问题：
启动数据库的时候报错如下：
SQL> startup
ORA-01078: failure in processing system parameters
ORA-01565: error in identifying file '+DATA/orcl/spfileorcl.ora'
ORA-17503: ksfdopn:2 Failed to open file +DATA/orcl/spfileorcl.ora
ORA-15077: could not locate ASM instance serving a required diskgroup -----------------由该信息我们可以推测，可能是ASM实例有问题了。
SQL> exit
Disconnected
查看一下相关的配置文件和设备文件，将属主设置正确：
修改设备权限：
[root@oraserver ~]# chown oracle:dba -R /dev/oracleasm
[root@oraserver ~]# chown oracle:dba -R /dev/raw
[root@rac1 ~]# vi /etc/udev/permissions.d/50-udev.permissions
# raw devices
ram*:root:disk:0660
#raw/*:root:disk:0660
raw/*:oracle:dba:0660
然后先启动ASM，再启动数据库
[oracle@oraserver ~]$ export ORACLE_SID=+ASM
[oracle@oraserver ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.1.0 - Production on Wed Aug 15 17:31:51 2012
Copyright (c) 1982, 2005, Oracle. All rights reserved.
SQL> conn / as sysdba
Connected to an idle instance. -------------由此看出，ASM实例确实是没启动。
SQL> startup
ASM instance started
Total System Global Area 83886080 bytes
Fixed Size 1217836 bytes
Variable Size 57502420 bytes
ASM Cache 25165824 bytes
ASM diskgroups mounted
SQL> exit
Disconnected from Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
[oracle@oraserver ~]$ export ORACLE_SID=orcl --------------一定不要忘了将环境变量修改回来，改成数据库实例的。
[oracle@oraserver ~]$ sqlplus /nolog
SQL*Plus: Release 10.2.0.1.0 - Production on Wed Aug 15 17:32:23 2012
Copyright (c) 1982, 2005, Oracle. All rights reserved.
SQL> conn / as sysdba
Connected to an idle instance.
SQL> startup
ORACLE instance started.
Total System Global Area 436207616 bytes
Fixed Size 1219856 bytes
Variable Size 130024176 bytes
Database Buffers 301989888 bytes
Redo Buffers 2973696 bytes
Database mounted.
Database opened.
SQL>
OK！~~~