Jeff,

You could add the new physical disk to the same volume group on the AIX system 
and then use the migratepv command to shift the logical volume containing the 
adsm database (assuming it is on it own LV). Use the command:

migratepv -l logical_volume_name from_disk to_disk.

I have shifted many lv's this way without any problem and the good thing is it 
can be done 'on the fly'.

Of course if the LV contains other files and directories they will also be 
moved so the above command may not be what you want, say if you want to 
seperate the adsm db out from other files etc.

The migratepv command is good only within the same volume group.

Best Regards,

Peter Zutenis   
Principal Systems Programmer
Philip Morris Information Services Ltd
Moorabbin, Australia.