Les Mikesell wrote:
If you have both, I'm not sure which wins. If you find documentation on the detection order or how to move devices, please post a link.
The kernel wins. As soon as raid* device drivers are loaded (for example, from initrd image, waaaay before even root file is mounted), they'll do the automagic stuff. The system will spit warnings later if information in mdadm.conf is contradicting.