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Is FlashSystem's migration function available when only storage is being migrated?

  • 1.  Is FlashSystem's migration function available when only storage is being migrated?

    Posted Thu January 19, 2023 05:13 AM
      |   view attached
    We are planning to replace only the storage with FlashSystem 9500 as the A9000 is out of maintenance.
    According to Redbook, in this case, I think it is a full backup/full restore on a tape device or a LUN-to-LUN movement with the STRASPBAL command.
    Is the FlashSystems migration function like the attached file available?

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    ATSUSHI NAKATA
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    Attachment(s)

    pptx
    Migration Function of FlashSystem.pptx   1.61 MB 1 version


  • 2.  RE: Is FlashSystem's migration function available when only storage is being migrated?
    Best Answer

    Posted Thu January 19, 2023 08:29 AM
    Edited by Satid Singkorapoom Fri January 20, 2023 07:04 AM
    Nakata-san

    I used the following method in the past with several IBM i customers when moving from one SAN box to a new SAN box. (This should work with migrating from internal disks to SAN or vice versa.) The last case I did was in 2019 migrating from DS8K to V7K with flash disks for POWER8 IBM i server. Here are generalized action steps for the migration :

    1. Without touching existing LUNs and fiber connection to the old SAN box, connect IBM i server to the new SAN box.  You need to use a different physical FC or vFC to connect the new SAN box because you will eventually (in step 8 below) need to change to a new load source disk/LUN unit which must be on a different FC or vFC card.
    2. Run WRKDSKSTS, to check that IBM i sees all new LUNs, all of which are designated as unit number zero.
    3. With SRTSST, add all new LUNs except one LUN (the first one in the list) to the existing IBM i disk pool (ASP). The one LUN not added is still in non-configured status and will be use as the new Load Source Unit (LSU) disk.  This step can take a long time. 
    4. When all the new LUNs (except one) are added to the ASP, exit SST and then run STRASPBAL to mark all old LUNs (EXCEPT unit number 1 - the current LSU) as *ENDALC and run STRASPBAL *MOVDTA at *HIGH priority. This runs on-line and can take a long time.   Use CHKASPBAL to check this progress.
    5. When *MOVDTA finishes, the next phase will be done while the system is off line.  At a proper planned subsequent date-time (no need to be right after the previous step), right before the next action step, it is recommended that the customer performs save-entire-system and proceed when finished.
    6. From HMC, change IPL mode of IBM i server/LPAR to MANUAL and then IPL the system and use the console session from HMC.
    7. When Dedicated Service Tool (DST) menu appears, set IPL mode back to NORMAL from HMC.
    8. In HMC, change the Load Source tagging of the server/LPAR to the new FC that connects to the new SAN box by Edit the LPAR profile --> Tagged IO tab --> Select the FC from Load Source field as shown below.  (Client Fibre Channel = vFC.)
    9. Back to HMC console session, from DST menu select 3. Use Dedicated Service Tools (DST) --> 4. Work with disk units --> 2. Work with disk unit recovery --> 9. Copy disk unit data --> Select disk unit number 1 from the OLD LUN  --> Select the only one non-configured unit (the only new LUN you will see) --> Press F10 on the subsequent screen of "Problem Report" --> Press enter to start Load Source Copy process and observe the progress. This can take long.
    10. When Load Source copy finished, the LPAR automatically IPL from the new LSU LUN.  WRKDSKSTS will show the old LSU as disk unit number zero.
    11. Use SST to remove the old LUNs out of IBM i ASP on-line.  STRSST --> 3. Work with Disk Units. --> 2. Work with Disk Configuration --> 12. Work with Removing Units From Configuration --> 3. Remove Units from Configuration --> Select ALL old LUNs for removal from ASP --> Confirm the removal
    12. Select option "2. Display status of remove operation" from the Work with Removing units From Configuration screen to check the progress. This can take short or long depending on how high the remaining "% Used" is for the old LUNs and how many old LUNs there are.
    13. When disk removal from ASP finishes, run WRKDSKSTS and make sure that all old disk units LUN become unit number zero. 
    14. Proceed with the logical and physical removals of the old SAN box connection from IBM i system/LPAR.
    Let me know if you have further question.




