数据库无法启动ORA-01034: ORACLE not available

错误场景：

---

1、数据库未启动，查询v$instance报错

 SQL> select status from v$instance;
 select status from v$instance
 *
 ERROR at line 1:
 ORA-01034: ORACLE not available
 Process ID: 0
 Session ID: 0 Serial number: 0

v$instance视图都不能查询（该视图在nomount状态即可查询），意味着数据库没启动

2、启动数据库报错

 SQL> startup nomount;
 ORA-01078: failure in processing system parameters
 LRM-00109: could not open parameter file '/u01/app/oracle/product/11.2.0/dbhome_1/dbs/initdg_standby.ora'

报错找不到参数文件initdg_standby.ora，意味着找不到spfile，在参数文件目录查看：

 [oracle@zml-rhel6 ~]$ cd /u01/app/oracle/product/11.2.0/dbhome_1/dbs/
 [oracle@zml-rhel6 dbs]$ ll
 total 32
 -rw-rw---- 1 oracle oinstall 1544 Dec 22 15:53 hc_DBUA0.dat
 -rw-rw---- 1 oracle oinstall 1544 Dec 22 15:55 hc_dg01.dat
 -rw-rw---- 1 oracle oinstall 1544 Dec 22 16:10 hc_test.dat
 -rw-r--r-- 1 oracle oinstall 2851 May 15  2009 init.ora
 -rw-r----- 1 oracle oinstall   24 Dec 22 15:54 lkDG_01
 -rw-r----- 1 oracle oinstall 1536 Dec 22 15:55 orapwdg01
 -rw-r----- 1 oracle oinstall 2560 Feb  4 10:05 spfiledg01.ora
 -rw-r----- 1 oracle oinstall 3584 Dec 22 16:10 spfiletest.ora
 [oracle@zml-rhel6 dbs]$

可以看到该目录下有两个参数文件，sid分别为dg01,test，应该是环境变量ORACLE_SID设置的有问题

3、查看环境变量ORACLE_SID

 [oracle@zml-rhel6 ~]$ cat .bash_profile
 # .bash_profile

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

 # User specific environment and startup programs
 unset DISPLAY
 PATH=$PATH:$HOME/bin

 export PATH
 umask 

 export TMP=/u01/app/tmp
 export TMPDIR=/u01/app/tmp
 export ORACLE_BASE=/u01/app/oracle
 export ORACLE_SID=dg_standby
 export ORACLE_HOME=/u01/app/oracle/product/11.2./dbhome_1
 export PATH=$ORACLE_HOME/bin:$PATH
 export LD_LIBRARY_PATH=$ORACLE_HOME/lib

环境变量中的ORACLE_SID为dg_standby，应该是静默安装时部分参数含义未弄清楚导致设置错误

解决

---

1、修改ORACLE_SID环境变量为dg01

export ORACLE_SID=dg01 
source .bash_profile

2、启动数据库

 SQL> startup open
 ORACLE instance started.

 Total System Global Area 1603411968 bytes
 Fixed Size            2213776 bytes
 Variable Size          989857904 bytes
 Database Buffers      603979776 bytes
 Redo Buffers            7360512 bytes
 Database mounted.
 Database opened.

over！