一、问题描述：单位一套测试数据库，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：