Oracle中su切换进去sqlplus登录失败的问题处理

问题描述：
生产环境的Oracle数据库突然登录不上去了，rlwrap生产环境的oracle数据库突然登录不上去了，rlwrap sqlplus "/ as sysdba"报错如下：rlwrap
[oracle@localhost root]$ rlwrap sqlplus "/ as sysdba"
rlwrap: warning: your $TERM is 'xterm' but rlwrap couldn't find it in the terminfo database. Expect some problems.
rlwrap: Cannot execute sqlplus: Permission denied
[oracle@localhost root]$ sqlplus "/ as sysdba"
bash: sqlplus: command not found
[oracle@localhost root]$

1，oracle登录报错
[oracle@localhost root]$  rlwrap sqlplus "/ as sysdba"
Error 6 initializing SQL*Plus
SP2-0667: Message file sp1<lang>.msb not found
SP2-0750: You may need to set ORACLE_HOME to your Oracle software directory
[oracle@localhost root]$
[oracle@localhost root]$

2，查看ORACLE_HOME变量，为空值
[oracle@localhost root]$ echo $ORACLE_HOME

[oracle@localhost root]$

3，在/etc/profile设置ORACLE_HOME变量
[root@localhost ~]# vim /etc/profile
export ORACLE_HOME=/opt/oracle/app/oracle/product/11.2.0/dbhome_1

[root@localhost ~]# source /etc/profile
[root@localhost ~]# su oracle
[oracle@localhost root]$
[oracle@localhost root]$ echo $ORACLE_HOME
/oracle/app/oracle/product/11.2.0/dbhome_1/
[oracle@localhost root]$

4，ORACLE_HOME环境变量有值了，再去用sqlplus登录一下，试试看
[oracle@localhost root]$ rlwrap sqlplus "/ as sysdba"
rlwrap: warning: your $TERM is 'xterm' but rlwrap couldn't find it in the terminfo database. Expect some problems.
rlwrap: Cannot execute sqlplus: Permission denied
[oracle@localhost root]$

5，做一下sqlplus的软连接
[oracle@localhost root]$ exit
exit
[root@localhost ~]# ln -s $ORACLE_HOME/bin/sqlplus /usr/bin
[root@localhost ~]# su oracle
[oracle@localhost root]$ sqlplus "/ as sysdba"

SQL*Plus: Release 11.2.0.1.0 Production on Fri Jan 16 10:19:39 2015

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

ERROR:
ORA-12162: TNS:net service name is incorrectly specified

Enter user-name:
ERROR:
ORA-12162: TNS:net service name is incorrectly specified

Enter user-name:
ERROR:
ORA-12162: TNS:net service name is incorrectly specified

SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus
[oracle@localhost root]$
[oracle@localhost root]$ echo $ORACLE_SID

[oracle@localhost root]$
系统环境变量里面没有ORACLE_SID

6，设置ORACLE_SID
[oracle@localhost root]$ exit
exit
[root@localhost ~]# vim /etc/profile
export ORACLE_HOME=/oracle/app/oracle/product/11.2.0/dbhome_1/
export ORACLE_SID=pxxerxxs
[root@localhost ~]#  source /etc/profile

[oracle@localhost root]$ exit
exit
[root@localhost ~]# vim /etc/profile
[root@localhost ~]# source /etc/profile
[root@localhost ~]# su oracle
[oracle@localhost root]$ rlwrap sqlplus "/ as sysdba"
rlwrap: warning: your $TERM is 'xterm' but rlwrap couldn't find it in the terminfo database. Expect some problems.
                                                                                                                                                                                              SQL*Plus: Release 11.2.0.1.0 Production on Fri Jan 16 10:25:33 2015

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to an idle instance.                                                                                                                                                               

SQL>                                                                                                                                                                                         
SQL>                                                                                                                                                                                         
SQL>

