		现象： 
	

		RAC建库的时候，由于节点2的redo出问题，导致节点2实例不能mount。 
	

		SQL> alter database mount;
	

		alter database mount
	

*

		ERROR at line 1:
	

		ORA-01618: redo thread 2 is not enabled - cannot mount
	

		错误说明： 
	

		[oracle@rac2 bin]$ oerr ora 01618
	

		01618, 00000, "redo thread %s is not enabled - cannot mount"
	

		// *Cause:  The INIT.ORA parameter "thread" requests a thread that is not
	

		//          enabled. A thread must be enabled before it can be mounted.
	

		// *Action: Shutdown the instance, change the INIT.ORA parameter and startup
	

		//          mounting a different thread. If the database is open in another
	

		//          instance then the thread may be enabled.
	

		解决方法： 
	

		在另一个能打开的节点执行 
	

		SQL> alter database add logfile thread 2 ('+DATA1') size .....;
	

		Database altered.
	

		SQL> alter database add logfile thread 2 ('+DATA1') size .....;
	

		Database altered.
	

		SQL> alter database enable thread 2; 
	

		Database altered.
	

		然后打开节点2 
	

		SQL> alter database mount;
	

		Database altered.
	

		SQL> alter database open;
	

		Database altered.
	

ITPub博客

ORA-01618: redo thread 2 is not enabled - cannot mount