partitioning dilemma

[Aragon Gouveia]

On 05/05/11 22:02, Aragon Gouveia wrote:
> Are you able to boot such partitions? Over here my system is just
> entering a boot loop. BIOS has UEFI disabled, and I know for certain the
> pmbr code is being executed, but not sure if it gets as far as chaining
> to gptboot code.
>
> Here's what I have:
>
> # gpart show ada2
> => 34 468862061 ada2 GPT (223G)
> 34 524254 1 efi (256M)
> 524288 128 2 freebsd-boot (64k)
> 524416 524160 - free - (256M)
> 1048576 67108864 3 freebsd [bootme] (32G)
> 68157440 67108864 4 freebsd (32G)
> 135266304 67108864 5 freebsd-swap (32G)
> 202375168 33554432 6 freebsd-zfs (16G)
> 235929600 201326592 7 freebsd-zfs (96G)
> 437256192 31605903 - free - (15G)
>
> # gpart show ada2s3
> => 0 67108864 ada2s3 BSD (32G)
> 0 2048 - free - (1.0M)
> 2048 2097152 1 freebsd-ufs (1.0G)
> 2099200 8388608 2 freebsd-ufs (4.0G)
> 10487808 33554432 4 freebsd-ufs (16G)
> 44042240 23066624 - free - (11G)
>
>
> GPT and BSD schemes have /boot/pmbr and /boot/boot bootcode
> respectively. GPT partcode applied to partition 2 from /boot/gptboot.

So I've been doing some more experimenting and it looks like my boot 
loop was caused by the return in sys/boot/i386/gptboot/gptboot.c:159.  I 
replaced the return line with an infinite loop, which allowed me to read 
gptboot's error message, "no UFS partition was found".  Upon further 
inspection, it looks like gptboot won't boot off a BSD labeled GPT 
partition.

As a workaround I've done:

# gpart show ada2
=>       34  468862061  ada2  GPT  (223G)
          34        128     1  freebsd-boot  (64k)
         162     524126        - free -  (255M)
      524288     524288     2  freebsd-ufs  [bootme]  (256M)
     1048576   67108864     3  freebsd  (32G)
    68157440   67108864     4  freebsd  (32G)
   135266304   67108864     5  freebsd-swap  (32G)
   202375168   33554432     6  freebsd-zfs  (16G)
   235929600  201326592     7  freebsd-zfs  (96G)
   437256192   31605903        - free -  (15G)

I newfs'd ada2p2 and copied a /boot directory there.  I was hoping I'd 
be able to instruct loader to use ada2s3a as its rootdev, but alas, not 
even loader will read a BSD labeled GPT partition!  For now I've also 
created /etc/fstab on ada2p2 which allows the kernel to boot from 
ada2p2, but mount / from the gmirror volume on ada2s3 and ada3s3.  This 
seems like such an ugly hack that I'm reconsidering EBR if I can figure 
out how to calculate the partition offsets I want.

Any other suggestions appreciated!


Thanks,
Aragon