版本 11.2.0.1.0
rac1
rac2
linux 5.3U 2.6.18-128.el5
因为要修复一个bug做测试，在一个节点上修改隐含参数，然后重启！在测试的过程中遇到
修改了rac1 上的参数
sys@rac1>alter system set "_gc_read_mostly_locking"=false scope=spfile sid='rac1';
sys@rac1>shutdown immedate
Database closed.
Database dismounted.
ORACLE instance shut down.
在启动的时候遇到如下报错：
sys@rac1> startup
ORACLE instance started.
Total System Global Area 1653518336 bytes
Fixed Size 2213896 bytes
Variable Size 1275070456 bytes
Database Buffers 369098752 bytes
Redo Buffers 7135232 bytes
ORA-01105: mount is incompatible with mounts by other instances
ORA-01606: parameter not identical to that of another mounted instance
报警日志中
ALTER DATABASE MOUNT
NOTE: Loaded library: /opt/oracle/extapi/64/asm/orcl/1/libasm.so
NOTE: Loaded library: System
SUCCESS: diskgroup DATA2 was mounted
NOTE: dependency between database rac and diskgroup resource ora.DATA2.dg is established
ORA-1105 signalled during: ALTER DATABASE MOUNT...
Sun Jul 01 19:17:49 2012
Starting ORACLE instance (normal)
因为节点1修改之后的值为false 而节点2 的值为 ture，导致上面的错误。
解决办法：
因为节点2没有关闭,所以在节点上执行
sys@rac2>alter system set "_gc_read_mostly_locking"=false scope=spfile sid='*';
再次启动rac1 的数据库 就可以成功启动！
拓展一下，如果修改隐含参数的时候sid指定为*,重启一个节点 是ok的！
sys@rac1>alter system set "_gc_read_mostly_locking"=false scope=spfile sid='*';
System altered.
sys@rac1>shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
sys@rac1>startup
ORACLE instance started.
Total System Global Area 1653518336 bytes
Fixed Size 2213896 bytes
Variable Size 1275070456 bytes
Database Buffers 369098752 bytes
Redo Buffers 7135232 bytes
Database mounted.
Database opened.
sys@rac1>
和下面这篇文章不同的是我遇到的隐含参数不一样！不过作为拓展了，多了解一些案例！
http://space.itpub.net/7796861/viewspace-675951
http://space.itpub.net/4227/viewspace-723576
ps 今天做了一次变更，版本是 11.2.0.3 和自己做的测试有出入！希望各位读者 自己实践一下！
