oracle10g_asm_v$asm_disk之total_mb_free_mb_required_mirror_free_mb相互關係

select name,type,total_mb,free_mb,required_mirror_free_mb,usable_file_mb
  2  from v$asm_diskgroup
  3* where type='NORMAL';
AME                           TYPE     TOTAL_MB    FREE_MB
------------------------------ ------ ---------- ----------
REQUIRED_MIRROR_FREE_MB USABLE_FILE_MB
----------------------- --------------
DG8                            NORMAL        576        474
                      0            237

DG_1                           NORMAL       2048       1336
                      0            668

1,只適用於normal and high redundancy
2,列間關係為：   
       FREE_MB - REQUIRED_MIRROR_FREE_MB = 2 * USABLE_FILE_MB

Disk Group Type	Maximum File Size
External redundancy	35 TB
Normal redundancy	5.8 TB
High redundancy	3.9 TB