Comment 4 for bug 855871

In another installation, also with xfs, I left a 1-2 GB unpartitioned space at the beginning of the disk (plenty of space for the bios_grub partition), but grub again failed.

In another installation, I also tried the same patition layout as the original bug report (first 4GB swap, 1-2 GB unpartitioned, ~300 GB root partition) with ext4 rather than xfs and the bios_grub partition was created correctly and the system boots as expected.

I'm trying to narrow down whether the problem occurs due to deciding where the bios_grub partition gets placed, but it seems to only occur with xfs.