Moving a bootable ZFS USB between systems

[Peter Pauly]

I installed FreeBSD 11 with an encrypted GELI root and ZFS (zroot) on a USB
stick. My intention was to boot off of it on several systems. It works fine
on the original system but not on a second system.

I get this message:
Mounting from zfs:zroot/ROOT/default failed with error 5.

The USB stick is da0.

The geli part looks like it works, but the zfs mount fails.

Should I be able to move the stick between systems or do I need to do a
zpool export zroot first? If so, where is the best place to put this
(rc.shutdown?)

I asked this question on freebsd-questions and didn't get a response.

Thanks for your help.