If you install Fedora 12 with /boot on a RAID array - either as its own partition or as part of a root partition that is on a RAID array - and also install the bootloader to that partition rather than to the system MBR, the partition will not be marked as bootable, as it should be. This renders the installed Fedora unbootable. To work around this issue, you must manually mark the appropriate partition as bootable with a tool such as fdisk.

This bug should be fixed for Fedora 13 releases (anaconda-13.8-1 or greater).

Okay... very similar issue to the Debian bug.

How I fixed it? I'm not an expert, but I installed grub on the MBR of /dev/sda during installation of Fedora (with RAID1 array already configured), rebooted, and then manually installed grub on /dev/sda and /dev/sdb, rebooted and tested.

Works like a champ.