How to recover data from dead hard drive.

[tech-lists]

On Thu, Oct 19, 2017 at 10:25:31AM +0100, Frank Leonhardt (m) wrote:

>If you're lucky this is caused by bhyve. However, by this stage, if 
>you're booting from a once-working boot drive then the ZFS stuff should 
>have been brought in by the loader, allowing it to mount the FS  
>and load the OS.
>
>Have you tried specifying a different device? (Its safe to guess).
>
>I'd probably mount the image using mdconfig on a ZFS enabled machine 
>(type zpool to check it's been compiled with the right modules) and 
>see if it can auto-mount. Easier than sorting out boot problems, 
>especially if the boot partition has been clobbered.

I'll try again hopefully later today and get back with detailed results.
I've tried most of what you've suggested, but not exactly.

>ZFS is surprisingly good at reassembling stuff from odd locations using 
>GUID  metadata. Only worry I have is that its part of a striped vdev, 
>which will allow you to boot that far using code duplicated on each 
>drive, but then no further.

ZFS was installed single-disk root-on-zfs with no other options, so if
there is/are vdevs present, it would be something defaulted to. I don't
think there's any vdev.

Thanks again for taking the time to answer. I'll get back later with 
better data.
-- 
J.