The nimadm migration worked fantastically. Now to destroy old_rootvg,
mirror hdisk0 back to hdisk1, then change bootlist back to hdisk0.
However, the only way I can find to destroy the old_rootvg is
through smitty, but smitty (the commands it executes) wants old_rootvg
to be vary'd on (varyonvg old_rootvg), but this command can't
find the device(?) and wants me to run redefinevg before it will
vary on old_rootvg. I'm reluctant to go forward.

The question is what to do now? I want to destroy old_rootvg
(this contains the old 4.3.3 os), extendvg rootvg hdisk0,
mirrorvg -c 2 rootvg hdisk0, bootlist -m normal hdisk0 hdisk1,
bootlist -ad /dev/hdisk0.

Suggestions?

Mike