Re: cannot boot: ZFS: unsupported feature" com.klarasystems:vdev_zaps_v2

Marco Beishuizen <mbeis.bsd@xs4all.nl> writes:
> Quite unexpected (after a portupgrade) I suddenly can't boot anymore:
>  
> [...]
> BIOS drive C: is disk0
> ZFS: unsupported feature: com.klarasystems:vdev_zaps_v2

For this to happen you must have either a) upgraded your pool without
upgrading your boot loader, b) downgraded your boot loader, or c) booted
from the wrong medium (e.g. a CD or USB stick you forgot to remove
before rebooting).  Either way, portupgrade is not at fault.

If the problem is c), simply remove the media in question and reboot.
If the problem is either a) or b), you will need to boot from a CD or
USB stick with a FreeBSD 14 image on it (preferably 14.2, but 14.0 or
14.1 will do if that's what you have at hand) and upgrade your boot
loader as described in the gpart manual page or the ZFS chapter of the
FreeBSD handbook:

  https://docs.freebsd.org/en/books/handbook/book/#zfs-zpool-upgrade

DES
-- 
Dag-Erling Smørgrav - des@FreeBSD.org