disk serial number in HW raid volume in T5220

Hi
I have a question, if do I have any reasonable way to identify disk drive serial number without shutdown the system ?

The condition is
- Disks are the member of mirror volume configured using on board raid controller.

I try iostat -En, raidctl command below but neither do show disk's serial number. If the system is T3, or T4 I know
either sas2ircu or MegaCLI can provide the info.

TIA
Tomonori-

-----------------------------------------------------------------------------------
t5220# raidctl -l -g 0.4.0 1
Disk    Vendor  Product         Firmware        Capacity        Status  HSP
----------------------------------------------------------------------------
0.4.0   SEAGATE ST973451SSUN72G 0302            68.3G           GOOD    N/A
t5220#
t5220# iostat -En
c0t0d0           Soft Errors: 0 Hard Errors: 0 Transport Errors: 0