mogadm can not delete device?

[feihu]

root at xxx:~# mogadm device list
host214 [1]: alive
                   used(G) free(G) total(G)
  dev1: alive      5.826   66.137  71.963 

host222 [2]: down
                   used(G) free(G) total(G)
  dev2: down       0.000   0.000   0.000  
  dev8: down       0.000   0.000   0.000  

root at xxx:~# mogadm device delete host222 2
Help for 'device' command:
 (enter any command prefix, leaving off options, for further help)

  mogadm device add <hostname> <devid> [opts]        Add a device to a host.
  mogadm device list                                 List all devices, for each host.
  mogadm device mark <hostname> <devid> <status>     Mark a device as {alive,dead,down,readonly}

-- 
feihu <feihu.list at gmail.com>