1.檢查確認要刪除的磁碟組是否在用
select * from dba_data_files;
select * from dba_temp_files;
select * from v$logfile;
2.先在各節點上dismount磁碟組
alter diskgroup REDO01 dismount;
alter diskgroup REDO02 dismount;
alter diskgroup REDODG1 dismount;
3.ASM中刪除磁碟組
drop diskgroup REDO01 force including contents;
drop diskgroup REDO02 force including contents;
drop diskgroup REDODG1 force including contents;
4.crs刪除磁碟組
crsctl stat res -t  ---檢視磁碟組
srvctl remove diskgroup -g REDO01 -f
srvctl remove diskgroup -g REDO02 -f
srvctl remove diskgroup -g REDODG1 -f
5.更新crs資訊
檢視crs依賴的磁碟組：
crsctl status res ora.veraa.db -f
START_DEPENDENCIES=hard(ora.testDG1.dg,ora.testDG2.dg,ora.REDODG1.dg,ora.testDG3.dg,ora.REDO01.dg,ora.REDO02.dg,ora.REDODG01.dg) weak(type:ora.listener.type,global:type:ora.scan_listener.type,uniform:ora.ons,global:ora.gns) pullup(ora.testDG1.dg,ora.testDG2.dg,ora.REDODG1.dg,ora.testDG3.dg,ora.REDO01.dg,ora.REDO02.dg,ora.REDODG01.dg)
START_TIMEOUT=600
STATE_CHANGE_TEMPLATE=
STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.testDG1.dg,shutdown:ora.testDG2.dg,shutdown:ora.REDODG1.dg,shutdown:ora.testDG3.dg,shutdown:ora.REDO01.dg,shutdown:ora.REDO02.dg,shutdown:ora.REDODG01.dg)
修改正確的磁碟組：
srvctl modify database -d veraa -a "testDG1,testDG2,testDG3,REDODG01"