1、任意节点上启动到nomount状态
SQL> startup nomount

2、查看当前的控制文件
SQL> show parameter control

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
control_file_record_keep_time        integer     7
control_files                        string      +OCR/eisoo/controlfile/current
                                                 .260.901474585
control_management_pack_access       string      DIAGNOSTIC+TUNING

3、使用RMAN复制一份控制文件
RMAN> restore controlfile to '+DATA/eisoo/controlfile/current.276' from '+OCR/eisoo/controlfile/Current.260.901474585';   --新的控制文件名字不能指定标识符

SQL> alter system set control_files='+DATA/eisoo/controlfile/current.276.915716529','+OCR/eisoo/controlfile/Current.260.901474585' scope=spfile;

4、重新启动RAC数据库
bash-4.3$ srvctl start database -d eisoo

5、查看确认
SQL> show parameter control

NAME                                 TYPE                   VALUE
------------------------------------ ---------------------- ------------------------------
control_file_record_keep_time        integer                7
control_files                        string                 +DATA/eisoo/controlfile/curren
                                                            t.276.915716529, +OCR/eisoo/co
                                                            ntrolfile/current.260.90147458
                                                            5
control_management_pack_access       string                 DIAGNOSTIC+TUNING