File and Object Storage

File and Object Storage

Software-defined storage for building a global AI, HPC and analytics data platform 

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  • 1.  Storage Scale cluster using storage-based replication

    Posted Wed January 14, 2026 10:58 AM

    Hello, everyone.

    Does anyone have experience configuring an active-passive IBM Storage Scale cluster using storage-based replication? I have read the IBM documentation, and there is very little information on this topic, 
    Are there more documentation or redbooks about this topic?
    Any comment, hint will be helpfull.
    Thanks in advance.



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    Alejandro Carmona
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  • 2.  RE: Storage Scale cluster using storage-based replication

    Posted Wed January 14, 2026 06:50 PM

    Hi Alejandro,

    Can you please provide some context on what you are trying to achieve?

    Are you trying to build an offline DR cluster that you "turn on" in the event of an emergency, that uses some form of san based replication to replicate the luns between the production and DR cluster but you only turn on the DR cluster when you want to use it? 

    Are you trying to use SAN based replication for Async replication between two clusters but not have any workload attached to the 2nd cluster

    Are you looking for something else? 



    ------------------------------
    Andrew Beattie
    Technical Sales Specialist
    IBM Australia / New Zealand
    P. +61 421 337 927
    E. Abeattie@au1.ibm.com
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  • 3.  RE: Storage Scale cluster using storage-based replication

    Posted Thu January 15, 2026 04:02 AM

    We are trying to build an offline DR cluster.

    We have two sites, one primary and one secondary. At the moment, I only have one scale cluster at the primary site, with Hitachi storage array as backend. The volumes from the storage array are replicated at the secondary site. 
    The part that causes me concern is when a file system needs to be expanded.
    At the moment, what we do is:
    1.- Create a volume.
    2. Add it to a consistency group so it can be replicated.
    3. Assign the volume to the host.
    4. Scan the new LUN from the host.
    5. Add the LUN to the file system.

    I'm not quite sure what the workflow would be for expanding a file system in a disaster recovery environment.



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    Alejandro Carmona
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  • 4.  RE: Storage Scale cluster using storage-based replication

    Posted Thu January 15, 2026 03:05 PM

    Hi Alejandro,

    This documentation link provides the details of how to achieve the solution you describe:
    https://www.ibm.com/docs/en/storage-scale/6.0.0?topic=cluster-setting-up-active-passive-storage-scale-configuration

    The key thing to keep in mind is the following:

    The peer clusters must always see a consistent image of the configuration state for the mirrored file system; the configuration state is contained in the mmsdrfs file. After the initial creation of the file system, all subsequent updates to the local configuration data must be propagated and imported into the peer cluster. Run the mmfsctl syncFSconfig command to resynchronize the configuration state between the peer clusters after each of these actions in the primary IBM Storage Scale cluster:

    • Addition of disks through the mmadddisk command
    • Removal of disks through the mmdeldisk command
    • Replacement of disks through the mmrpldisk command
    • Modifications to disk attributes through the mmchdisk command
    • Changes to the file system's mount point through the mmchfs -T command

    To automate the propagation of the configuration state to the recovery cluster, activate and use the syncFSconfig user exit. Follow the instructions in the prolog of /usr/lpp/mmfs/samples/syncfsconfig.sample.



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    Piyush Chaudhary
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