一、问题描述：单位一套测试Oracle数据库，本想用DBCA看看数据库配置信息，当然也是手闲得慌，谁想到竟然出现下面的画面。创建新的数据，配置数据库操作按键是灰色，不让点击。这是什么情况，实例没有启动，不可能啊 ，刚刚还登录过呢。好吧，开始处理过程之旅。

二、处理方法：

1. 检查/etc/oratab文件 ，发现关于路径的信息都是之前安装的ORACLE软件目录(/u01/.....)与现在的软件目录(/home/oracle/app/.....)不一致。

修改前：

[oracle@tora01 etc]$ cat oratab

#

# This file is used by ORACLE utilities.  It is created by root.sh

# and updated by either Database Configuration Assistant while creating

# a database or ASM Configuration Assistant while creating ASM instance.

# A colon, ':', is used as the field terminator.  A new line terminates

# the entry.  Lines beginning with a pound sign, '#', are comments.

#

# Entries are of the form:

#  $ORACLE_SID:$ORACLE_HOME::

#

# The first and second fields are the system identifier and home

# directory of the database respectively.  The third filed indicates

# to the dbstart utility that the database should , "Y", or should not,

# "N", be brought up at system boot time.

#

# Multiple entries with the same $ORACLE_SID are not allowed.

#

#

holytest:/u01/app/oracle/product/11.2.0/db_1:N

修改后：

[oracle@tora01 etc]$ cat oratab

#

# This file is used by ORACLE utilities.  It is created by root.sh

# and updated by either Database Configuration Assistant while creating

# a database or ASM Configuration Assistant while creating ASM instance.

# A colon, ':', is used as the field terminator.  A new line terminates

# the entry.  Lines beginning with a pound sign, '#', are comments.

#

# Entries are of the form:

#  $ORACLE_SID:$ORACLE_HOME::

#

# The first and second fields are the system identifier and home

# directory of the database respectively.  The third filed indicates

# to the dbstart utility that the database should , "Y", or should not,

# "N", be brought up at system boot time.

#

# Multiple entries with the same $ORACLE_SID are not allowed.

#

#

holytest:/home/oracle/app/oracle/product/11.2.0/dbhome_1:N

2. 再次启动DBCA进行验证，发现恢复正常

三、总结：一次小小的发现，对oratab文件的了解又深入了一点点。该文件最后那个N，如果你需要数据自动启动的话，要改为Y，这些都是经验啊，还要继续努力学习。