7，去oracle用户下查看系统变量
[oracle@localhost root]$ cat ~/.bash_profile
# .bash_profile

# Get the aliases and functions
if [ -f ~/.bashrc ]; then
. ~/.bashrc
fi

# User specific environment and startup programs

PATH=$PATH:$HOME/bin

export PATH

#added for oracle
export ORACLE_BASE=/oracle/app/oracle
export ORACLE_HOME=/oracle/app/oracle/product/11.2.0/dbhome_1
export ORACLE_SID=pxxerxxs
export TNS_ADMIN=$ORACLE_HOME/network/admin

export PATH=$PATH:$ORACLE_HOME/bin
[oracle@localhost root]$
配置里面有值，问题在哪里？

8，su的时候有差异
不加-的话的话只是切换用户 不去更换用户的配置，加上-后 再去sqlplus 试试
[oracle@localhost ~]$ exit
logout
[root@localhost ~]# su oracle
[oracle@localhost root]$ echo $ORACLE_BASE

[oracle@localhost root]$ exit
exit
[root@localhost ~]# su - oracle
[oracle@localhost ~]$ echo $ORACLE_BASE
/oracle/app/oracle
[oracle@localhost ~]$

9，验证下su - oracle
[oracle@localhost ~]$ rlwrap sqlplus "/ as sysdba"
rlwrap: warning: your $TERM is 'xterm' but rlwrap couldn't find it in the terminfo database. Expect some problems.
                                                                                                                                                                                             
SQL*Plus: Release 11.2.0.1.0 Production on Fri Jan 16 10:36:51 2015

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options

SQL>

10，OK，尝试使用非sys账号登录报错
[oracle@localhost ~]$ rlwrap sqlplus "plas_prd/plrd_1628@pxxerxxs as sysdba"
rlwrap: warning: your $TERM is 'xterm' but rlwrap couldn't find it in the terminfo database. Expect some problems.

SQL*Plus: Release 11.2.0.1.0 Production on Fri Jan 16 16:53:11 2015

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

ERROR:
ORA-12154: TNS:could not resolve the connect identifier specified

Enter user-name:                                                                                                                                                                             
ERROR:
ORA-01017: invalid username/password; logon denied

Enter user-name:                                                                                                                                                                             
[oracle@localhost ~]$

11，去check下，tnsping pxxerxxs 能否成功
[oracle@localhost ~]$ tnsping  pxxerxxs

TNS Ping Utility for Linux: Version 11.2.0.1.0 - Production on 16-JAN-2015 16:53:27

Copyright (c) 1997, 2009, Oracle.  All rights reserved.

Used parameter files:
/oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/sqlnet.ora

TNS-03505: Failed to resolve name
[oracle@localhost ~]$
tnsping失败，得知pxxerxxs这个失效

12，去找tnsnames.ora
[oracle@localhost admin]$  more /oracle/app/oracle/product/11.2.0/dbhome_1/network/admin/tnsnames.ora
也可以more $ORACLE_HOME/network/admin/tnsnames.ora
找到
MPMD2 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.110.107)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME= pxxerxxs)
    )
  )

然后用非sys用户登录
[oracle@localhost ~]$ rlwrap sqlplus "pxxerxxsk/pa141215@MPMD2"
rlwrap: warning: your $TERM is 'xterm' but rlwrap couldn't find it in the terminfo database. Expect some problems.

SQL*Plus: Release 11.2.0.1.0 Production on Fri Jan 16 20:30:30 2015

Copyright (c) 1982, 2009, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, Oracle Label Security, OLAP, Data Mining,
Oracle Database Vault and Real Application Testing options

SQL>

OK登录显示成功。

总结，
（1）linux系统里面，su切换到oracle用户的时候，加上-就会更换oracle用户单独配置生效，如果不加-就不会使用oracle用户单独的配置。
（2）在使用sqlplus登录的时候，用非sys用户登录，@后面的是$ORACLE_HOME/network/admin/tnsnames.ora定义的那个前缀符号MPMD2，而不是SERVICE_NAME所指的oracle_sid，tnsnames.ora中MPMD2前缀定义如下所示
MPMD2 =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.110.101)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME= pxxerxxs)
    )
  )