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  • 1.  Create GAD Volume for 2 Node Cluster and care about ALUA

    Posted 07-26-2022 10:24
    This example :
    I have 2 rooms
    Room A and Room B.

    Room A contains : 1 x VSP A and 1 x Server 1
    Room B contains : 1 x VSP B and 1 x Server 2

    Now I want to create a GAD volume accessed by Server 1 and 2.
    And I expect to get this ALUA setting:
    Server 1 -> access Volumes on VSP A as active-optimized
    Server 1 -> access Volumes on VSP B as active-NONoptimized
    Server 2 -> access Volumes on VSP A as active-NONoptimized
    Server 2 -> access Volumes on VSP B as active-optimized

    And the next level of demand is that on VSP A and VSP B I want to use the same Front End Storage Ports.
    E.g. to let it simple : CL3-A and CL4-A should be used on VSP A and VSP B to present the volumes for Server 1 and 2.

    How to do this in OpsCenter Administrator ?

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    Sven Kirsten
    Systems Engineer
    SVA System Vertrieb Alexander GmbH
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  • 2.  RE: Create GAD Volume for 2 Node Cluster and care about ALUA
    Best Answer

    Posted 07-28-2022 03:40
    Hello Sven

    When you create a volume with High Availability in Administrator, on the attach screen you have the ability to select 'ALUA' volumes. This is the first step, the rest you specify during the pathing. Dotted lines are Active-Non Optimized and solid lines are typically Active-Optimized.

    Example of DC1(Production Site) and DC3(DR Site Setup):


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    William Jansen van Nieuwenhuizen
    Hitachi Vantara
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  • 3.  RE: Create GAD Volume for 2 Node Cluster and care about ALUA

    Posted 07-28-2022 06:18
      |   view attached
    Thank you very much William.

    There is one mistake I did. When I have 2 servers located in Room A and Room B , I can join this server 2 at the beginning of the process of "create GAD volume" or later as "secondary" server. Until now I saw there no difference. But there is a huge difference. Only when I join the server 2 located in Room B later as "secondary" then I have the chance to select the non-preferred path individual.

    See the attached PDF.

    And that is the reason why I love SAM4H. 
    In SAM4H you assign each storage array and each server a location.
    And then in each case you want to build storage for these server,  you do not need to care about ALUA and non-preferred information. SAM4H is setting it in the background for you. No risk to forget it or to set it wrong in the procedure "create new GAD volume".  If the server and the storage array are in the same location, then of-course its preferred path. And if the storage array is in the other location, then of-course its non-preferred. If you build a new GAD volume, in SAM4H there is no need to give this information about ALUA and preferred/non-preferred again and again, SAM4H is already aware about this and it reduces the complexity to a minimum - really cool stuff.

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    Sven Kirsten
    Systems Engineer
    SVA System Vertrieb Alexander GmbH
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    Attachment(s)



  • 4.  RE: Create GAD Volume for 2 Node Cluster and care about ALUA

    Posted 08-02-2022 07:50
    Hello Sven,

    Just curious, why not using HMO78 at hostgroup instead of ALUA to set preferred path?

    Best regards,
    Geert Scholten

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    Geert Scholten
    Systems Engineer
    Cooperatieve Rabobank U.A.
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  • 5.  RE: Create GAD Volume for 2 Node Cluster and care about ALUA

    Posted 08-03-2022 09:15

    Sven, my olde friend !

    Given our past history, are you referring to "cluster" in the HNAS sense? If so, the answer is HNAS does not support ALUA, we use HMO 78 (using ALUA would take rework of the HNAS SCSI driver and is a roadmap item).

    HDRS is your starting/landing point for HNAS stretched clusters.



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    Albert Hagopian
    Software Development Engineer - Specialist
    Hitachi Vantara
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  • 6.  RE: Create GAD Volume for 2 Node Cluster and care about ALUA

    Posted 08-03-2022 16:55
    Hi Al,

    I love it to hear from you ;-)
    I hope you are well and working hard to make the best product in the NAS world.
    Here in this Post its not HNAS related, its just how to do it in OpsCenter.
    The Video from William explains it really really good.

    Thanks a lot Al and I hope to get a special deep dive training around HNAS from you ;-)

    all the best
    Sven

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    Sven Kirsten
    Systems Engineer
    SVA System Vertrieb Alexander GmbH
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