During my latest experiments with LVM and LUKS in diverse combinations, I’ve encountered a very peculiar behaviour: after I’ve setup my MBR partition table and rebooted, the PC hung itself at POST, saying Auto-Detecting AHCI PORT 0, to which my SATA HDD was attached. The only way to pass POST turned out to be either detaching the newly partitioned HDD (port 0) or… switching the motherboard SATA controller to the IDE (compatibility) mode instead of the AHCI mode in the BIOS. Neither of which is satisfactory. How come?

Well, this seems to be a bug in the way the controller (-firmware?) tries to detect the partitioning scheme of the HDD (which is needed for booting) and is most often easily resolved by resizing the first partition on the hard drive by a few MBs. This bug seems to be relatively widespread, but its actual causes remain a mystery to me. If anyone can shed some light on the machinery behind this, please comment.