[oracle@readhatAS53 etc]$ cat /etc/oratab
#

# This file is used by ORACLE utilities.  It is created by root.sh
# and updated by the Database Configuration Assistant when creating
# a database.

# 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:<N|Y>:
#
# 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 $ORACLE_SID are not allowed.
#
#
ORCL:/u01/oracle/product/ora10g:Y
當$ORACLE_SID:$ORACLE_HOME:<N|Y> 設置為Y時，允許實例自啟動，當設置為N時，則不允許自啟動。 這個文件里的配置僅僅起一個開關的作用，其并不會具體的執行啟動和關閉，具體的操作由$ORACLE_HOME/bin/dbstart和dbshut 腳本來實現。 這2個腳本在執行時會檢查/etc/oratab 文件里的配置，為Y時才能繼續執行。因此只要將ORCL:/u01/oracle/product/ora10g:N修改為Y就行了。
2、使用root用戶在/etc/rc.d/rc.local這個文件中添加如下內容：

#!/bin/sh
#
# This script will be executed *after* all the other init scripts.
# You can put your own initialization stuff in here if you don't
# want to do the full Sys V style init stuff.

touch /var/lock/subsys/local
su - oracle -c'lsnrctl start'//啟動oracle數據庫監聽
su - oracle -c'/u01/oracle/product/ora10g/bin/dbstart start'//啟動oracle數據庫實例
su - oracle -c'/opt/tomcat/apache-tomcat-6.0.20/bin/startup.sh'//啟動tomcat服務器的配置。

3、reboot系統，oracle數據庫與tomcat服務器就可以自動啟動了。