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  • 1.  Need help understanding the nimadm -H command

    Posted 06/10/26 02:24 PM

    Hello,

    I'm trying to understand what the nimadm -H command does in AIX. I've looked through the man pages and some online resources, but I haven't been able to find a clear explanation. Could anyone please provide more details on the purpose and usage of this command?

    Any insights or pointers to documentation would be greatly appreciated. Thanks in advance for your help!



  • 2.  RE: Need help understanding the nimadm -H command

    Posted 06/11/26 03:56 AM

    Hi Don

    I have also seen SMIT add that flag when performing alternate disk migrations, but we have always omitted it when doing AIX upgrades and it worked just fine. (NB: All our LPARS are exclusively HMC-managed anyway)

    the -H tells NIM that the LPAR is HMC-managed and it should be aware of this. It then effectively communicates statuses with the HMC and kind of closes that gap.

    If you have a mixed setup where you have NOVA-managed and HMC-managed LPARS this is maybe a good idea to include it. (I wonder if this is also something to consider for PowerVC-managed vm's which we also have)

    Since 2023 we have started automating with Ansible so I must go check if the ibm.power_aix collection actually includes -H flag.

    I will let you know if I find anything.

    Regards

    Anwar



    ------------------------------
    Regards

    Anwar Williams
    ------------------------------



  • 3.  RE: Need help understanding the nimadm -H command

    Posted 06/15/26 04:18 AM

    Hi Don

    I think we have to establish which version of AIX you using as it appears the command has changed between AXI versions.

    https://www.redbooks.ibm.com/redbooks/pdfs/sg247296.pdf

    This old redbook i found says the -H flag is used for help and to indicate the command was invoked using SMIT.  (See Section 4.6.3 page 273 but this I think is AIX 5.3 specific)

    Note: When nimadm is run via SMIT, you will notice that an undocumented flag (-H) appears in the command line (press F6). /usr/sbin/nimadm -H -cLPAR4 -lLPP_53_ML4 -sSPOT_53_ML4 dhdisk1 -jnimvg -Y
    This -H flag is used internally (passed between the SMIT scripts to nimadm) so that nimadm knows it is called via SMIT. This will then change the way some messages appear. For example, a message such as: Choose this menu option would be shown as: use this flag for SMIT versus the command line.

    Even this explanation below seems odd because we have long stopped using rsh/hosts.equiv, we strictly use nimsh

    The -H flag in the nimadm command forces the utility to use host-based authentication (like standard remote shell protocols rsh or ssh) instead of the default NIM Service Handler (NIMSH). What -H Dictates in Your Command Communication Layer: When you use -H, nimadm bypasses nimsh (port 1058/1059) and relies entirely on your master server's ability to run remote commands directly on the client. Pre-requisites: For -H to work successfully, standard network communication environments like /etc/hosts.equiv or .rhosts must be pre-configured to allow unprompted remote access between the NIM master and the client. If -H is omitted, the command defaults to secure nimsh communications for executing the migration phases on the targeted LPAR.

    Ultimately, I think it is an indicator that the command was invoked via SMIT, on its own it does nothing.

    Hope this helps.



    ------------------------------
    Regards

    Anwar Williams
    ------------------------------

    Original Message


  • 4.  RE: Need help understanding the nimadm -H command

    Posted 06/11/26 03:57 AM

    I reviewed the official IBM AIX 7.3 documentation for the nimadm command and could not find any reference to a -H flag. The documented command syntax and available parameters do not include this flag.

    IBM's official documentation for the nimadm command can be found here:
    https://www.ibm.com/docs/en/aix/7.3.0?topic=n-nimadm-command

    According to the current IBM AIX 7.3 command documentation, -H is not a documented nimadm flag.

    Could you please share where you have seen this option used? for example, was it in a  technote, IBM documentation, or command output?

    Thank you



    ------------------------------
    Anas AlSaleh
    IBM Power Systems Software Specialist
    Saudi Business Machines ( SBM )
    Riyadh
    ------------------------------



  • 5.  RE: Need help understanding the nimadm -H command

    Posted 06/11/26 05:30 AM
    Edited by Zaki Jääskeläinen 06/11/26 07:49 AM

    nimadm is a script and it looks like the '-H' flag is only to tell the script that it was called from SMIT and when doing a migration, complain if new license agreements were not accepted.



    ------------------------------
    Zaki Jääskeläinen
    ------------------------------



  • 6.  RE: Need help understanding the nimadm -H command

    Posted 06/15/26 12:22 PM

    Yes, it's an internal flag. That's why it wasn't documented, as we need to differentiate whether it was executed via CLI or SMIT.



    ------------------------------
    Srikanth Thanneeru
    ------------------------------

    Original Message


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