      ------------------------------
      Right action is better than knowledge; but in order to do what is right, we must know what is right.
      -- Charlemagne

      Satid Singkorapoom
      ------------------------------

      Original Message


    1. 3.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      IBM Champion
      Posted Fri January 20, 2023 07:32 AM
      Thank you for the details.
      I used a process very similar to this when migrating from one internal expansion unit filled with one type of disks to another internal expansion unit filled with newer models of disk.  It was a very lengthy process and I was pretty sure I could have saved/restored and did it in less time.
      However, I am in the process of migrating from P8&P9 with internal storage to P10's on a SAN and I am intrigued.

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      Robert Berendt IBMChampion
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      Original Message


    2. 4.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      Posted Thu January 19, 2023 08:09 PM
      Edited by Satid Singkorapoom Fri January 20, 2023 06:28 AM
      Dear Nakata-san

      I hope you see the disk migration process above easy enough as it does not require save entire system and restore entire system at all.  And most of my provided process above is done on-line except the step of load source disk copy which takes about 1 hour or less for flash disk system.    

      But I just found this IBM i storage support metrix : https://www.ibm.com/support/pages/system/files/inline-files/iExternalStorageMatrix-20220809.pdf but I do NOT see FS9500 indicated as being supported by IBM i (only see FS9100 and FS9200).  This matrix was produced in August last year and may not contain up to date info.

      You should also use IBM System Storage Interoperation Center (SSIC) web site to check if FS9500 is currently supported by IBM i or not.

      ------------------------------
      Right action is better than knowledge; but in order to do what is right, we must know what is right.
      -- Charlemagne

      Satid Singkorapoom
      ------------------------------

      Original Message


    3. 5.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      Posted Fri January 20, 2023 09:26 AM

      If the A9000 and FS9500 are on the same SAN fabric:

      Configure Metro Mirror replication of volumes from A9000 to FS9500 via FC replication.
      Add zoning from HOST LPAR to FS9500
      Once volumes are in sync
      Power off LPAR
      End Replication and enable target volumes
      map FS9500 volumes to the HOST LPAR
      IPL LPAR

      This provides a shorter outage window than the load source migration plus has the benefit of if there is an issue the original volumes are still available on the A9000. 
       



      ------------------------------
      Steve Pavlichek
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      Original Message


    4. 6.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      Posted Fri January 20, 2023 06:27 PM
      Edited by Satid Singkorapoom Sun January 22, 2023 07:11 AM
      Dear Steve

      Your proposed method is quite interesting as it appears to need very few actions in IBM i. But may I ask if you ever had any first-hand experience in using your described method successfully with any IBM i customer?  If so, what was the typical downtime you encountered and whether there was any potential unexpected issue to be aware of?   

      For my method provided above, I used it for the last time in my career in 2019 for a customer who had about 30 small IBM i LPARs (serving many world wide branches) using NPIV from dual VIOS and it fortunately worked smoothly for all LPARs without any unexpected issues whatsoever in the entire procedure I described above. I did the migration for 3-4 LPARs at a time each weekend.

      ------------------------------
      Right action is better than knowledge; but in order to do what is right, we must know what is right.
      -- Charlemagne

      Satid Singkorapoom
      ------------------------------

      Original Message


    5. 7.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      Posted Sat January 21, 2023 08:53 AM
      I use this method frequently and is my preferred method for replacing external storage. Less risk as original volumes are still available and less downtime than load source migration. Total time is less than 10 minutes to make changes on storage plus time to power down and IPL.

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      Steve Pavlichek
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      Original Message


    6. 8.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      Posted Sun January 22, 2023 07:10 AM
      Edited by Satid Singkorapoom Sun January 22, 2023 07:27 AM
      Dear Steve

      Thanks for your confirmation which serves as a very good news for all IBM i customers using IBM SAN disk.

      Nakata-san

      I suggest you should take note of Steve's method which definitely requires much less actions in IBM i than mine.

      ------------------------------
      Right action is better than knowledge; but in order to do what is right, we must know what is right.
      -- Charlemagne

      Satid Singkorapoom
      ------------------------------

      Original Message


    7. 9.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      IBM Champion
      Posted Mon January 23, 2023 09:29 AM
      Thank you.  I wondered about how SAN migrations were done and how disruptive they were.  This really helps my confidence level.
      We're installing our first SAN in under 2 weeks.

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      Robert Berendt
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      Original Message


    8. 10.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      Posted Mon January 23, 2023 11:00 AM
      I can confirm that Steve's method is the preferred method to migrate from one SAN to another when SAN replication is an option.

