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  • 1.  IBM SVC Node Replacement

    Posted Mon November 04, 2024 03:06 AM

    Hi All, 

    One of our SVC clusters consists of 8x SV1 nodes and runs on 8.5.0.x
    We are looking at replacing these with 4x SV3 nodes.
    We want to do this via Node Replacement procedure.

    We want to configure 3x 64Gb FC adapters in the SV3 nodes, but these are only supported as of 8.6.0.x, and the SV1 nodes cannot have 8.6.x.x.
    Is there a way to still use the Node replacement procedure?
    At the moment we don't have enough free fc-ports to create a complete new cluster.

    Thanks.



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    TMasteen
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  • 2.  RE: IBM SVC Node Replacement

    Posted Mon November 04, 2024 03:11 AM

    Hi T, 

    Have you considered non-disruptive volume migration instead?



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    Nezih Boyacioglu
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    Original Message


  • 3.  RE: IBM SVC Node Replacement

    Posted Mon November 04, 2024 04:09 AM

    Hi Nezih,

    Volume migration could eventualy be an option, but I am dealing with hundreds of vdisks and operating systems that are not on the support list.
    So I actually hope that there is still a way to go for Node replacement.



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    TMasteen
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    Original Message


  • 4.  RE: IBM SVC Node Replacement

    Posted Tue November 05, 2024 04:42 AM

    Hello!

    Yes, this can be done using what is referred to as Paced CCU or Manual Update.

    It is a combination of these two procedures:
    IBM Docs: Updating the System manually
    and

    IBM Docs: Replacing nodes nondisruptively wiht an IBM SAN Volume Controller SV3 node


    What this does:

    The Hardware replacement procedure prep steps readies your WWPNs and Port Number and makes sure the cluster pre-reqs are met

    Then before you actually do the add node commands, you set the -pacedccu flag on the SV3 nodes, this will prevent the SV3 from downgrading it's agent code to match the cluster, it WILL downgrade it's cluster state machine to match the cluster.  This will allow you to run an 8.6.x.x version SV3 in a cluster at 8.5.0.x.


    Repeat with every node in the cluster.

    The tricky part is that you are reducing the number of IO Groups, so you will need to collapse down/remove the SV1 nodes entirely before the upgrade can be completed, and that may be difficult as you are not meant to go changing configuration during the upgrade process, which means you will need to migrate the IO Groups down first.  It is worth raising a support ticket to get walked through this, as they have been working through some pitfalls for other installs of this type.

    I hope that helps.



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    Evelyn Perez
    IBM Senior Technical Staff Member
    IBM Storage Virtualize Software Architect for SVC and FlashSystem
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    Original Message


  • 5.  RE: IBM SVC Node Replacement

    Posted Wed November 06, 2024 10:56 AM
    Edited by Kat Jarvis Fri November 08, 2024 10:31 AM

    Evelyn beat me to it  =) 


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    Philip Clark
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    Original Message