IBM FlashSystem

IBM FlashSystem

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  • 1.  Flashsystem Layer

    Posted Fri April 04, 2025 09:51 AM

    Hey Team, 

    Some of our SVC clusters have IBM Flashsystems as backend storage. It was always quite easy to get these systems under the SVC. This week we had some trouble getting this done. Afterwards it turned out that the default layer of an FS7300 was set to replication (instead of Storage).
    Is this the new default per a certain version? And is this documented somewhere?

    Thanks.



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    TMasteen
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  • 2.  RE: Flashsystem Layer

    Posted Fri April 04, 2025 11:28 AM

    From 8.6.3.0, new FlashSystems default to the 'replication' layer.

    When setting up the system, if you follow the GUI wizard to configure the system as backend storage for SVC, the layer will automatically be changed to the 'storage' layer as part of that workflow.  It sounds like you were doing the setup manually, rather than with that wizard?

    The new default is reflected in the product documentation.  Taking the 8.7.0 LTS documentation as an example:

    https://www.ibm.com/docs/en/sanvolumecontroller/8.7.0?topic=system-layers

    "A FlashSystem family system is in the replication layer by default, but the layer can be changed."

    Hope that helps.



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    Chris Canto
    Software Developer
    IBM
    Hursley
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  • 3.  RE: Flashsystem Layer

    Posted Wed May 28, 2025 10:52 AM

    Hi,

    until now we have always added STV under SVC in the some way ... recently we needed to make update SVC from  8.5.0.11 --> 8.7.0.4 we found out that this is not possible because some  controllers under SVC are in replication instead of storage mode.  

    of course affected controllers are newest 7300 because of new "default replication mode"

    situation is detectable only with test utility which is higher than :
    IBM_INSTALL_FROM_8.5_AND_LATER_upgradetest_46.10

    funny think is that  according  : 

    https://www.ibm.com/docs/en/sanvolumecontroller/8.7.0?topic=system-layers

    The system cannot provide external storage for other IBM Storage Virtualize systems. 

    but this is the way how we work so far...

     

    how to put things in order according support ?

    - Delete the MDisks from the storage pool.
    - Unmap the MDisks from the SVC.
    - Remove the existing zoning.
    - Change the layer configuration.
    - Reapply the zoning.
    - Remap the MDisks to the SVC.
    - Add the MDisks back to the storage pool.

    This procedure looks very painful since data migration is expected and it is necessary to have free capacity in the storage pool.

    I'm just curius why this new "default" was introduced ?

    Tomas



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    Tomas Kovacik
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