How to remove a disk or diskgroup

Question

Without breaking up your db, is there a way to remove a disk or disk group ?
thanks,
Chau

Answer 1

I dropped a diskgroup but the disks are still listed in v$asm_disk; the strange thing is that they are associated with disk group 0...see query result:
SQL> select name,path,group_number from v$asm_disk;
NAME
PATH
GROUP_NUMBER
/opt/NetApp/smo/mnt/-u03-20121224173628148_0/data1
     0
/opt/NetApp/smo/mnt/-u03-20121224173628148_0/data2
     0
NAME
PATH
GROUP_NUMBER
DB1_REDO_0000
/u05/redo1
     5
DB1_REDO_0001
/u05/redo2
NAME
PATH
GROUP_NUMBER
     5
DATA_0000
/u02/data1
     1
DATA_0001
NAME
PATH
GROUP_NUMBER
/u02/data2
     1
DB1_CONTROL_0001
/u04/ctl2
     2
NAME
PATH
GROUP_NUMBER
DB1_CONTROL_0000
/u04/ctl1
     2
FRA_0000
/u06/fra1
     6
NAME
PATH
GROUP_NUMBER
FRA_0001
/u06/fra2
     6
DB1_DATA_0001
/u03/data2
NAME
PATH
GROUP_NUMBER
     4
DB1_DATA_0000
/u03/data1
     4
12 rows selected.