missing cache vdev

gistfile1.txt

bash-3.2# zpool status
  pool: test2
 state: ONLINE
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://zfsonlinux.org/msg/ZFS-8000-2Q
  scan: resilvered 736K in 0h0m with 0 errors on Sat Jun 14 17:23:51 2014
config: 

        NAME        STATE     READ WRITE CKSUM
        test2       ONLINE       0     0     0
          disk1     ONLINE       0     0     0
        cache
          disk3     UNAVAIL      0     0     0  cannot open

errors: No known data errors

bash-3.2# zpool online test2 disk3
warning: device 'disk3' onlined, but remains in faulted state
use 'zpool replace' to replace devices that are no longer present

bash-3.2# zpool offline test2 disk3

bash-3.2# zpool status
  pool: test2
 state: ONLINE
status: One or more devices has been taken offline by the administrator.
        Sufficient replicas exist for the pool to continue functioning in a
        degraded state.
action: Online the device using 'zpool online' or replace the device with
        'zpool replace'.
  scan: resilvered 736K in 0h0m with 0 errors on Sat Jun 14 17:23:51 2014
config:

        NAME        STATE     READ WRITE CKSUM
        test2       ONLINE       0     0     0
          disk1     ONLINE       0     0     0
        cache
          disk3     OFFLINE      0     0     0

errors: No known data errors

bash-3.2# zpool replace test2 disk3 disk2
invalid vdev specification
use '-f' to override the following errors:
/dev/disk2 is part of unknown pool 'test2'

bash-3.2# zpool replace -f test2 disk3 disk2
cannot replace disk3 with disk2: device is in use as a cache

bash-3.2# zpool online test2 disk3
warning: device 'disk3' onlined, but remains in faulted state
use 'zpool replace' to replace devices that are no longer present

bash-3.2# zpool status
  pool: test2
 state: ONLINE
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://zfsonlinux.org/msg/ZFS-8000-2Q
  scan: resilvered 736K in 0h0m with 0 errors on Sat Jun 14 17:23:51 2014
config: 

        NAME        STATE     READ WRITE CKSUM
        test2       ONLINE       0     0     0
          disk1     ONLINE       0     0     0
        cache
          disk3     UNAVAIL      0     0     0  cannot open

errors: No known data errors

bash-3.2# zpool replace test2 disk3 disk2
invalid vdev specification
use '-f' to override the following errors:
/dev/disk2 is part of unknown pool 'test2'

bash-3.2# zpool replace -f test2 disk3 disk2
cannot replace disk3 with disk2: device is in use as a cache

bash-3.2# zpool labelclear /dev/disk2
labelclear operation failed.
        Vdev /dev/disk2 is a member (L2CACHE), of pool "test2".
        To remove label information from this device, export or destroy
        the pool, or remove /dev/disk2 from the configuration of this pool
        and retry the labelclear operation.

bash-3.2# zpool labelclear -f /dev/disk2
labelclear operation failed.
        Vdev /dev/disk2 is a member (L2CACHE), of pool "test2".
        To remove label information from this device, export or destroy
        the pool, or remove /dev/disk2 from the configuration of this pool
        and retry the labelclear operation.
        
bash-3.2# zpool offline test2 disk3

bash-3.2# zpool labelclear /dev/disk2
labelclear operation failed.
        Vdev /dev/disk2 is a member (L2CACHE), of pool "test2".
        To remove label information from this device, export or destroy
        the pool, or remove /dev/disk2 from the configuration of this pool
        and retry the labelclear operation.
 
bash-3.2# zpool labelclear -f /dev/disk2
labelclear operation failed.
        Vdev /dev/disk2 is a member (L2CACHE), of pool "test2".
        To remove label information from this device, export or destroy
        the pool, or remove /dev/disk2 from the configuration of this pool
        and retry the labelclear operation.

bash-3.2# zdb -ssU /etc/zfs/zpool.cache.tmp test2
                            capacity   operations   bandwidth  ---- errors ----
description                used avail  read write  read write  read write cksum
test2                     2.23M  121M   181     0 1.57M     0     0     0     0
  /dev/disk1              2.23M  121M   181     0 1.57M     0     0     0     0
  /dev/disk3                              0     0     0     0     0     0     0
  
bash-3.2# zpool remove test2 disk3

bash-3.2# zpool add test2 cache disk3
cannot open 'disk3': no such device in /dev
must be a full path or shorthand device name

bash-3.2# zpool add test2 cache disk2

bash-3.2# zpool status
  pool: test2
 state: ONLINE
  scan: resilvered 736K in 0h0m with 0 errors on Sat Jun 14 17:23:51 2014
config:

        NAME        STATE     READ WRITE CKSUM
        test2       ONLINE       0     0     0
          disk1     ONLINE       0     0     0
        cache
          disk2     ONLINE       0     0     0

errors: No known data errors