ORA-01102: cannot mount database in EXCLUSIVE mode

安装完ORACEL 10g数据库后,启动数据库时遇到ORA-01102: cannot mount database in EXCLUSIVE mode

[oracle@DB-Server ~]$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Thu Apr 10 13:53:08 2014

Copyright (c) 1982, 2005, Oracle. All rights reserved.

Connected to an idle instance.

SQL> startup

ORACLE instance started.

Total System Global Area 5033164800 bytes

Fixed Size 2027672 bytes

Variable Size 905973608 bytes

Database Buffers 4110417920 bytes

Redo Buffers 14745600 bytes

ORA-01102: cannot mount database in EXCLUSIVE mode

查看告警日志文件，发现有ORA-09968: unable to lock file 和Linux-x86_64 Error: 11: Resource temporarily unavailable等错误

[oracle@DB-Server bdump]$ tail -20f alert_epps.log

SMON started with pid=8, OS id=24482

RECO started with pid=9, OS id=24484

CJQ0 started with pid=10, OS id=24486

MMON started with pid=11, OS id=24488

Thu Apr 10 13:53:42 2014

starting up 1 dispatcher(s) for network address '(ADDRESS=(PARTIAL=YES)(PROTOCOL=TCP))'...

MMNL started with pid=12, OS id=24490

Thu Apr 10 13:53:42 2014

starting up 1 shared server(s) ...

Thu Apr 10 13:53:42 2014

ALTER DATABASE MOUNT

Thu Apr 10 13:53:42 2014

sculkget: failed to lock /u01/app/oracle//product/10.2.0/db_1/dbs/lkEPPS exclusive

sculkget: lock held by PID: 20337

Thu Apr 10 13:53:42 2014

ORA-09968: unable to lock file

Linux-x86_64 Error: 11: Resource temporarily unavailable

Additional information: 20337

Thu Apr 10 13:53:42 2014

ORA-1102 signalled during: ALTER DATABASE MOUNT...

'

第一次遇到这种情况，于是网上搜索了一下资料，找到一篇相关文章http://blog.itpub.net/12272958/viewspace-716020，介绍了出现这种错误的三种情况：

      a、 Oracle的共享内存段或信号量没有被释放；

      b、 Oracle的后台进程（如SMON、PMON、DBWn等）没有被关闭；

      c、 用于锁内存的文件lk<sid>和sgadef<sid>.dbf文件没有被删除。

看了文章前面一部分。便武断的觉得应该是第三者情况（由于告警日志中出现了相关信息）：“用于锁内存的文件lk<sid>和sgadef<sid>.dbf文件没有被删除”。于是动手操作（太心急，这毛病老是难以改变），关闭数据库实例，删除/u01/app/oracle/product/10.2.0/db_1/dbs/lkEPPS文件后，重新启动数据库。结果作者的经历又在我身上重演了一次。

启动时候报ORA-00205错误

SQL> shutdown immediate;

ORA-01507: database not mounted

ORACLE instance shut down.

SQL> startup

ORACLE instance started.

Total System Global Area 5033164800 bytes

Fixed Size 2027672 bytes

Variable Size 905973608 bytes

Database Buffers 4110417920 bytes

Redo Buffers 14745600 bytes

ORA-00205: error in identifying control file, check alert log for more info

查看告警日志，有如下错误信息：

RECO started with pid=9, OS id=24887

CJQ0 started with pid=10, OS id=24889

MMON started with pid=11, OS id=24891

Thu Apr 10 14:04:05 2014

starting up 1 dispatcher(s) for network address '(ADDRESS=(PARTIAL=YES)(PROTOCOL=TCP))'...

MMNL started with pid=12, OS id=24894

Thu Apr 10 14:04:06 2014

starting up 1 shared server(s) ...

Thu Apr 10 14:04:06 2014

ALTER DATABASE MOUNT

Thu Apr 10 14:04:06 2014

ORA-00202: control file: '/u01/app/oracle/oradata/epps/control01.ctl'

ORA-27086: unable to lock file - already in use

Linux-x86_64 Error: 11: Resource temporarily unavailable

Additional information: 8

Additional information: 20341

Thu Apr 10 14:04:09 2014

ORA-205 signalled during: ALTER DATABASE MOUNT...

于是索性静下心来多了解一下这个问题，在网上查看了大量关于ORA-01102的文章。这篇博客http://blog.itpub.net/20674423/viewspace-711545对这个问题阐述得比较清晰。下面是Metalink关于ORA-01102的解释以及解决方法：

Problem Description:

====================

You are trying to startup the database and you receive the following error:

ORA-01102: cannot mount database in EXCLUSIVE mode

Cause: Some other instance has the database mounted exclusive or shared.

Action: Shutdown other instance or mount in a compatible mode.

Problem Explanation:

====================

A database is started in EXCLUSIVE mode by default. Therefore, the ORA-01102 error is misleading and may have occurred due to one of the following reasons:

- there is still an "sgadef<sid>.dbf" file in the "ORACLE_HOME/dbs"  directory

- the processes for Oracle (pmon, smon, lgwr and dbwr) still exist

- shared memory segments and semaphores still exist even though the

database has been shutdown

- there is a "ORACLE_HOME/dbs/lk<sid>" file

Search Words:

=============

ORA-1102, crash, immediate, abort, fail, fails, migration

Solution Description:

=====================

Verify that the database was shutdown cleanly by doing the following:

1. Verify that there is not a "sgadef<sid>.dbf" file in the directory "ORACLE_HOME/dbs".

        % ls $ORACLE_HOME/dbs/sgadef<sid>.dbf  If this file does exist, remove it.

        % rm $ORACLE_HOME/dbs/sgadef<sid>.dbf

2. Verify that there are no background processes owned by "oracle"

       % ps -ef | grep ora_ | grep $ORACLE_SID

If background processes exist, remove them by using the Unix

command "kill". For example:

     % kill -9 <rocess_ID_Number>

3. Verify that no shared memory segments and semaphores that are owned by "oracle" still exist

% ipcs -b

If there are shared memory segments and semaphores owned by "oracle", remove the shared memory segments

        % ipcrm -m <Shared_Memory_ID_Number>

and remove the semaphores

       % ipcrm -s <Semaphore_ID_Number>

NOTE: The example shown above assumes that you only have one

database on this machine. If you have more than one

database, you will need to shutdown all other databases

before proceeding with Step 4.

4. Verify that the "$ORACLE_HOME/dbs/lk<sid>" file does not exist

5. Startup the instance

Solution Explanation:

=====================

The "lk<sid>" and "sgadef<sid>.dbf" files are used for locking shared memory. It seems that even though no memory is allocated, Oracle thinks memory is still locked. By removing the "sgadef" and "lk" files you remove any knowledge oracle has of shared memory that is in use. Now the database can start.

参考资料：

http://blog.itpub.net/12272958/viewspace-716020

http://blog.itpub.net/20674423/viewspace-711545