ORACLE - ASM CHECK ALL DISK GROUP

How to verify all disk for a group ?

alter diskgroup MWDATA1 check all norepair;

SQL> alter diskgroup MWDATA1 check all norepair
NOTE: starting check of diskgroup MWDATA1
Thu Mar 07 12:11:42 2013
GMON checking disk 1 for group 1 at 25 for pid 20, osid 10202
Thu Mar 07 12:11:54 2013
GMON checking disk 2 for group 1 at 26 for pid 20, osid 10202
Thu Mar 07 12:11:58 2013
SUCCESS: check of diskgroup MWDATA1 found no errors
SUCCESS: alter diskgroup MWDATA1 check all norepair