I've got a Mac Pro that has four SATA drives installed in it, and I've got two of those drives in a RAID-1 mirror, using just the onboard SATA ports and software RAID (no fancy external RAID card or anything). Those two drives are 1TB. I want to replace them with 4TB drives. If I replace one drive at a time, let them each rebuild, afterward will OS X allow me to re-size the partition to take up the full 4TB? Or, can you only do that by wiping out the disks? I know, "why don't you just back it up somewhere first and restore it" -- long story short, every means I have to do that is going to take forever to move that much data, and I'm only going to have a few hours in which to do this. Or, any better ideas for this?