Enable Archive Log Mode
[oracle@oraxxxx ~]$ echo $ORACLE_BASE
/u01/app/oracle
[oracle@oraxxxx ~]$ echo $ORACLE_SID
DB11G
[oracle@oraxxxx ~]$ export
ORACLE_BASE=/u01/app/oracle/product/11.2.0/db_1
[oracle@oraxxxx ~]$ export ORACLE_SID=orcl
[oracle@oraxxxx ~]$ echo $ORACLE_BASE
/u01/app/oracle/product/11.2.0/db_1
[oracle@oraxxxx ~]$ echo $ORACLE_SID
orcl
[oracle@oraxxxx ~]$ sqlplus "/ as sysdba"
SQL*Plus: Release 11.2.0.1.0
Production on Mon Jun 17 11:05:30 2013
Copyright (c) 1982, 2009,
Oracle.  All rights reserved.
Connected to an idle instance.
SQL> startup
ORACLE instance started.
Total System Global Area 1052233728
bytes
Fixed Size                  2220032 bytes
Variable Size             792723456 bytes
Database Buffers          251658240 bytes
Redo Buffers                5632000 bytes
Database mounted.
Database opened.
SQL> archive log list 
Database log
mode             
No Archive Mode 
Automatic
archival            
Disabled 
Archive
destination           
USE_DB_RECOVERY_FILE_DEST 
Oldest online log sequence     25 
Current log
sequence          
27 
SQL>
The log mode is No Archive Mode. Note
that Archive destination is USE_DB_RECOVERY_FILE_DEST. You can determine the path by looking at the parameter RECOVERY_FILE_DEST.
SQL> show parameter recovery_file_dest 
NAME                                
TYPE       
VALUE 
------------------------------------
----------- ------------------------------ 
db_recovery_file_dest               
string      /u01/app/oracle/flash_recovery_area 
db_recovery_file_dest_size          
big integer 3852M 
SQL>
By default, archive logs will be
written to the flash recovery area. If you do not want to write archive logs to
the flash recovery area you can set the parameter LOG_ARCHIVE_DEST_n to the location in which you wish to write archive logs.
Open other terminal and run
blow command:
# mkdir /u01/app/oracle/oradata/orcl/arch
# chown oracle:oinstall /u01/app/oracle/oradata/orcl/arch
# ls –l /u01/app/oracle/oradata/orcl
Change back oracle user
terminal
SQL> alter system set log_archive_dest_1='LOCATION=/u01/app/oracle/oradata/orcl/arch' scope =
both; 
System altered. 
SQL> archive log list; 
Database log
mode             
No Archive Mode 
Automatic
archival            
Disabled 
Archive
destination           
/u01/app/oracle/oradata/orcl/arch 
Oldest online log sequence     25 
Current log
sequence          
27 
SQL>
Now we shutdown the database and
bring it backup in mount mode. 
SQL> shutdown immediate 
Database closed. 
Database dismounted.
ORACLE instance shut down. 
SQL> startup mount 
ORACLE instance started.
Total System Global Area
1052233728 bytes
Fixed Size                  2220032 bytes
Variable Size             792723456 bytes
Database Buffers          251658240 bytes
Redo Buffers                5632000 bytes
Database mounted.
Database opened.
SQL>
Lastly all that is needed it set
archive log mode and open the database.
SQL> alter database archivelog; 
Database altered. 
SQL> alter database open; 
Database altered. 
SQL> archive log list 
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/oradata/orcl/arch
Oldest online log
sequence     224
Next log sequence to
archive   226
Current log sequence           226
SQL>
We can now see that archive log mode
is enabled. 
You can switch to the log file to see
that an archive is written to archive log location.
SQL> alter system switch logfile; 
System altered. 
SQL> host  
[oracle@oraxxxx ~]$ ls /u01/app/oracle/oradata/orcl/arch
1_27_711369564.dbf 
[oracle@ora1 ~]$ exit 
exit 
SQL>
 
===================================================== 
 
Disable Archive Log Mode
[oracle@oraxxxx ~]$ sqlplus "/ as sysdba"
SQL*Plus: Release 11.2.0.1.0
Production on Mon Jun 17 12:25:39 2013
Copyright (c) 1982, 2009,
Oracle.  All rights reserved.
Connected to:
Oracle Database 11g
Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, OLAP,
Data Mining and Real Application Testing options
SQL> archive log list;
Database log mode              Archive Mode
Automatic archival             Enabled
Archive destination            /u01/app/oracle/oradata/orcl/arch
Oldest online log
sequence     224
Next log sequence to
archive   226
Current log sequence           226
SQL>
The Database log mode is Archive
mode. Next we shut down the database and bring up back up in mount mode.
SQL> shutdown immediate 
Database closed. 
Database dismounted.
ORACLE instance shut down. 
SQL> startup mount
ORACLE instance started.
 
Total System Global Area
1052233728 bytes
Fixed Size                  2220032 bytes
Variable Size             792723456 bytes
Database Buffers          251658240 bytes
Redo Buffers                5632000 bytes
Database mounted. 
SQL>
All that is left is to disable
archive log mode and open the database.
SQL> alter database noarchivelog; 
Database altered. 
SQL> alter database open; 
Database altered. 
SQL> archive log list; 
Database log
mode             
No Archive Mode 
Automatic
archival            
Disabled 
Archive
destination           
/u01/app/oracle/oradata/orcl/arch 
Oldest online log sequence     26 
Current log
sequence          
28 
SQL>
Now you can see, ARCHIVELOG mode has been disabled.