if you're the person who manages both VIO and DS do carve all the disks
on DS -- it will save you time and lot of problems... and if you
decided to go with dual VIO and MPIO you would not need to reconfigure
everything from scratch, same true if you decided to not to use VIO
anymore in the future... Virtualization is good to a point... and the
point is you should be able to go both direction -- using
virtualization and not, but data should be preserved at all time. Also
read differences on lv backed and disk backed virtual scsi disks in
VIOS documentation, I think you'll find it appealing.