环境：RHEL6.5 + Oracle11.2.0.4 双节点RAC

故障现象：节点1实例没有启动成功，节点2正常启动。

1.故障现象

主机网卡故障，导致rac节点1异常停止，启动rac节点1时候报错。

尝试启动RAC 节点1，遭遇ORA-01105，ORA-01606：

SQL> startup mount; ORACLE instance started. Total System Global Area 9.4869E+10 bytes Fixed Size 2264056 bytes Variable Size 5.0197E+10 bytes Database Buffers 4.4560E+10 bytes Redo Buffers 109174784 bytes ORA-01105: mount is incompatible with mounts by other instances ORA-01606: parameter not identical to that of another mounted instance

数据库节点1目前状态是NOMOUNT.

2.解决过程

错误代码说明：

$ oerr ora 1105 01105, 00000, "mount is incompatible with mounts by other instances" // *Cause: An attempt to mount the database discovered that another instance // mounted a database by the same name, but the mount is not // compatible. Additional errors are reported explaining why. // *Action: See accompanying errors. $ oerr ora 1606 01606, 00000, "parameter not identical to that of another mounted instance" // *Cause: A parameter was different on two instances. // *Action: Modify the initialization parameter and restart.

查询gc_隐含参数

set linesize 333 col name for a35 col description for a66 col value for a30 SELECT i.ksppinm name, i.ksppdesc description, CV.ksppstvl VALUE FROM sys.x$ksppi i, sys.x$ksppcv CV WHERE i.inst_id = USERENV ('Instance') AND CV.inst_id = USERENV ('Instance') AND i.indx = CV.indx AND i.ksppinm LIKE '/_gc%' ESCAPE '/' ORDER BY REPLACE (i.ksppinm, '_', '');

查询结果如下（部分相同值的参数已省略）：

--节点1： _gc_policy_time how often to make object policy decisions in minutes 0 _gc_read_mostly_flush_check if TRUE, optimize flushes for read mostly objects FALSE _gc_read_mostly_locking if TRUE, enable read-mostly locking FALSE --节点2： _gc_policy_time how often to make object policy decisions in minutes 10 _gc_read_mostly_flush_check if TRUE, optimize flushes for read mostly objects FALSE _gc_read_mostly_locking if TRUE, enable read-mostly locking TRUE

发现问题，_gc_policy_time隐藏参数，_gc_read_mostly_locking隐藏参数，2个节点值不一致。

解决方法：根据现在正常运行的节点2的值，重新设置这两个值：

alter system set "_gc_read_mostly_locking"=true scope=spfile sid='*'; alter system set "_gc_policy_time"=10 scope=spfile sid='*'; --正常关闭节点1： shutdown immediate; --正常启动节点1： startup

实际执行过程如下：

SQL> alter system set "_gc_read_mostly_locking"=true scope=spfile sid='*'; System altered. SQL> alter system set "_gc_policy_time"=10 scope=spfile sid='*'; System altered. SQL> shutdown immediate; ORA-01507: database not mounted ORACLE instance shut down. SQL> startup ORACLE instance started. Total System Global Area 9.4869E+10 bytes Fixed Size 2264056 bytes Variable Size 5.1271E+10 bytes Database Buffers 4.3487E+10 bytes Redo Buffers 109174784 bytes Database mounted. Database opened.

至此RAC节点1启动成功。

3.总结

猜测故障原因应该是之前有人修改数据库隐含参数，误操作只修改了一个实例导致。

当我们操作RAC环境时，一定要注意sid='*'这一点。