Re: Problem updating bootcode on ZFS on root system with MBR

On Sun, Jan 26, 2014 at 3:46 AM, Scot Hetzel <swhetzel_at_gmail.com> wrote:

> On Tue, Jan 21, 2014 at 3:11 PM, Thomas Hoffmann <trh411_at_gmail.com> wrote:
> > On Tue, Jan 21, 2014 at 10:47 AM, Andriy Gapon <avg_at_freebsd.org> wrote:
> >
> >> on 21/01/2014 13:18 Andrey V. Elsukov said the following:
> >> > On 21.01.2014 14:45, Andriy Gapon wrote:
> >> >>>> What do I need to do to get the boot2 code written to /dev/ada0s1a?
> >> >>>
>
> >> >>>> # dd if=/boot/zfsboot of=/dev/ada0s1a skip=1 seek=1024
> >> >>>> dd: /dev/ada0s1a: Operation not permitted
>
> > Thanks for the responses. My apologies for going silent, but I had to
> step
> > away from the problem for a bit. I was able to resolve my problem by
> doing
> > the following:
> >
> > After upgrading my zpools and after my aborted attempt to update the
> > bootcode as reported above, I copied /boot/zfsboot (or more precisely
> > /bootpool/boot/zfsboot) to a USB thumb drive. I attempted to reboot my
> > system, which failed due to unsupported zfs features. This was expected,
> > but I thought, hey, I might get lucky. I then booted into a Live CD,
> > mounted my USB thumb drive on /tmp/usb and executed:
> >
> > sysctl kern.geom.debugflags=0x10
> > dd if=/tmp/usb/zfsboot of=/dev/ada0s1 count=1
> > dd if=/tmp/usb/zfsboot of=/dev/ada0s1d skip=1 seek=1024
> >
> > Then I rebooted and all is well. All zpools support all features. While
> > this procedure was not tedious, it would still be nice if, as Andriy
> > stated, FreeBSD contained a native way do this zfs bootcode update for
> MBR
> > schemes that is as simple as for the GPT schemes.
> >
> In your original message, you were trying to write the boot code to
> ada0s1a, but you made it work by using ada0s1d.
>
> Do you have an ada0s1a?  If you do, is it your ZFS partition or is it
> ada0s1d?
>

I can see why you are confused. In between the original problem and the
solution I did a fresh install of FreeBSD-10.0-REL, which creates a
bootpool on ada0s1a, swap on ada0s1b and the zfs partition on ada0s1d. So
that is why the discrepancy between the original problem and solution. The
original system had the zfs partition on ada0s1a and swap on ada0s1b.

In retrospect I should have been more clear on this in my postings.

BTW, I got the [definitive] update process for zfs bootcode on MBR
partitioned systems from you a while back. So thanks for that. I actually
understand what I'm doing now when I update the zfs bootcode.

-Tom

>
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