Mounting from zfs:zroot/ROOT/default failed with error 2: unknown file system after upgrade to 10.1-RELEASE

[Anton Eliasson]

Den 2014-11-19 18:17, Trond Endrestøl skrev:
> To break into the kernel debugger, enter this before booting the
> kernel:
>
> set debug.debugger_on_panic="1"
>
> Judging from the screenshots you've provided and from what you wrote
> in your reply, it seems vfs.root.mountfrom is overridden somehow.
> /boot/loader.conf would be a natural candidate.
>
> If the bootfs property is indeed set to zroot/ROOT/default, then it's
> very strange that the kernel would proclaim:
>
> Trying to mount root from zfs:zroot []...
>
> instead of:
>
> Trying to mount root from zfs:zroot/ROOT/default []...
>
> And it's even stranger that nothing appears on lszfs' radar when asked
> to list zroot/ROOT/default.
>
>> Selecting the old kernel in the boot menu and trying to boot normally fails
>> because init is not found:
>> https://cloud.solid.lth.se/public.php?service=files&t=81fd35bb6348ae7426553c2f59fb2a18
>>
>> Could this be a mismatch in kernel and kernel module versions? How would I fix
>> that?
> If you can boot from a recent snapshot image or live image, and import
> the zpool read-only, you could walk around and see if
> zroot/ROOT/default/boot/loader.conf contains anything strange.
>
> This zpool command would allow you to go spelunking inside /zroot:
>
>    zpool import -o readonly=on -f -R /zroot zroot
>
> You might need to mount readonly any dataset you wish to examine.
>
> If you see the need for changing any of the files, you must export the
> zpool and re-import it readwrite, i.e. leave out the -o readonly=on
> option.
>
> I admit I'm in unknown territory, even if I have managed multiple ZFS
> systems over the past years, so be careful.
>
Hi!
I had forgot to remove the vfs.root.mountfrom that I experimented with. 
This probably caused the failure to load init.

I got it to work by chrooting into the system from a live cd and rolling 
back the upgrade with `freebsd-update rollback`. Then it booted fine. 
Now freebsd-version shows 10.0-RELEASE-p12 and uname -r shows 
10.1-RELEASE. It looks a bit strange, but at least it works for now.

I may have mixed up the commands used to upgrade the system. Is the 
following the correct procedure for doing a major upgrade (with a stock 
kernel)?

freebsd-update -r 10.1-RELEASE upgrade
freebsd-update install
(reboot)
freebsd-update install
(rebuild ports)
(done)

Thanks for your help!

-- 
Best Regards,
Anton Eliasson