SQL> startup
ORACLE instance started.
Total System Global Area 1068937216 bytes
Fixed Size 2220200 bytes
Variable Size 708841304 bytes
Database Buffers 352321536 bytes
Redo Buffers 5554176 bytes
ORA-00205: error in identifying control file, check alert log for more info
查看日志发现 启动的时候指定的控制文件指定错了，更改oracle 的启动控制文件
tail -f /u01/app/oracle/diag/rdbms/orcl/orcl/trace/alert_orcl.log
. 查看告警日志
这个问题通常与控制文件有关。请检查Oracle的告警日志（通常位于[Oracle Home]/diag/rdbms/[db_name]/[Instance_name]/trace目录下，文件名通常是alert_[Instance_name].log），以获取更多信息。
SQL> SELECT name FROM v$controlfile;
no rows selected
SQL> ALTER SYSTEM SET control_files = '/u01/app/oracle/oradata/orcl/control01.ctl' SCOPE=SPFILE;
System altered.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
Total System Global Area 1068937216 bytes
Fixed Size 2220200 bytes
Variable Size 708841304 bytes
Database Buffers 352321536 bytes
Redo Buffers 5554176 bytes
Database mounted.
Database opened.