The problem is that the raid drivers for linux for this are a devicemapper plugin (dmraid) which is alpha. It shows degraded mode because I didn't format before use. It doesn't support updating state in the metadata yet.
Oh, and it doesn't obscure the backing devices in any way, so I'm concerned about Linux LVM, at some point, getting confused, or maybe not even being able to find the RAID set and just using the raw devices.
So, I think I need to disable the BIOS metadata tagging of he devices and just use the linux MD drivers.