To Find ASM Disk Usage in Database

 set lines 255
 col path for a35
 col Diskgroup for a15
 col DiskName for a20
 col disk# for 999
 col total_mb for 999,999,999
 col free_mb for 999,999,999
 compute sum of total_mb on DiskGroup
 compute sum of free_mb on DiskGroup
 break on DiskGroup skip 1 on report -

 set pages 255
 select a.name DiskGroup, b.disk_number Disk#, b.name DiskName, b.total_mb, b.free_mb, b.path, b.header_status
 from v$asm_disk b, v$asm_diskgroup a
 where a.group_number (+) =b.group_number
 order by b.group_number, b.disk_number, b.name
  /


Happy Learning ....