https://mdinh.wordpress.com/2018/08/05/recreate-asm-disks-rac/
[oracle@rac2 ~]$ asmcmd lsdsk -G DATA
Path
/dev/oracleasm/disks/DISK
/dev/oracleasm/disks/FRA
[oracle@rac2 ~]$ asmcmd -p
ASMCMD [+] > lsdg
State Type Rebal Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB Offline_disks Voting_files Name
MOUNTED EXTERN N 512 4096 1048576 71319 69503 0 69503 0 N DATA/
ASMCMD [+] >
[oracle@rac2 ~]$ asmcmd lsdsk -G DATA
Path
/dev/oracleasm/disks/DISK
/dev/oracleasm/disks/FRA
[oracle@rac2 ~]$ asmcmd -p
ASMCMD [+] > lsdg
State Type Rebal Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB Offline_disks Voting_files Name
MOUNTED EXTERN N 512 4096 1048576 71319 69503 0 69503 0 N DATA/
ASMCMD [+] >
+++ Remove DG from Cluster. [oracle@racnode-dc1-1 sql]$ srvctl remove diskgroup -diskgroup DATA -force [oracle@racnode-dc1-1 sql]$ srvctl remove diskgroup -diskgroup FRA -force