解决办法，我们暂时先指定一个目录来存放归档日志。然后再修改三个log_archive_dest_n的系统参数时，指定好scope为spfile，重启实例即可。

SQL> alter system set log_archive_dest_1='location=/logs/log_1';

SQL> alter system archive log current;

System altered.

SQL> alter system set log_archive_dest_1='' scope=spfile;

SQL> alter system set log_archive_dest_2='' scope=spfile;

SQL> alter system set log_archive_dest_3='' scope=spfile;

SQL> startup force

ORACLE instance started.

Total System Global Area 285212672 bytes

Fixed Size 1218992 bytes

Variable Size 104859216 bytes

Database Buffers 176160768 bytes

Redo Buffers 2973696 bytes

Database mounted.

Database opened.

查看一下现在使用的归档的目录，已经成功改回为了DB_RECOVERY_FILE_DEST。

SQL> archive log list;

Database log mode Archive Mode

Automatic archival Enabled

Archive destination USE_DB_RECOVERY_FILE_DEST

Oldest online log sequence 51

Next log sequence to archive 53

Current log sequence 53

最后再查看一下log_archive_dest_n参数，这些参数都没有被设置了，均为空：

SQL> show parameter log_archive_dest

NAME TYPE VALUE

------------------------------------ ----------- ------------------------------

log_archive_dest string

log_archive_dest_1 string

log_archive_dest_10 string

log_archive_dest_2 string

log_archive_dest_3 string

log_archive_dest_4 string

log_archive_dest_5 string

log_archive_dest_6 string

log_archive_dest_7 string

log_archive_dest_8 string

log_archive_dest_9 string

小结：log_archive_dest_n与DB_RECOVERY_FILE_DEST参数都可以用来存放归档日志，但二者的关系是：不设置log_archive_dest_n时，使用DB_RECOVERY_FILE_DEST来存文件；当设置了log_archive_dest_n时，则使用log_archive_dest_n来存放归档日志。

下面我们，再对log_archive_dest_n进行设置，让DB_RECOVERY_FILE_DEST“失效”。

SQL>alter system set log_archive_dest_1='location=/logs/log_1' scope=spfile;

SQL>alter system set log_archive_dest_2='location=/logs/log_2' scope=spfile;

SQL>alter system set log_archive_dest_3='location=/logs/log_3' scope=spfile;

SQL> startup force

ORACLE instance started.

Total System Global Area 285212672 bytes

Fixed Size 1218992 bytes

Variable Size 109053520 bytes

Database Buffers 171966464 bytes

Redo Buffers 2973696 bytes

Database mounted.

Database opened.

我们进行下手动归档

SQL> alter system archive log current;

查看下系统时间，发现三个目录下，都已经有了最新的归档日志：

[root@localhost logs]$ date

Wed Sep 1 10:48:39 CST 2010

[root@localhost logs]# ll -t log_1

-rw-r----- 1 oracle oinstall 280576 Sep 1 10:48 1_54_723037014.dbf

[root@localhost logs]# ll -t log_2

-rw-r----- 1 oracle oinstall 280576 Sep 1 10:48 1_54_723037014.dbf

[root@localhost logs]# ll -t log_3

-rw-r----- 1 oracle oinstall 280576 Sep 1 10:48 1_54_723037014.dbf

而DB_RECOVERY_FILE_DEST目录下，已经不再会存放新的归档日志了：

[oracle@localhost archivelog]$ ll 2010_09_01/

作者“FJXSUNMIT”