I have 5 drives in a RAID 5 array. I am swapping them all out for new drives. Rather than waiting for the long rebuild time incurred by adding each drive, I'm curious as to whether I can just clone each drive using dd. I don't know exactly how mdadm knows which drives belong in the array and whether simply cloning a drive will allow it to exist in the array without a rebuild.

I suspect cloning each drive will be faster than rebuilding each drive. Faster means less uptime for the drives being replaced, which is ideal.