The pool has been written to from another host, and was not cleanly exported
from the other system. Actively importing a pool on multiple systems will
corrupt the pool and leave it in an unrecoverable state. To determine which
system last accessed the pool, run the 'zpool import' command:
# zpool import
status: The pool was last accessed by another system.
action: The pool can be imported using its name or numeric identifier and
the '-f' flag.
# zpool import test
cannot import 'test': pool may be in use from other system, it was last
accessed by 'tank' (hostid: 0x1435718c) on Fri Mar 9 15:42:47 2007
use '-f' to import anyway
If you are certain that the pool is not being actively accessed by another
system, then you can use the '-f' option to 'zpool import' to forcibly
import the pool.