GPT boot from 2nd. disk fails
Daniel Braniss
danny at cs.huji.ac.il
Thu Aug 16 07:06:49 UTC 2012
> On Wednesday, August 15, 2012 4:46:28 am Garrett Cooper wrote:
> > On Wed, Aug 15, 2012 at 1:27 AM, Daniel Braniss <danny at cs.huji.ac.il> wrote:
> > > hi,
> > > this host has to disks:
> > > sa0> gpart show
> > > => 34 976773101 ada0 GPT (465G)
> > > 34 128 1 freebsd-boot (64k)
> > > 162 4194304 2 freebsd-ufs (2.0G)
> > > 4194466 33554432 3 freebsd-swap (16G)
> > > 37748898 939024237 4 freebsd-zfs (447G)
> > >
> > > => 34 976773101 ada1 GPT (465G)
> > > 34 128 1 freebsd-boot (64k)
> > > 162 4194304 2 freebsd-ufs [bootme] (2.0G)
> > > 4194466 8388608 3 freebsd-swap (4.0G)
> > > 12583074 964190061 4 freebsd-zfs (459G)
> > >
> > > but no amount of magic will cause boot from the second disk, it will
> always
> > > boot from the first disk.
> > >
> > > any insights?
> >
> > Use boot0cfg -s 5 (untested with GPT disks)?
>
> Will not work with GPT disks. They use /boot/pmbr to boot, not /boot/boot0.
>
> If you can get your BIOS to explicitly boot ada1 from the start via a BIOS
> setting, that should work. Another option would be to break into gptboot's
> prompt (similar to breaking into boot2) aud typing in 'ad1p2:/boot/loader' or
> some such. If that works you should even be able to write that to
> /boot.config on ada0p2's filesystem.
sorry, as usual my questions are a bit terse :-),
I want to switch between roots either at boot time (this is very tricky now,
since breaking into boot2 needs very fast fingers) or before reboot.
btw, it's 1:ad(0p2)/boot/loader
also, since the disks are hot swap, i can switch between them, but I realy
want to do it via software!
the bootme trick did work, on a different host/setup and sometime ago.
before GPT, when we had MBR, I could switch between slices/partitions either
via the menu or via boot0cfg, so maybe I should go back to mbr.
Cheers,
danny
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