This limit should rarely become a problem. It was a barrier in the early days, but you can use the –t option to increase the maximum PVs per VG with a chvg –t. You can do this any time.

From: toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] On Behalf Of Alexander Griesser
Sent: Friday, May 18, 2012 1:33 PM
To: Milazzo Giacomo; toasters@teaparty.net
Subject: AW: LUN migration and consolidation

Hello Milazzo,

this will work (did that quite a few times in the past), but AIX is going to be nasty here, because when you create volume groups, you need to define parameters for maximum logical volumes in a vg and that limits the size of the logical volumes, so you might end up migrating the data two times.

We had the same situation where our previous storage guy thought that slicing a 500gb Lun into a gazillion pieces increases performance and so we had about 50 10GB sized LUNs in one volume group for just one filesystem. To migrate the data without disruption we had to go for some intermediate steps like 10*50 first, then adapt the volume group parameters, then migrate to 2*250 and finally to 1*500 – YMMV here, depending on the configuration of your volume group.

Bye,

Alexander Griesser

System-Administrator

ANEXIA Internetdienstleistungs GmbH

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Von: toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] Im Auftrag von Milazzo Giacomo
Gesendet: Freitag, 18. Mai 2012 14:05
An: toasters@teaparty.net
Betreff: LUN migration and consolidation

Hi all,

I have the following situation.

Source file system: an AIX volume created on hundreds of very small LUNs (HDS storage array, something like 15 GB each!)

Destination file system: a “mirrored” one to online migrate using LVM with no disruption on services but at the same time consolidating on a single LUN on NetApp (as you know the geometry is completely different!)

In the past I did it but on a 1:1 relationship between source and destination LUNs.

Not there’s somebody stating that on AIX this is not possible… ?!? But this is possibile on any distribution of Linux too!!!

My idea in other words is to map the new space to the same AIX host that will use to create a sort of R1 between file systems (Veritas Volume Manager also doed this i.e)

regards