unix/linux环境中Oracle RAC OFF和RAC ON

在某些情况下，在unix/linux上的Oracle crs无法启动，需要oracle以single instance启动的时候，可以重新编译（Relinking）oracle，关闭RAC特性，下面记录其方法：
RAC ON

1. Login as the Oracle software owner and shutdown all database instances on all nodes in the cluster.

2. cd $ORACLE_HOME/rdbms/lib

3. make -f ins_rdbms.mk rac_on

If this step did not fail with fatal errors then proceed to step 4.

4. make -f ins_rdbms.mk ioracle

RAC OFF 解除grid和数据库的关系，srvctl将无法操作数据库

1. Login as the Oracle software owner and shutdown all database instances on all nodes in the cluster.

2. cd $ORACLE_HOME/rdbms/lib

3. make -f ins_rdbms.mk rac_off

If this step did not fail with fatal errors, proceed to step 4.

4. make -f ins_rdbms.mk ioracle

来源：https://blog.51cto.com/214320/2432043