Instance "ORCL", status READY, has 1 handler(s) for this service...
Service "ORCL_XPT" has 1 instance(s).
Instance "ORCL", status READY, has 1 handler(s) for this service...
Service "PLSExtProc" has 1 instance(s).
Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
[oracle@whgg admin]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Feb 28 09:52:50 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SYS@ORCL>exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
[oracle@tyger admin]$ cd /u01/app/oracle/product/10.2.0/db_1/dbs/
[oracle@tyger dbs]$ ls
hc_ORCL.dat initdw.ora init.ora lkORCL orapwORCL spfileORCL.ora
[oracle@tyger dbs]$ sqlplus sys/oracle@ORCL as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Feb 28 09:53:51 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SYS@ORCL>
第二种情况：
参数SQLNET.AUTHENTICATION_SERVICES设置为 all -----------------------屏蔽口令认证都启用操作系统认证
[oracle@tyger admin]$ pwd
/u01/app/oracle/product/10.2.0/db_1/network/admin
[oracle@tyger admin]$ vim sqlnet.ora
NAME.DIRECTORY_PATH=(tnsnames,ezconnect)
SQLNET.AUTHENTICATION_SERVICES=(ALL)
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Feb 28 09:59:20 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SYS@ORCL>exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
[oracle@tyger admin]$ sqlplus sys/oracle@ORCL as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Feb 28 09:59:39 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
ERROR:
ORA-12641: Authentication service failed to initialize
Enter user-name:
第三种情况：
参数SQLNET.AUTHENTICATION_SERVICES 设置为 NONE 或NTS ----------------屏蔽操作系统认证都启用口令认证
[oracle@tyger admin]$ vim sqlnet.ora
NAME.DIRECTORY_PATH=(tnsnames,ezconnect)
SQLNET.AUTHENTICATION_SERVICES=(NTS)
[oracle@tyger admin]$ sqlplus / as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Feb 28 10:36:35 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
ERROR:
ORA-01031: insufficient privileges
[oracle@tyger admin]$ sqlplus sys/oracle@ORCL as sysdba
SQL*Plus: Release 10.2.0.1.0 - Production on Fri Feb 28 10:36:52 2014
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SYS@ORCL>
第四种情况：
当数据库屏蔽了操作系统认证，启用口令认证方式的话，需要检查remote_login_passwordfile参数，如果该参数设置为NONE,该值表示不使用口令文件，因此，此时数据库将不能登录
解决办法：启动操作系统认证，登录数据库后将remote_login_passwordfile参数修改EXCLUSIVE，然后再屏蔽操作系统认证，启用口令认证。
> remote_login_passwordfile参数可以设置为3个值 none、exclusive、shared