11.2 cannot boot with root on ZFS

Matthias Fechner idefix at fechner.net
Sun Aug 5 10:02:10 UTC 2018

Hi Kyle,

sry that it took longer, but I had a harddisk failure and it took some
time to resilver the pool to a new disc.

Am 16.07.2018 um 19:45 schrieb Kyle Evans:
> To be clear- the kernel can't find the zfs pool, or one of the earlier
> stages? Giving the pool manually meaning at a mountroot prompt, or
> somewhere else?

I'm not sure what the problem is.
If I update the kernel from 11.1 to 11.2 with freebsd-update and reboot,
it could be a kernel panic with an immediate reboot.
It is that fast, that it is impossible to see anything on the screen, so
I cannot give you a clear error message for this.

If I try then to boot the old kernel in the bootloader with:
load /boot/kernel.working/kernel

it is not able to mount the zroot pool.

To fix this, I need to boot mfsbsd from an USB stick and do:
zpool import -o altroot=/mnt zroot
cd /mnt
tar xjvf boot_111_working.tar.bz2
cd /
zpool export zroot

> This is for specifically for aarch64, but you've not specifically
> mentioned it- you're on aarch64, right?
you are right, I'm on a normal amd64 platform.

> I think we'll need a little more information about where and
> specifically how it's failing for you to determine that. Others have
> reported successful upgrades from 11.1 to 11.2 with root-on-ZFS
> setups.

is it maybe the way the disc are partitioned?

I have an empty EFI partition on the harddisk (to have later space for EFI):
gpart show ada0
=>        40  5860533088  ada0  GPT  (2.7T)
          40      262144     1  efi  (128M)
      262184         512     2  freebsd-boot  (256K)
      262696  5860270424     3  freebsd-zfs  (2.7T)
  5860533120           8        - free -  (4.0K)

The bootloader is correctly installed using:

gpart bootcode -b /boot/pmbr -p /boot/gptzfsboot -i 2 ada0



"Programming today is a race between software engineers striving to
build bigger and better idiot-proof programs, and the universe trying to
produce bigger and better idiots. So far, the universe is winning." --
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