I had some issues with the pools created on FreeBSD (7.2-8) with ZFS (version 6 to 13) when I tried migrating those to (Open)Solaris/Nexenta.
Something like this:
# zpool import -f
pool: tank
id: 2794438138141825953
state: UNAVAIL
status: One or more devices contains corrupted data.
action: The pool cannot be imported due to damaged devices or data.
see: http://www.sun.com/msg/ZFS-8000-5E
config:
tank UNAVAIL insufficient replicas
raidz1 UNAVAIL corrupted data
c0t1d0p0 ONLINE
c0t2d0s8 UNAVAIL corrupted data
c0t3d0s2 ONLINE
# zpool import -f tank
cannot import 'tank': no such pool or dataset

The point is that c0t2d0s8 is actually a slice device along with c0t3d0s2 and the only real device is actually c0t1d0p0. So (re)moving, the slice devices from /dev/rdsk/ should leave anything but real devices (which should actually represent the real raidz arrays).

Something like this should help:

mkdir /tmp/bad_devs
cd /tmp/bad_devs
for i in /dev/rdsk/c7t[0123456789]d0s*; do mv $i ./; done
zpool import -f tank
zpool upgrade -V 14 tank


Still, I can’t explain how it came up like this in FreeBSD. :(