第十步：找到alert日志，通过alert日志中的启动信息恢复pfile参数文件。
[oracle@ora11g dbs]$ cd /u01/app/oracle/diag/rdbms/cams/cams/trace/
[oracle@ora11g trace]$ ls | grep alert
alert_cams.log
找到最近几次成功的日志信息，选取其中正确无误的一条日志信息：
创建pfile文件initcams.ora，将alert日志中的参数信息填入：
[oracle@ora11g trace]$ cd $ORACLE_HOME/dbs
[oracle@ora11g dbs]$ ls
backup backup1 hc_cams.dat lkCAMS orapwcams
[oracle@ora11g dbs]$ vi initcams.ora
[oracle@ora11g dbs]$ cat initcams.ora
processes = 150
memory_target = 744M
control_files = "/u01/app/oracle/oradata/cams/control01.ctl"
control_files = "/u01/app/oracle/fast_recovery_area/cams/control02.ctl"
db_block_size = 8192
compatible = "11.2.0.4.0"
db_recovery_file_dest = "/u01/app/oracle/fast_recovery_area"
db_recovery_file_dest_size= 4182M
undo_tablespace = "UNDOTBS1"
remote_login_passwordfile= "EXCLUSIVE"
db_domain = ""
dispatchers = "(PROTOCOL=TCP) (SERVICE=camsXDB)"
job_queue_processes = 1000
audit_file_dest = "/u01/app/oracle/admin/cams/adump"
audit_trail = "DB"
db_name = "cams"
open_cursors = 300
diagnostic_dest = "/u01/app/oracle"
直接使用pfile文件启动数据库：
SYS@cams>startup pfile='/u01/app/oracle/product/11.2.0/db_1/dbs/initcams.ora';
ORACLE instance started.
Total System Global Area 776646656 bytes
Fixed Size 2257272 bytes
Variable Size 511708808 bytes
Database Buffers 255852544 bytes
Redo Buffers 6828032 bytes
Database mounted.
Database opened.
第十一步：这里假设第十步的alert日志中没找到参数信息，需要进行恢复，假设init.ora还能找到。
[oracle@ora11g backup]$ ls
initcams.ora init.ora spfilecams.ora
[oracle@ora11g backup]$ cat init.ora | grep -v ^# | grep -v ^$ > initcams.ora
[oracle@ora11g backup]$ cat initcams.ora
db_name='ORCL'
memory_target=1G
processes = 150
audit_file_dest='<ORACLE_BASE>/admin/orcl/adump'
audit_trail ='db'
db_block_size=8192
db_domain=''
db_recovery_file_dest='<ORACLE_BASE>/flash_recovery_area'
db_recovery_file_dest_size=2G
diagnostic_dest='<ORACLE_BASE>'
dispatchers='(PROTOCOL=TCP) (SERVICE=ORCLXDB)'
open_cursors=300
remote_login_passwordfile='EXCLUSIVE'
undo_tablespace='UNDOTBS1'
control_files = (ora_control1, ora_control2)
compatible ='11.2.0'
然后根据实际环境情况修改initcams.ora，启动数据库，不过可能会出现部分参数的值与原数据库不一致，需要DBA进行调整。
第十二步：这里假设第十步的alert日志中没找到参数信息，需要进行恢复，假设init.ora不能找到。
[oracle@ora11g dbs]$ vi initcams.ora
[oracle@ora11g dbs]$ cat initcams.ora
db_name='cams'
使用pfile启动数据库：
SYS@cams>shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@cams>startup pfile='/u01/app/oracle/product/11.2.0/db_1/dbs/initcams.ora';
ORACLE instance started.
Total System Global Area 263090176 bytes
Fixed Size 2252256 bytes
Variable Size 205521440 bytes
Database Buffers 50331648 bytes
Redo Buffers 4984832 bytes
ORA-00205: error in identifying control file, check alert log for more info
检查alert日志
[oracle@ora11g trace]$ tail -n 20 alert_cams.log
CKPT started with pid=12, OS id=5722
Wed Aug 02 14:38:15 2017
SMON started with pid=13, OS id=5724
Wed Aug 02 14:38:15 2017
RECO started with pid=14, OS id=5726
Wed Aug 02 14:38:15 2017
MMON started with pid=15, OS id=5728
Wed Aug 02 14:38:15 2017
MMNL started with pid=16, OS id=5730
ORACLE_BASE from environment = /u01/app/oracle
Wed Aug 02 14:38:15 2017
ALTER DATABASE MOUNT
ORA-00210: cannot open the specified control file
ORA-00202: control file: '/u01/app/oracle/product/11.2.0/db_1/dbs/cntrlcams.dbf'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3
ORA-205 signalled during: ALTER DATABASE MOUNT...
Wed Aug 02 14:38:15 2017
Checker run found 1 new persistent data failures
修改pfile文件，指定control_files参数（如果真的忘了，可以用linux命令查找）
[oracle@ora11g dbs]$ find $ORACLE_BASE -name control*
/u01/app/oracle/product/11.2.0/db_1/oc4j/j2ee/oc4j_applications/applications/em/em/images/database/storage/controlfile.gif
/u01/app/oracle/product/11.2.0/db_1/apex/images/fck/editor/dialog/fck_spellerpages/spellerpages/controlWindow.js
/u01/app/oracle/product/11.2.0/db_1/apex/images/fck/editor/dialog/fck_spellerpages/spellerpages/controls.html
/u01/app/oracle/fast_recovery_area/cams/control02.ctl
/u01/app/oracle/oradata/cams/control01.ctl
[oracle@ora11g dbs]$ vi initcams.ora
[oracle@ora11g dbs]$ cat initcams.ora
db_name='cams'
control_files='/u01/app/oracle/oradata/cams/control01.ctl','/u01/app/oracle/fast_recovery_area/cams/control02.ctl'
再次使用pfile启动数据库
SYS@cams>shutdown immediate;
ORA-01507: database not mounted
ORACLE instance shut down.
SYS@cams>startup;
ORACLE instance started.
Total System Global Area 263090176 bytes
Fixed Size 2252256 bytes
Variable Size 205521440 bytes
Database Buffers 50331648 bytes
Redo Buffers 4984832 bytes
ORA-00201: control file version 11.2.0.4.0 incompatible with ORACLE version
11.2.0.0.0
ORA-00202: control file: '/u01/app/oracle/oradata/cams/control01.ctl'
查看错误信息
[oracle@ora11g dbs]$ oerr ORA 00201
00201, 00000, "control file version %s incompatible with ORACLE version %s"
// *Cause: The control file was created by incompatible software.
// *Action: Either restart with a compatible software release or use
// CREATE CONTROLFILE to create a new control file that is
// compatible with this release.
这里需要在参数文件配置一个compatible参数
[oracle@ora11g dbs]$ vi initcams.ora
[oracle@ora11g dbs]$ cat initcams.ora
db_name='cams'
control_files='/u01/app/oracle/oradata/cams/control01.ctl','/u01/app/oracle/fast_recovery_area/cams/control02.ctl'
compatible="11.2.0.4.0"
再次使用pfile启动数据库
SYS@cams>shutdown immediate;
ORA-01507: database not mounted
ORACLE instance shut down.
SYS@cams>startup;
ORACLE instance started.
Total System Global Area 263090176 bytes
Fixed Size 2252256 bytes
Variable Size 205521440 bytes
Database Buffers 50331648 bytes
Redo Buffers 4984832 bytes
Database mounted.
Database opened.