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  • 1.  how to migrate multiple LPARS at once with nimadm

    Posted Tue November 29, 2022 05:33 AM

    Dear community,

    AIX 7.3 is going to be the next OS in our environment. For that I started to prepare the migration process.
    And here comes my question.
    As nimadm can only migrate one by one lpar, how do you / how would you parallelize this to migrate multiple LPAR's at once.

    I tried with "nohup" and GNU parallel, but the resource management is not very satisfying... Only one or two threads are used per process.

    Thanks for your support in advance.

    Best regards.



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    Joerg Kauke
    Unix Administrator
    COOP Switzerland
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  • 2.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Wed November 30, 2022 04:19 AM
    Hello Joerg, 

    Currently, there are no other options or alternatives besides running multiple NIMADMs with "nohup" or similar tools which should work fine, but its not the fastest solution. 

    However we would love to see this a an request for enchantment at https://www.ibm.com/developerworks/rfe/execute?use_case=changeRequestLanding
    Please, take a few minutes to submit your request and hopefully in the future we'll get this voted up and implemented in to AIX. 





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    Nayden Stoyanov
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    Original Message


  • 3.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Thu December 01, 2022 03:10 AM
    Edited by Joerg Kauke Thu December 01, 2022 05:09 AM

    Hi Nayden,

    and here is my posted "Idea"...

    https://ibm-power-systems.ideas.ibm.com/ideas/AIX-I-658

    You can vote if you would like to have that feature to... maybe in AIX 7.4  :-)

    Best regards,

    Joerg



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    Joerg Kauke
    Unix Administrator
    COOP Switzerland
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    Original Message


  • 4.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Wed November 30, 2022 08:49 AM
    Hi Joerg,

    So far we've successfully run a total of 5 parallel nimadm processes from a single NIM (E1080, CPU: VP=3, EC=1.5 Memory: 16GB). We use nimadm caching and have created a number of nimadmvgXX VGs each with a single 128GB LUN (same size as our rootvg(s)) so that the NIM client is cached to its own NIM hosted (cache) VG.

    We split the nimadm process into two sections, Phases 1-6 and Phases 7-12, as we need to re-expand the cached NIM client filesystems on the NIM itself so that during Phase 7 we have enough space to perform lpp and rpm install/upgrade work.

    1) nimadm -j nimadmvg1 -l 7302lpp_res -c <LPAR-name> -s 7302spot_res -a AIX73premigration -z AIX73postmigration -d hdiskX -P1,2,3,4,5,6 -Y

    2) Re-expand selected filesystems

    3) nimadm -j nimadmvg1 -l 7302lpp_res -c <LPAR-name> -s 7302spot_res -a AIX73premigration -z AIX73postmigration -d hdiskX -P7,8,9,10,11,12 -Y

    Performance wise, we use LPAR2RRD (https://lpar2rrd.com) to check throughput etc. and with the 5 running in parallel we hardly saw any spikes and certainly no contention. The overall runtime per nimadm process does vary, we've found, with some taking just over the hour to complete whilst others are closer to 1hr 40min and then we re-boot out of hours.

    Hope that helps.

    Regards, Steve

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    Steve Munday
    AIX, IBM i, HMC, PowerVM
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    Original Message


  • 5.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Thu December 01, 2022 03:06 AM

    Hello Steve,

    we although track our systems with lpar2rrd and nmon. But our picture is a different one. In lpar2rrd the CPU workload is at 90 to 100% while migrating and I tested how many phys. CPU are needed to get the workload under 90%...

    So, we would need one allocated processor unit per lpar to migrate. In my case, I had a system with four physical cores to migrate 4 lpars simultaneously.
    But nmon shows, that only two threads per CPU were used.

    best regards,

    Joerg



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    Joerg Kauke
    Unix Administrator
    COOP Switzerland
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    Original Message


  • 6.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Wed August 02, 2023 11:09 AM
    Edited by Matthew Opoka Thu August 17, 2023 01:30 PM

    How did your migration go?  Were you using the cachevg to offload the workload to the nim server during the package migration?



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    Matthew Opoka
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    Original Message


  • 7.  RE: how to migrate multiple LPARS at once with nimadm

    Posted Wed July 26, 2023 05:34 PM

    Migrating multiple Logical Partitions (LPARs) simultaneously using NIM (Network Installation Management) and nimadm (NIM Alternate Disk Migration) is a professional task that requires careful planning and execution to ensure minimal downtime and a smooth migration process. Below is a step-by-step guide on how to achieve this in a professional manner:

    1. Preparation and Planning:

      • Conduct a thorough assessment of the source and target systems to ensure they meet the hardware and software compatibility requirements for migration.
      • Review the current system configurations and understand the dependencies between LPARs to identify any potential challenges.
      • Create a detailed migration plan, including a rollback strategy in case of unforeseen issues during the migration process.
      • Notify all relevant stakeholders about the planned maintenance window and potential service disruptions.

    2. Backup and Validation:

      • Before starting the migration, ensure that you have a recent backup of critical data and configuration files for all LPARs to be migrated.
      • Validate the backup to ensure data integrity and correctness.

    3. Resource Allocation:

      • Ensure that there are sufficient resources (CPU, memory, disk space) available on the target systems to accommodate all the LPARs being migrated.
      • Allocate necessary resources to the target systems to support the additional LPARs during the migration process.

    4. NIM Environment Setup:

      • Verify that the NIM server is correctly set up with the latest updates and fixes.
      • Ensure that the NIM server has access to the installation images and mksysb (system backup) images required for the migration.
      • Validate network connectivity between the NIM server and both source and target LPARs.

    5. NIMADM Migration:

      • Use the nimadm command with appropriate options to perform the migration.
      • Create a NIM resource for each LPAR to be migrated, specifying the target system as the "nim_target" attribute.
      • Set the "source" attribute to the current LPAR and "spot" attribute to the desired AIX version for the target LPARs.
      • Start the migration process using the nimadm command and monitor the progress carefully.

    6. Monitoring and Verification:

      • Continuously monitor the migration process to detect and resolve any issues that may arise.
      • After migration, thoroughly test each migrated LPAR to ensure that all applications and services are functioning correctly.
      • Verify system configurations, network settings, and storage connectivity on the target systems.

    7. Rollback Plan:

      • Have a well-defined rollback plan in case the migration encounters critical issues.
      • Ensure that the rollback plan is tested and validated before starting the actual migration process.

    8. Documentation:

      • Maintain detailed documentation of the entire migration process, including the steps followed, any issues faced, and their resolutions.
      • Document the final configuration of the target systems after the migration.

    9. Post-Migration Activities:

      • Communicate the successful completion of the migration to all stakeholders.
      • Review the performance and stability of the migrated LPARs and address any post-migration issues promptly.

    10. Continuous Improvement:

    • Conduct a post-mortem analysis of the migration process to identify areas for improvement.
    • Use the insights gained to optimize and streamline future migration projects.

    Remember, the process of migrating multiple LPARs simultaneously is complex and requires a deep understanding of AIX, NIM, and system administration. It is essential to approach the task with caution, following best practices and employing the expertise of skilled professionals to ensure a successful migration.



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    bella estella
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    Original Message