一、错误描述
需要增加一个控制文件，进行了如下操作：
1、修改参数
alter system set control_files = '+DATA/orcl/controlfile/current.260.1070471991',
'+BAK/orcl/controlfile/current.256.1070471991',
'+bak/ctl_files/controlfile.256.1070471991'
scope = spfile sid = '*';
2、复制控制文件到 control_files 参数指定的位置
使用asmcmd 在执行 cp 命令时出现如下错误：
ASMCMD> cp +bak/orcl/controlfile/Current.256.1070471991 +bak/ctl_files/controlfile.256.1070471991
copying +bak/orcl/controlfile/Current.256.1070471991 -> +bak/ctl_files/controlfile.256.1070471991
ASMCMD-8016: copy source '+bak/orcl/controlfile/Current.256.1070471991' and target '+bak/ctl_files/controlfile.256.1070471991' failed
ORA-15056: additional error message
ORA-15046: ASM file name '+bak/ctl_files/controlfile.256.1070471991' is not in single-file creation form
ORA-06512: at "SYS.X$DBMS_DISKGROUP", line 415
ORA-06512: at line 3 (DBD ERROR: OCIStmtExecute)
二、错误产生的原因及解决办法
用户在asmcmd 中复制文件时不能指定文件后面的数值。命令修改为如下格式：
ASMCMD> cp '+BAK/orcl/controlfile/current.256.1070471991' '+bak/ctl_files/control_bak.ctl'
copying +BAK/orcl/controlfile/current.256.1070471991 -> +bak/ctl_files/control_bak.ctl
复制成功，查看文件：
ASMCMD> ls +bak/ctl_files
control_bak.ctl
# 用 ls -l 查看文件
# 发现在 ASM 中复制文件其实只是在目标目录下存储了一个 alias（别名），真正的文件被 ASM 放到了其他位置
ASMCMD> ls -l +bak/ctl_files
Type Redund Striped Time Sys Name
N control_bak.ctl => +BAK/ASM/CONTROLFILE/control_bak.ctl.265.1079800929
把数据库启动到 nomount，修改参数文件如下：
alter system set control_files = '+DATA/orcl/controlfile/current.260.1070471991',
'+BAK/orcl/controlfile/current.256.1070471991',
'+bak/ctl_files/control_bak.ctl'
scope = spfile sid = '*';
重启数据库，问题解决：
SQL> startup force
ORACLE instance started.
Total System Global Area 835104768 bytes
Fixed Size 2257840 bytes
Variable Size 603982928 bytes
Database Buffers 226492416 bytes
Redo Buffers 2371584 bytes
Database mounted.
Database opened.