through some scripts I have.

    The cluster is still running even after 2 nodes are shut down.


    Any ideas why this would be?


    Monday, August 21, 2017 1:36 PM
  • Turns out this is due to dynamic quorum management.

    https://technet.microsoft.com/en-us/library/jj612870(v=ws.11).aspx#BKMK_dynamic

    Monday, August 21, 2017 5:53 PM
  • Hi Matthew,

    Thanks for your feedback, if your issue has been resolved, you may mark the resolution as answer, if you have other concerns, welcome to feedback.

    Best Regards,

    Anne


    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Wednesday, August 23, 2017 6:14 AM
    Moderator
  • Hi Matthew,

    This feature is available from 2012 and above. There is also a concept of dynamic witness (2012R2 only) in which irrespective of the number of nodes in cluster, you can have a witness (disk or FS) added to the cluster. The cluster will consider the vote of the witness depending upon the number of available nodes' votes.

    https://technet.microsoft.com/en-us/library/dn265972(v=ws.11).aspx#BKMK_Witness

    Regards,

    Bala

    Wednesday, August 23, 2017 7:30 AM