I beleive in your previous postings u said you are using RAID5. That means wheather you have 1 extent or many , they will be spread out on a different drives . You will waste you time doing this export and import or in fact using any other thechniques. If you have 1 or 100 extents, WHO CARES! Even 1 extent is not contigious on a disks, besides how ofter (if ever) do you run compress utility on a disk ?

Regards