在Oracle 11g，开启archive log模式时，默认归档目录为db_recovery_file_dest指定。此参数在pfile/spfile中可以指定：

show parameter db_recovery_file_dest

db_recovery_file_dest=/oracle/11g/flash_recovery_area

更改归档模式

需要在mount状态下，更改归档模式。 

SQL> shutdown immediate;

SQL> startup mount

SQL> alterdatabase archivelog;  / alter database noarchivelog

Database altered.

SQL> alter database open;

SQL> archive log list;

sys@ORCL> archive log list;

Database log mode              Archive Mode

Automatic archival             Enabled

Archive destination            USE_DB_RECOVERY_FILE_DEST

Oldest online log sequence     53

Next log sequence to archive   55

Current log sequence           55 

更改log_archive_dest_1参数可更改归档日志目录（pfile/spfile中参数db_recovery_file_dest指定的目录将无效）

 SQL> alter system setlog_archive_dest_1='location=/data/oracle/log1/archive_log';     最后的目录名称需要为archive_log!

System altered.

SQL> archive log list;

Database log mode              Archive Mode

Automatic archival             Enabled

Archive destination            /data/oracle/log1/archive_log

Oldest online log sequence     26

Next log sequence to archive   28

Current log sequence           28

SQL> alter system archive log current;

System altered.

sys@ORCL> select name fromv$archived_log;

NAME

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

/oracle/11g/flash_recovery_area/ORC

L/archivelog/2015_12_11/o1_mf_1_55_

c6nyryhs_.arc 

修改日志文件命名格式：

SQL> alter system setlog_archive_max_processes = 5;

SQL> alter system set log_archive_format= "archive_%t_%s_%r.log" scope=spfile;

 *****************************************************************************************************************

 SQL>archive log list;
如果显示为ENABLE则表示已成功归档
或 SQL>select log_mode fromv$database;
如果为ARCHIVELOG则表示已成功归档

********************************************************************************

SQL> show parameter db_recovery

　　NAME                                     TYPE                        VALUE
------------------------------------        -----------                      ------------------------------
db_recovery_file_dest                 string                      /data/oracle/flash_recovery_area
db_recovery_file_dest_size         biginteger                  4231m

　　可以修改db_recovery_file_dest_size参数的大小

　　SQL>alter system setdb_recovery_file_dest_size=21474836480