ORA-15032 ORA-15034 add diskgroup disk fail

Problem:

SQL> alter diskgroup datadg add site siteb failgroup fg2 disk '/dev/oracleasm/DATA01_2' name DATA01_2 force site siteb failgroup fg2 disk '/dev/oracleasm/DATA02_2' name DATA02_2 force rebalance wait;
alter diskgroup datadg add site siteb failgroup fg2 disk '/dev/oracleasm/DATA01_2' name DATA01_2 force site siteb failgroup fg2 disk '/dev/oracleasm/DATA02_2' name DATA02_2 force rebalance wait
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ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15034: disk '/dev/oracleasm/DATA01_2' does not require the FORCE option
ORA-15034: disk '/dev/oracleasm/DATA02_2' does not require the FORCE option

Solution: remove force option

SQL> alter diskgroup datadg add site siteb failgroup fg2 disk '/dev/oracleasm/DATA01_2' name DATA01_2 site siteb failgroup fg2 disk '/dev/oracleasm/DATA02_2' name DATA02_2 rebalance wait;