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Re: [Linux-cluster] quorum



Share your configuration, please.

On 03/31/2013 02:51 AM, Prathyush wrote:
Any Idea ?


On Sat, Mar 23, 2013 at 3:41 PM, Prathyush <prathyush r gmail com
<mailto:prathyush r gmail com>> wrote:

    I have the below scenario,
    I have made the first node down the service failover to second
    node,then I switched off second node ,service again swiched to third
    node,the quorum was not lost,it adjusted automatically

    On Mar 22, 2013 9:11 PM, "Digimer" <lists alteeve ca
    <mailto:lists alteeve ca>> wrote:

        This is correct.

        Quorum needs "50% + 1" of the votes. So in Prathyush's cluster
        of 3 nodes/3 votes;

        3 / 2 == 1.5 rounded up is 2.

        So once the second node shut down, quorum was lost. With quorum
        lost, the remaining node will stop all of it's clustered
        services because it can no longer be sure what the other nodes
        are doing. For example, the other two nodes might turn back on,
        fail to connect to the one remaining node, decide they have
        quorum and start clustered services. This would lead to a split
        brain.

        If you want a 3-node cluster to work with just one node,
        consider adding a quorum disk, assuming you have a SAN. This
        would add 2 votes to the cluster. So the new math would be;

        5/2 == 2.5 rounded up to 3.

        The quorum disk would give it's two votes to the remaining
        single node for a total of 3 votes, thus giving it quorum and
        allowing it to operate on it's own.

        digimer

        On 03/22/2013 03:16 AM, emmanuel segura wrote:

            Hello

            If i understand well, you 3 node(3 total votes) and you
            poweroff 2, 3 -
            2 = 1(quorum loss) remain less 50% of votes

            can you show your config and your log, without it's so hard
            help you

            Thanks

            2013/3/22 Prathyush <prathyush r gmail com
            <mailto:prathyush r gmail com> <mailto:prathyush r gmail com
            <mailto:prathyush r gmail com>>__>

                 HI,


                 I have 3 node  cluster with 1 vote each ,and  decided
            to shut down
                 the 2 nodes for  maintenance .
                 When a proper power off /init 0 given to two of the
            nodes ,i never
                 loses the quorum
                 When i am making  force power off (switching off the
            power/pulling
                 the power cable) quorum  was lost and services failed
            in the third node.
                 why this is happening... any idea
                 --
                 /*Regards,
                 Prathyush*/



        --
        Digimer
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--
/*Regards,
Prathyush*/




--
Digimer
Papers and Projects: https://alteeve.ca/w/
What if the cure for cancer is trapped in the mind of a person without access to education?


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