# zpool status mont1
  pool: mont1
 state: ONLINE
status: One or more devices has experienced an unrecoverable error.  An
        attempt was made to correct the error.  Applications are unaffected.
action: Determine if the device needs to be replaced, and clear the errors
        using 'zpool clear' or replace the device with 'zpool replace'.
   see: http://www.sun.com/msg/ZFS-8000-9P
 scan: resilvered 2.53G in 5h5m with 0 errors on Wed Feb 29 14:25:52 2012
config:

        NAME        STATE     READ WRITE CKSUM
        mont1       ONLINE       0     0     0
          mirror-0  ONLINE       0     0     0
            ad8     ONLINE       0     0     0
            ad10    ONLINE       0     0     0
          ad4       ONLINE       0     0    66