# zpool status
pool: lxc
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
lxc ONLINE 0 0 0
sda3 ONLINE 0 0 0
sdb4 ONLINE 0 0 0
errors: No known data errors
# zpool remove lxc sdb4
cannot remove sdb4: only inactive hot spares, cache, top-level, or log devices can be removed