in a two disk setup
i created per disk 3 partitions
bios_grub 1mb linux raid 512mb md0 (/boot - ext3) linux raid rest md1 (physical volume for lvm)
the answer on https://unix.stackexchange.com/a/218384 states that it is not possible to create a mirror raid for bios grub
You will need hardware RAID if you want the BIOS boot partition to be mirrored.
but on https://askubuntu.com/a/57010 it looks like it is possible but there is no info how it works
You will need hardware RAID if you want the BIOS boot partition to be mirrored. You can, however, install GRUB to multiple drives; just run grub-install in the target OS on each drive that has a BIOS boot partition (give it the entire drive, like /dev/sda, as an argument; grub-install will figure out the location of the BIOS boot partition from the GPT).
so is it possible to create a software raid for the bios_grub partition? if yes how? currently i use fai setup-storage to create the partitions.