Comment 14 for bug 1487365

Got it; the other distro doesn't put the PReP partition on the RAID/md device itself -- it uses the (non-RAID) partition on /one/ of the underlying block devices.

# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 931.5G 0 disk
├─sda1 8:1 0 7M 0 part
├─sda2 8:2 0 9.3G 0 part /boot
├─sda3 8:3 0 921.3G 0 part
│ └─md127 9:127 0 921.1G 0 raid1 /
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 952M 0 part [SWAP]
sdb 8:16 0 931.5G 0 disk
└─sdb1 8:17 0 921.3G 0 part
  └─md127 9:127 0 921.1G 0 raid1 /