Create/Drop Diskgroup

Cleanup Diskgroup Cluster resources

 Drop diskgroup resource with srvctl 
[grid@grac41 ASM]$ srvctl status diskgroup -g ACFS
Disk Group ACFS is not running

[grid@grac41 ASM]$ srvctl remove diskgroup -g ACFS
PRCA-1002 : Failed to remove CRS resource ora.ACFS.dg for ASM Disk Group ACFS
PRCR-1028 : Failed to remove resource ora.ACFS.dg
PRCR-1072 : Failed to unregister resource ora.ACFS.dg
CRS-0222: Resource 'ora.ACFS.dg' has dependency error.

[grid@grac41 ASM]$  crsctl status resource ora.grac4.db -p | grep -i  acfs
START_DEPENDENCIES=hard(ora.DATA.dg,ora.FRA2.dg,ora.ACFS.dg) weak(type:ora.listener.type,global:type:ora.scan_listener.type,uniform:ora.ons,global:ora.gns) pullup(ora.DATA.dg,ora.FRA2.dg,ora.ACFS.dg)
STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DATA.dg,shutdown:ora.FRA2.dg,shutdown:ora.ACFS.dg)

Remove start dependency:
[root@grac41 ~]# crsctl  modify resource  ora.grac4.db  -attr "START_DEPENDENCIES='hard(ora.DATA.dg,ora.FRA2.dg) 
                 weak(type:ora.listener.type,global:type:ora.scan_listener.type,uniform:ora.ons,global:ora.gns) pullup(ora.DATA.dg,ora.FRA2.dg)' "
Check status :
[root@grac41 ~]#   crsctl status resource ora.grac4.db -p | grep -i acfs
STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DATA.dg,shutdown:ora.FRA2.dg,shutdown:ora.ACFS.dg)

--> STOP DEPENDENCIES still there
Remove stop dependency:
[root@grac41 ~]# crsctl  modify resource  ora.grac4.db  -attr "STOP_DEPENDENCIES='hard(intermediate:ora.asm,shutdown:ora.DATA.dg,shutdown:ora.FRA2.dg)' "
[root@grac41 ~]# crsctl status resource ora.grac4.db -p | grep -i acfs 
--> START and STOP DEPENDENCIES for DG ACFS are removed now

Finally delete the DG resoure 
$ srvctl remove diskgroup -g ACFS 

[grid@grac41 ASM]$ srvctl status diskgroup -g ACFS
PRCA-1000 : ASM Disk Group ACFS does not exist
PRCR-1001 : Resource ora.ACFS.dg does not exist