[linux-lvm] changing pe size

[Joe Pruett]

> i have looked around the net and not found much info about this...

so i spent time experimenting...

> i have a centos 5 system with a 32m pe size vg and have attached some
> storage with an lvm1 4m pe size vg.  i converted the old vg to lvm2
> without problem, but i would like to merge the volumes and pvmove data
> onto the newer 32m pe pvs.  but you can't merge things with different pe
> size, so i've been trying to get the 4m pe vg changed to 32m pe.  after
> much monkeying around i was able to get all the pvs and lvs to have le
> counts that were the right size to be convertible to 32m pe.  but it
> looks like each segment must be sized appropriately and i can't find a
> way to merge segments together so that things are sized correctly.

it turns out that pvmove will coalesce adjecent segments.  so i was able 
to use a series of pvmoves to get all my segments to be contiguous and a 
mulitple of the new pe size i wanted.

once i did that, then vgchange -s worked just fine.