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

Johan Helsingius <[email protected]> Thu, 30 Apr 2026 11:33:18 +0200

Newsgroups	gmane.os.freebsd.questions
Message-ID	<[email protected]>

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