About the author

Rawley Burbridge, IBM Systems & Technology Group, supports the ISV organization as the IBM Storage Solution Technology Manager for Microsoft.  He has an extensive background in virtualization and storage solutions and enjoys sharing information on these technologies through this personal blog.  The posts on this site are Rawley’s and do not necessarily represent IBM’s positions, strategies, or opinions.




4 Responses to About the author

  1. Guillaume says:

    I Rawley,

    We are currenlty in the process of buying SVC. (stretched cluster configuration)

    We just learn this history of third site for active Quorum, and for us this is a problem. So we want to put 2 quorums in the same site. We know this is not effective, but we are ready to assume this as long as we are aware of the case where this will be an issue, and we need a manual decision to move to other site.

    Case 1:
    site 1 with 1 Quorum
    site 2 with 1 Quorums & 1 active Quorum

    loss of connexions (FC & IP) between site 1 & 2 : split brain

    Site 1 –> shutdown ?
    Site 2 –> still working ?

    Case 2:
    site 1 with 1 active Quorum
    site 2 with 2 Quorums

    loss of connexions (FC & IP) between site 1 & 2 : split brain

    Site 1 –> still working ?
    Site 2 –> shutdown ?

    IBM was not able to answer us on this point, what is doing site2 which is able to see 2 non active quorums ,

    Thanks for your answer.
    Kind regards,

    • rburbridge says:


      Placing two quorums at a single site adds some risk to your deployment and you will have to follow-up with your IBM rep to submit a RPQ for it to be supported. The RPQ will give support/development a chance to review your installation and decide on a support stance. At a minimum you would want the two quorums to be on different storage systems on different power grids.

      The greatest risk to having the active and one of the standby quorums at a single site is if the entire site fails, including the active and standby quorums and the SVC node. If this happens the quorum will not fail over to the other site, and the other SVC node cannot recover.

  2. Nilton Tetsuo Ideriha says:

    How about SVC implemented as a stretched cluster and vSphere 5.0? I can’t find any report or paper about this.
    At my vision it’s not a problem because for the vSphere it’s the same disk if the SVC is implemented as a stretched cluster or a normal SVC cluster at a single site.


    • rburbridge says:

      It’s supported in vSphere 5.0 by IBM but since VMware now has a official support matrix for vSphere 5.0 with the “vMSC” category they might give some push back. My understanding is we are very close to finishing the vMSC certification.

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