Recently, I had to do a "Host-based" storage migration from old IBM storage to a new different-brand flash storage on AIX 7.2 server resides on Power 9 and Power 10 respectively.

As y'all know , it's risky when you migrate disks between different-brand storages as you need a related-storage driver " non-native" or third party tools to make it happen.

There are several ways to do that and it depends on how you mapped your disks from storage to servers ( vscsi or NPIV ).

From my last experience , here is some tips for host-based storage migration for "NPIV" mapped disks:

1- From SAN switch,
create a zone containing the server WWPN and new storage WWPN.

2- From new SAN storage,
add and define the host WWPN to the new storage.

3- Check your current system disks and VG's.

4- Make sure to take a fresh system clone before proceed 😁.

5- Install the new storage driver to avoid seeing the disks multiple times. *some drivers needs a system reboot*

6- From new SAN storage ,
create new disks same as old disks and mapped it to the host . " it's perferred to create one-by-one VG disks " .
🌟I like to start migration with data VG's and then rootvg🌟

7- Discover the new disks :
# Cfgmgr
# Lspv or lsmpio -qa
* some storages have their own driver commands*

8- Migrate the current data VG's from old storage disks to new storage disks by using LVM as shown on the following commands:
# Extendvg <vg_name> <hdisk_new>
# mirrorvg -S <vg_name> <hdisk_new>
# syncvg <vg_name>
# lsvg -l <vg_name> ; to make sure all LV's are synced
# unmirrorvg <vg_name> <hdisk_old>
# reducevg <vg_name> <hdisk_old>
# rmdev -Rdl <hdisk_old>

From old storage side , Unmap old disks.

9- migrate rootvg from old storage disk to new storage by using LVM as shown on the following commands:
# Extendvg rootvg <hdisk_new>
# mirrorvg -S rootvg <hdisk_new>
# syncvg <vg_name>
# lsvg -l rootvg
# unmirrorvg rootvg <hdisk_old>
# migratepv <hdisk_old> <hdisk_new>
# bosboot -ad <hdisk_old>; to create boot image for new disk
# bootlist -m normal <hdisk_new>
# bootlist -m normal -o ; to see your booting order
# savebase
# reducevg rootvg <hdisk_old>
# rmdev -Rdl <hdisk_old>

From old storage side , Unmap old disks.

*reboot your system and make sure all filesystems are up and mounted*

10- Finally, make sure to take a new clone on new storage disk and delete the old one. 😁

Hopefully this article helps you to migrate your storages faster .

------------------------------
Hashem Al-Qaisi
Senior Systems Engineer
Jordan Business Systems
------------------------------

On Thu, Nov 06, 2025 at 12:12:40PM +0000, Hashem Al-Qaisi via IBM TechXchange Community wrote:
> Recently, I had to do a "Host-based" storage migration from old IBM
> storage to a new different-brand flash storage on AIX 7.2 server
> resides on Power 9 and Power 10 respectively.

This is a pretty comprehensive list. I have a few suggestions.

You don't need to make 1:1 LUN replacements. The new storage may
prefer fewer larger LUNs, or more smaller LUNs. Consider what the
final VG layout should be.

Make sure you're already using Scalable VG's. Make sure that your VG
has enough space to double the number of PP's (VG factor for original
and Big VG's). This will impact whether you can mirror. You cannot
change the PP size when doing a PV migration in the VG.

Confirm that the HBAs and new hdisks have the correct best practice
attributes (ie: queue_depth, algorithm, max_xfer, etc). Do this before
adding them to the VG. You might also consider using empty HBA ports
for the new LUNs vs the old. Used to be that drivers didn't like to
share the HBA port across different storage. That also means you can
easily customize the HBA attributes.

If you are booting from SAN and migrate the rootvg, test this
thoroughly on a nonprod system. I had major problems at a customer
using Powerpath years ago that no matter what steps were taken,
rebooting after migration just hung. We always had to restore from
mksysb to get a bootable OS.

You might consider grabbing an extra LUN for rootvg, and doing a
alt_disk_install. That way you have an offline bootable copy. This
also works well for potential rollback during AIX upgrades.

Thanks.

------------------------------------------------------------------
Russell Adams Russell.Adams@AdamsSystems.nl
Principal Consultant Adams Systems Consultancy
https://adamssystems.nl/

Dealing with the boot from SAN issue now.

There are instructions and tools available from Dell-EMC.

Look at this - Dell Technologies Host Connectivity Guide for IBM AIX

One complication we are facing is making sure we have valid snapshots through the migration process.

------------------------------
Alexander Pettitt
------------------------------

Original Message:
Sent: Thu November 06, 2025 09:48 AM
From: Russell Adams
Subject: AIX Storage Migration

On Thu, Nov 06, 2025 at 12:12:40PM +0000, Hashem Al-Qaisi via IBM TechXchange Community wrote:
> Recently, I had to do a "Host-based" storage migration from old IBM
> storage to a new different-brand flash storage on AIX 7.2 server
> resides on Power 9 and Power 10 respectively.

This is a pretty comprehensive list. I have a few suggestions.

You don't need to make 1:1 LUN replacements. The new storage may
prefer fewer larger LUNs, or more smaller LUNs. Consider what the
final VG layout should be.

Make sure you're already using Scalable VG's. Make sure that your VG
has enough space to double the number of PP's (VG factor for original
and Big VG's). This will impact whether you can mirror. You cannot
change the PP size when doing a PV migration in the VG.

Confirm that the HBAs and new hdisks have the correct best practice
attributes (ie: queue_depth, algorithm, max_xfer, etc). Do this before
adding them to the VG. You might also consider using empty HBA ports
for the new LUNs vs the old. Used to be that drivers didn't like to
share the HBA port across different storage. That also means you can
easily customize the HBA attributes.

If you are booting from SAN and migrate the rootvg, test this
thoroughly on a nonprod system. I had major problems at a customer
using Powerpath years ago that no matter what steps were taken,
rebooting after migration just hung. We always had to restore from
mksysb to get a bootable OS.

You might consider grabbing an extra LUN for rootvg, and doing a
alt_disk_install. That way you have an offline bootable copy. This
also works well for potential rollback during AIX upgrades.

Thanks.

------------------------------------------------------------------
Russell Adams Russell.Adams@AdamsSystems.nl
Principal Consultant Adams Systems Consultancy
https://adamssystems.nl/

On Thu, Nov 06, 2025 at 03:00:02PM +0000, Alexander Pettitt via IBM TechXchange Community wrote:
> Dealing with the boot from SAN issue now.
>
> There are instructions and tools available from Dell-EMC.

The newer AIX MPIO Powerpath "shim" which is just ODM definitions
shouldn't have the same issues legacy Powerpath did.

The original problem was that legacy Powerpath would lie to rootvg
about what disks it had. In certain circumstances, that would go wrong
and leave the system unbootable.

Glad to see you Alex! Come hang out on ##aix on libera.chat IRC!

------------------------------------------------------------------
Russell Adams Russell.Adams@AdamsSystems.nl
Principal Consultant Adams Systems Consultancy
https://adamssystems.nl/


Original Message:
Sent: 11/6/2025 10:00:00 AM
From: Alexander Pettitt
Subject: RE: AIX Storage Migration

Dealing with the boot from SAN issue now.

There are instructions and tools available from Dell-EMC.

Look at this - Dell Technologies Host Connectivity Guide for IBM AIX

One complication we are facing is making sure we have valid snapshots through the migration process.

------------------------------
Alexander Pettitt
------------------------------

Hi Hashim

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