Re: [CentOS] *very* ugly mdadm issue [Solved, badly]

Ok, folks,

Here's the answer: making a software RAID on a bare drive with no GPT works fine. If it has a GPT, and no partition, it fails on reboot, even with an /etc/mdadm.conf.

I've proved this: first, I created the array on the bare drive, rebooted, and /dev/md0 was there; then, I used parted to create a gpt, then the array, reboot, no md0, even with mdadm --assemble, even with /etc/mdadm.conf. finally, I got rid of the disk label (parted to make an msdos label, the zeroing out the beginning of the disk), and again made the RAID on the bare drives, reboot, and md0 is there.

So that's what killed me. Admins, take heed....

mark