解决ora-01034\\27101的方法

ora-00900

[oracle@oracle ~]$ sqlplus system/oracle

SQL*Plus: Release 10.2.0.1.0 - Production on Wed Jun 15 10:51:48 2011

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux Error: 2: No such file or directory


=========================================

原因：数据库还没有启动。
         应该这样启动：

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


SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus
[oracle@oracle ~]$ sqlplus / as sysdba

SQL*Plus: Release 10.2.0.1.0 - Production on Wed Jun 15 10:53:28 2011

Copyright (c) 1982, 2005, Oracle.  All rights reserved.

/etc/host.conf: line 1: bad command `192.168.1.155 oracle'
Connected to an idle instance.


         接下来输入
         SQL> startup
/etc/host.conf: line 1: bad command `192.168.1.155 oracle'
/etc/host.conf: line 1: bad command `192.168.1.155 oracle'
ORACLE instance started.

Total System Global Area  264241152 bytes
Fixed Size                  1218868 bytes
Variable Size              88082124 bytes
Database Buffers          171966464 bytes
Redo Buffers                2973696 bytes
Database mounted.
/etc/host.conf: line 1: bad command `192.168.1.155 oracle'
Database opened.
SQL> select * from V$version;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod
PL/SQL Release 10.2.0.1.0 - Production
CORE    10.2.0.1.0      Production
TNS for Linux: Version 10.2.0.1.0 - Production
NLSRTL Version 10.2.0.1.0 - Production
++++++++++++++++++++++++++==
请注意其中的‘/etc/host.conf: line 1: bad command `192.168.1.155 oracle'’
是因为`192.168.1.155 oracle'’不因该放在／etc/host.conf里，而是应放在/etc/hosts中如下：
/etc/host.conf
order hosts,bind(默认保持不变)

修改/etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
192.168.1.155 localhost.localdomain     oracle
::1     localhost6.localdomain6 localhost6