[oracle@rac1 ~]$ export ORACLE_SID=A --设置ORACLE_HOME以后，可以简单的测试是否sqlplus一切正常
[oracle@rac1 ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.3.0 Production on Tue Nov 18 04:34:08 2014
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Connected to an idle instance.