pjjw@push:~$ zpool status data
  pool: data
 state: DEGRADED
status: One or more devices could not be opened.  Sufficient replicas exist for
        the pool to continue functioning in a degraded state.
action: Attach the missing device and online it using 'zpool online'.
   see: http://www.sun.com/msg/ZFS-8000-2Q
 scrub: resilver completed with 0 errors on Sat Oct 13 20:42:18 2007
config:

        NAME        STATE     READ WRITE CKSUM
        data        DEGRADED     0     0     0
          raidz1    DEGRADED     0     0     0
            c4d0    ONLINE       0     0     0
            c5d0    ONLINE       0     0     0
            c4d1    ONLINE       0     0     0
            c5d1    ONLINE       0     0     0
            c2t4d0  UNAVAIL      0     0     0  cannot open

errors: No known data errors
pjjw@push:~$ sudo format
Searching for disks...done


AVAILABLE DISK SELECTIONS:
       0. c0d0 <DEFAULT cyl 24318 alt 2 hd 255 sec 63>
          /pci@0,0/pci-ide@8/ide@0/cmdk@0,0
       1. c0d1 <ST320082-         4LJ0QEG-0001-186.31GB>
          /pci@0,0/pci-ide@8/ide@0/cmdk@1,0
       2. c1d0 <ST320082-         3LJ3CD0-0001-186.31GB>
          /pci@0,0/pci-ide@8/ide@1/cmdk@0,0
       3. c2d0 <ST320082-         5LJ03Y4-0001-186.31GB>
          /pci@0,0/pci-ide@9/ide@0/cmdk@0,0
       4. c3d0 <ST350063-         9QG3TVD-0001-465.76GB>
          /pci@0,0/pci-ide@a/ide@0/cmdk@0,0
       5. c4d0 <ST350063-         6QG0AEC-0001-465.76GB>
          /pci@0,0/pci10de,ed@e/pci-ide@a/ide@0/cmdk@0,0
       6. c4d1 <ST350063-         6QG0949-0001-465.76GB>
          /pci@0,0/pci10de,ed@e/pci-ide@a/ide@0/cmdk@1,0
       7. c5d0 <ST350063-         6QG0B8A-0001-465.76GB>
          /pci@0,0/pci10de,ed@e/pci-ide@a/ide@1/cmdk@0,0
       8. c5d1 <ST350063-         6QG0A9N-0001-465.76GB>
          /pci@0,0/pci10de,ed@e/pci-ide@a/ide@1/cmdk@1,0
Specify disk (enter its number): ^C
pjjw@push:~$ sudo zpool replace data c2t4d0 c3d0
cannot replace c2t4d0 with c3d0: device is too small