Oracle RAC ASM disk group to delete

1. Check whether you want to delete the disk group with

select * from dba_data_files;
select * from dba_temp_files;
select * from v$logfile;

2. First dismount the disk group on each node

alter diskgroup REDO01 dismount;
alter diskgroup REDO02 dismount;
alter diskgroup REDODG1 dismount;

Removing a disk group 3.ASM

drop diskgroup REDO01 force including contents;
drop diskgroup REDO02 force including contents;
drop diskgroup REDODG1 force including contents;

4.crs delete disk groups

crsctl stat res -t  ---查看磁盘组
srvctl remove diskgroup -g REDO01 -f
srvctl remove diskgroup -g REDO02 -f
srvctl remove diskgroup -g REDODG1 -f

5. Update the information crs
View crs dependent disk group:

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)

Modify the correct disk group:
srvctl modify database -d veraa -a "testDG1,testDG2,testDG3,REDODG01"