Re: Failure to boot after upgrade 14.3->14.4 with "ZFS: unsupported feature: com.klarasystems: vdev_zaps_v2"

On Thu, Apr 30, 2026 at 11:33:18AM +0200, Johan Helsingius wrote:
> I was upgrading from 14.3-r7 to 14.4, but after the
> freebsd-update -r 14.4-RELEASE upgrade,
> the reboot fails with
> "ZFS: unsupported feature: com.klarasystems: vdev_zaps_v2"
> without loading the kernel.
> 
> Any idea what that feature is, and how to recover?
> 
> 	Julf
> 
> 


Google suggests that your bootloader doesn't support the features of the root partition. Did you perhaps do a "zfs upgrade"? You need to boot from external medium and update the bootloader.
 Depending on whether you use UEFI or Bios the steps differ.
 
Best regards,
Daniel