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  • 1.  Q: Storage Virtualize Policy Based HA scenario

    Posted Tue October 17, 2023 04:39 AM

    Hi all,

    Storage Virtualize 8.6.1.0 comes with Policy Based HA.
    I have a question about how the solution handles the scenario when connectivity between the two systems is lost.
    - The system will initiate a race for quorum
    - Once the race is started the partnership will be excluded.

    But what will happen when both systems can access quorum?
    Which system will continue servicing the IO's?

    Thanks.



    ------------------------------
    TMasteen
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  • 2.  RE: Q: Storage Virtualize Policy Based HA scenario

    Posted Tue October 17, 2023 08:33 AM

    In that case I believe that it's going to be a race. Whoever is able to reach the quorum first wins.

     

    Regards,

    Ian R Wright

    Client Technical Sales Engineer

    Mainline Information Systems

    Specializing in Mainframe and Open Storage, Linux, Ansible, Containers/Cloud 

     

    ian.wright@mainline.com

    301-514-0758   

     

            

     

     

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    Original Message


  • 3.  RE: Q: Storage Virtualize Policy Based HA scenario

    Posted Wed October 18, 2023 02:37 AM

    The site that loose the quorum race will get it's replicated volumes offline, but all single site volumes will continue to serve their hosts. 



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    ROGER ERIKSSON
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    Original Message


  • 4.  RE: Q: Storage Virtualize Policy Based HA scenario

    Posted Wed October 18, 2023 11:57 AM
    Hi,

    Both systems will attempt to win the quorum but with a bias as to which system wins each partition.

    In the case where both systems have unimpeded access to the quorum race, then each system will win the set of partitions where _that system is the preferred management system_, and IO and management operations will continue via that system un-interrupted. The losing system will stop serving that partition.

    Thanks,

    Carlos Fuente

    Distinguished Engineer, IBM Storage Virtualize, FlashSystem & SVC Family

    phone: +44-7795-917197

    Unless otherwise stated above:

    IBM United Kingdom Limited
    Registered in England and Wales with number 741598
    Registered office: PO Box 41, North Harbour, Portsmouth, Hants. PO6 3AU



    Original Message


  • 5.  RE: Q: Storage Virtualize Policy Based HA scenario

    Posted Mon November 06, 2023 09:46 AM

    Not really sure, but someone told me some time ago that there are several aspects that "race for quorum" is based on, such as replication direction, replication status, replication role, replication priority, and system ID. However how the system determines the highest priority based on these aspects i do not know. 



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    Mark Mather
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    Original Message


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