Hello Siva,
In principle, it is easier to migrate LPARs with AIX at OS level, as Nezih mentioned. AIX can create three data copies and normally this is transparent for the applications and you can plan a necessary reboot of the partitions sensibly, but with Power Servers with AIX there are many variants of how a storage migration can be carried out. This depends on whether one VIO or several VIO partitions are used or whether VSCSI or NPIV is used. The order in which our PSO team would perform a migration for customers:
1. AIX migration
2. storage virtualization - StorWize under FlashSystem
3. NDVM - Here there were and are restrictions depending on the operating system, see "Configuration Limits and Restrictions for IBM Spectrum Virtualize" matching the firmware of the StorWize. Example: 8.4.x
Regarding your question:
As with the host connection, you need a redundant connection. You do not need to disconnect anything for this. The cabling of the FlashSystem is identical to that of the StorWize. Zoning is important here.
Consider the new flash system as a host.
StorWize is the storage for the FlashSystem and the hosts.
1. Storwize requires the storage layer
2. the FlashSystem requires the replication layer
3. create zoning that makes the FlashSystem redundant as a host (optimally each controller of the FlashSystem should be seen as redundant by each controller of StorWize) - use the physical wwpns of the flashsystem and the wwpns of the storwize which already used in the existing host zoning.
4. create zoning of the Hosts-FlashSystems
5. transfer the host configuration of the StorWize to the FlashSystem
6. test whether the connection works - e.g: Test LUN
So now the important thing, during the host LUN migration as such, the host, in this case the AIX or VIO partition, must not have simultaneous access to the image mode disk as to the old system. This would destroy the data.
Therefore:
1. shut down the partition
2. remove host mapping on the StorWize
3. configure image mode, maybe incl. vDisk Mirror
4. add host mapping on the FlashSystem
5. start partition
6. pray, no seriously now the partition should start again if everything was done correctly
You can also take a look into this IBM Redbook Implementation Guide for IBM Storage FlashSystem and IBM SAN Volume Controller
Best regards
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Patrik Groß
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Original Message:
Sent: Thu December 07, 2023 11:43 AM
From: SIVA C
Subject: MIGRATION OF DATA FROM STROWIZE 5000 TO FLASH SYSTEM 5200 - HAVE SOME QUERIES.
I am using IBM storwize 5000 with 5 AIX servers connected in FC Fabric.
A new flash system 5200 was procured and I have to migrate all data from 5000 --> flash system.
AS PER " https://www.ibm.com/docs/pt-br/flashsystem-5x00/8.4.x?topic=m-migrating-data-by-using-fibre-channel-connections-4", ALL THE HOSTS MUST BE DISCONNECTED FROM 5000 BEFORE MOVING TO 5200.
Questions :
1. Is is mandatory that all fc ports of 5000 to be connected / zoned with 5200 ?
2. Is it mandatory that all hosts connected to 5000 to be offlined at the same time ? Or can the migration be done host by host ?
3. There are 8 fa ports in 5000. I want to use (a) 4 fa ports for host connection in 5000 (b)4 ports in 5000 zoned with 4 ports in 5200 for migration. Is it ok ? The same 4 ports of 5200 , i am planning to zone with the hosts. ( I have only 12 ports licensed on my switch)
4. Can the same fa ports be shared between hosts and storage-storage connection ?
If anyone has done such a migration , requesting inputs / guidance.
Thank you
Siva C
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SIVA C
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