Re: GPT questions - gpt reliability, wedge naming, and filesystem scaling.

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Sun, 22 Jun 2014 07:23:26 +0100
    From:        Gerard Lally <lists+netbsd.users%netmail.ie@localhost>
    Message-ID:  <20140622072322.94D6.280FC639%netmail.ie@localhost>

  | Luckily enough I came upon the instructions below, and booting worked
  | for me without issue:
  | 
  | http://wiki.netbsd.org/users/jakllsch/gptboot/

Yes, that's what I used as a guide too.   But I did it on a drive that
was completely new, never partitioned by anything before, and that didn't
work (where it did work fine on another drive that I initially set up the
old way with MBR partitioning).   I suspect that the GPT setup stuff is
failing to set one (or more) of the MBR flags - or something like that - and
the BIOS decides there's nothing bootable there (NetBSD doesn't yet support
the newer boot partition method of booting.)   But when it converts an existing
MBR to a PMBR, it just changes the type and begin/end of partition 1, but
leaves the rest of it alone, so we get the benefits of the initial fdisk setup.

That's what I meant when I said you had kind of fluked on it - you did the
MBR partitioning (for an entirely unrelated reason) and that allowed the
GPT boot method to work.

If I knew enough about MBRs and PC booting I'd see if I could produce a patch,
but, alas, I don't ...

  | Aside: are you the same Robert
  | Elz who was involved from the outset in FFS?

I have been involved with BSD since long before FFS, so in a sense, yes,
however, also no, as I really had nothing to do with FFS, that's all
Kirk McKusick's work.

kre