ZFS pool unexpected name change

freebsd-questions:

I have VirtualBox on a Debian GNU/Linux machine:

2026-06-13 15:50:49 root@laalaa ~
# cat /etc/debian_version ; uname -a
11.11
Linux laalaa 5.10.0-43-amd64 #1 SMP Debian 5.10.251-5 (2026-05-15) 
x86_64 GNU/Linux

2026-06-13 15:55:27 root@laalaa ~
# dpkg-query -W -f='${Version}\n' virtualbox-7.0
7.0.26-168464~Debian~bullseye


VirtualBox is running a FreeBSD virtual machine:

2026-06-13 15:43:57 toor@vf2 ~
# freebsd-version -kru
14.4-RELEASE-p5
14.4-RELEASE-p5
14.4-RELEASE-p5

2026-06-13 15:46:15 toor@vf2 ~
# uname -a
FreeBSD vf2.tracy.holgerdanske.com 14.4-RELEASE-p5 FreeBSD 
14.4-RELEASE-p5 GENERIC amd64


Around FreeBSD 13.3 RELEASE, I created a virtual machine with two ZFS pools:

2024-10-20 14:29:58 toor@vf2 ~
# zpool create -f -m /altroot/vf2zpool1 vf2zpool1 gpt/vf2zpool1

2024-10-20 14:30:25 toor@vf2 ~
# zpool create -f -m /altroot/vf2zpool2 vf2zpool2 gpt/vf2zpool2


The pools worked correctly under FreeBSD 13.3-RELEASE, 13.4-RELEASE, and 
13.5-RELEASE.


Since upgrading to FreeBSD 14.4-RELEASE, I am unable to import the pools:

2026-06-13 15:46:23 toor@vf2 ~
# zpool import vf2zpool1
cannot import 'vf2zpool1': no such pool available

2026-06-13 16:01:50 toor@vf2 ~
# zpool import vf2zpool2
cannot import 'vf2zpool2': more than one matching pool
import by numeric ID instead


Looking for importable pools:

2026-06-13 16:02:00 toor@vf2 ~
# zpool import
    pool: vf2zpool2
      id: 16370591766194553060
   state: ONLINE
status: Some supported features are not enabled on the pool.
	(Note that they may be intentionally disabled if the
	'compatibility' property is set.)
  action: The pool can be imported using its name or numeric identifier, 
though
	some features will not be available without an explicit 'zpool upgrade'.
  config:

	vf2zpool2        ONLINE
	  gpt/vf2zpool2  ONLINE

    pool: vf2zpool2
      id: 15782797086784599572
   state: ONLINE
status: Some supported features are not enabled on the pool.
	(Note that they may be intentionally disabled if the
	'compatibility' property is set.)
  action: The pool can be imported using its name or numeric identifier, 
though
	some features will not be available without an explicit 'zpool upgrade'.
  config:

	vf2zpool2        ONLINE
	  gpt/vf2zpool1  ONLINE


Note that both pools now have the name "vf2zpool2".


I did not purposefully rename either pool.


Why do both pools now have the same name?


David