Wheres the FreeBSD PBR ? (was Re: Manually partitioning using gpart / wh)

Lucas B. Cohen lbc at bnrlabs.com
Sun Nov 25 14:11:06 UTC 2012


On 2012.11.25 14:35, Ralf Mardorf wrote:
> I don't need it, but I could add it for what ever worst case emergency
> scenario and GRUB in the MBR anyway will work?
I don't see how it could ever come in handy, and I'm not sure it
wouldn't do any hamr either. The /boot/gptboot code to be written weighs
15kB, that could be big enough to mess up the filesystem on the
partition. That /boot/gptboot code is designed to work on a
special-purpose small GPT partition that doesn't hold a filesystem. So I
would refrain from doing it.

It would be useful for emergency purposes to write MBR-partition
scheme-compatible bootcode to that partition instead, but I've yet to
find out how to do it. gpart(8) seems to have the ability to do it, but
it's manual page doesn't mention what file to pass to its -p option to
do that. Maybe it's one of those /boot/boot1 or /boot/boot2 files I'm
seeing on my system. Maybe someone can enlighten me on that.


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