Quick fix…

Rebuild the ramdisk. If you are using a rescue disk and are compiling for a different kernel version replace $(uname -r) with your kernel version:

dracut –mdadmconf –fstab –add=”mdraid” –filesystems “xfs ext4 ext3 tempts devotes syses proc” –add-drivers=”raid1″ –force /boot/initramfs-$(uname -r) $(uname -r)

Add the following to /etc/default/grub inside the quotes for the GRUB_CMD_LINUX argument:

rd.auto rd.auto=1

Also append this line to the same file:

GRUB_RELOAD_MODULES=”mdraid1x”

Rebuild the grub config:

grub2-mkconfig -o /boot/grub2/grub.cfg

Reinstall grub on sda or whatever drive you’re booting to:

grub2-install /dev/sda

Reboot.