      Do the replication and mapping changes as suggested by Steve.  When you do the first IPL onto the replicated volumes, do it as a Manual IPL and use DST (hardware service manager) to remove non-reporting hardware.  While in DST, you will also want to use the multipath resetter to adjust the O/S error reporting to the new path structure:  https://www.ibm.com/support/pages/reducing-or-removing-paths-multipath-lun.  I also verify that I have the desired number of paths on the new disk.  Options vary between SST and DST, but you are looking for something along the lines of Work with disk units->Display Disk->Display disk paths.

      Replication is preferred over the STRASPBAL method when you can do storage replication because it is much more efficient, is reversible, and minimizes downtime for the customer.

      Given a choice for migration, I would select:  

      1) SAN based replication
      2) STRASPBAL (Satid's process is by far the best I've ever seen for that)
      3) Save/Restore

      On the subject of FS9500 support, I can't speak directly to whether it is supported, but I can say that I have recently configured FS9500 on IBMi using LPAR owned fiber channel adapters and SAN switch fabric with 100% success.

      ------------------------------
      Vincent Greene
      IT Consultant
      Technology Services
      IBM
      Vincent.Greene@ibm.com


      The postings on this site are my own and don't necessarily represent IBM's positions, strategies or opinions.
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      Original Message


    9. 11.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      Posted Mon January 23, 2023 08:32 PM
      Edited by Satid Singkorapoom Mon January 23, 2023 09:25 PM
      Dear Vincent

      >>>>  While in DST, you will also want to use the multipath resetter to adjust the O/S error reporting to the new path structure: https://www.ibm.com/support/pages/reducing-or-removing-paths-multipath-lun.  <<<<

      What a serendipity this Multipath Resetter is :-)   

      In 2019, my colleagues and I did SAN migration from DS8K to V7K with SSD for a customer with about 30 IBM i LPARs. In the early stage of the engagement, the customer noticed that, in each IBM i LPAR, there were 4 paths to the new V7K while the number of path to DS8K was just  2 and he asked my storage colleague to reduce from 4 paths to 2 for V7K. I found out in a storage redbook much later that all StorWize used 4 paths as its default which is different from the old DS8K but since the change was already made, the customer did not care to ask to revert back to 4. I guessed that since V7K always produced 4 paths to IBM i, my colleague had to reduce them manually to 2 for each IBM i LPAR - I realized later that this left 2 dangling unused paths.

      Then what happened was that I started to notice that all IBM i LPARs (after connecting to the new V7K with 2 paths) took about 5 minutes longer to IPL which was a frustration for me. From HMC, I saw that IPL process got stuck at an SRC code that indicated "DASD Check" function for about 5 minutes before proceeding - this SRC never got stuck before with DS8K.  I made this observation to the team and guessed that this might be because of the dangling unused paths and tried to find a way to address it but it was in vain as we were too busy with the workload as there were so many LPARs to work on. The project finished towards the end of 2019 and we forgot to pursue on this issue but I knew it was not a serious problem as the customer rarely IPL their LPARs in a year, if at all. 

      Now, having read your post above about this Multipath Resetter, it dawns on me that this must be the solution I was looking for!   

      Thanks for your post that helps me serendipitously stumble upon the piece of missing information I looked for.  Now, I can die with my eyes closed ;-)


      By the way, your provided hot link URL above includes the full stop at its end which causes the hot link to become broken. Please remove the full stop out of the hot link to make it work.

      ------------------------------
      Right action is better than knowledge; but in order to do what is right, we must know what is right.
      -- Charlemagne

      Satid Singkorapoom
      ------------------------------

      Original Message


    10. 12.  RE: Is FlashSystem's migration function available when only storage is being migrated?

      Posted Tue January 24, 2023 02:30 AM
      Thank you all for the great information!

      I was worried with the IBM i support about SAN based replication in the storage migration proposal.
      However, I understand that it is not a problem in terms of support because we will just use remote replication in the DR system in the same way during storage migration in the local environment.


      Dear Satid-san,

      The work performed in 2019 was very beneficial to me to better understand the documents in the Redbook with screen copies.
      Thank you very much!
      By the way, I understand that IBM i support for the FS9500 is not a problem, as I have confirmed support for the FS9500 on both IBM i storage support metrix and SSIC.
      I was confused at first too, but FS9500 was listed at the bottom of the list.



      ------------------------------
      ATSUSHI NAKATA
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      Original Message