ORA-19808错误一例

一套Linux上的11.2.0.2 RAC系统，其中一个节点startup mount时出现ORA-19808错误，日志如下：

SQL> alter database mount;
alter database mount
*
ERROR at line 1:
ORA-01105: mount is incompatible with mounts by other instances
ORA-19808: recovery destination parameter mismatch


SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Partitioning, Real Application Clusters, OLAP, Data Mining
and Real Application Testing options


[oracle@rh3 ~]$ oerr ora 19808
19808, 00000, "recovery destination parameter mismatch"
// *Cause:  The value of parameters DB_RECOVERY_FILE_DEST and
//          DB_RECOVERY_FILE_DEST_SIZE must be same in all instances.
//          instance. All databases must have same recovery destination
//          parameters.
// *Action: Check DB_RECOVERY_FILE_DEST and DB_RECOVERY_FILE_DEST_SIZE
//          values in all instances.

SQL> col name for a30
SQL> col value for a30

SQL> select name ,value,inst_id from gv$system_parameter  where name='db_recovery_file_dest_size';

NAME                           VALUE                             INST_ID
------------------------------ ------------------------------ ----------
db_recovery_file_dest_size     0                                       1
db_recovery_file_dest_size     42278584320                             2

该错误是由于启动节点使用了pfile形式的参数文件，而该参数文件中的db_recovery_file_dest_size值与已经启动的另一个节点的db_recovery_file_dest_size不一致所造成。

如果使用共享的server parameter file则不可能出现上述情况，当然也可以通过在启动节点上修改db_recovery_file_dest_size来解决问题。