ZFS Root Mount Failure

[Erik Gustafson]

On Tue, Oct 28, 2014 at 10:40 PM, Stephen R Guglielmo <srguglielmo at gmail.com
> wrote:

> Hey list,
>
> I have a machine running ZFS on root. It stopped responding this morning,
> and upon a reboot, it was unable to mount root from zfs:zroot. It gave the
> explanation of "error 5."
>
> I played with the mount prompt briefly, but didn't get anywhere. Any tips
> for diagnosing and fixing the problem?
>

I had a similar issue recently. Error 5 on mount root. This was in
virtaulbox after some sort of unexpected shutdown.
To resolve i first made a snapshot in virtualbox
booted from freebsd-disc1.iso (install dvd)
zpool import
reboot (and boot from zroot)
zpool scrub

zpool scrub said that i was going to loose some recently written data
(generated by nightly poudrire build)
I don't remember all, probably I needed some parameter to zpool import but
all error messages were helpful it was quite easy to get it working again.

Good luck and don't forget the backup/snapshot